CN106233816B

CN106233816B - Transmission method and device for demodulation reference signal

Info

Publication number: CN106233816B
Application number: CN201480078346.1A
Authority: CN
Inventors: 黎超
Original assignee: Huawei Technologies Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2014-05-21
Filing date: 2014-05-21
Publication date: 2020-01-03
Anticipated expiration: 2034-05-21
Also published as: WO2015176255A1; CN106233816A

Abstract

The invention provides a method and a device for transmitting demodulation reference signals, which comprise the following steps: the first equipment determines a position for sending a demodulation reference signal in a physical resource block, wherein the position for sending the demodulation reference signal comprises a mapping position of a channel state information reference signal (CSI-RS) which is used and/or unused by the first equipment, and the demodulation reference signal is used for demodulating data of the second user equipment; the first device sends configuration information to the second user equipment, wherein the configuration information is used for indicating the position of the demodulation reference signal in the physical resource block; the first device transmits the demodulation reference signal at the position of transmitting the demodulation reference signal in the physical resource block. By adopting the technical scheme provided by the embodiment of the invention, the downlink user data demodulation of more users can be supported.

Description

Transmission method and device for demodulation reference signal

Technical Field

The present invention relates to communications technologies, and in particular, to a method and a device for transmitting demodulation reference signals.

Background

The combination of Multiple-Input Multiple-output (MIMO) technology and Orthogonal Frequency Division Multiplexing (OFDM) system raises the transmission capability of the wireless communication system to a new level. A 4 th generation cellular mobile communication system represented by Release-10 (Rel-10 for short) of Long Term Evolution (Long Term Evolution, LTE for short) 10 th edition of protocols supports MIMO with a maximum of 8 transmitting antennas at a base station. The transmission capability of Single User-Multiple-Input-Multiple-output (SU-MIMO for short) is limited by the number of antennas of a Single User and the isolation of the antennas, so that SU-MIMO is currently more mainstream, and 2 cross-polarized antennas can be implemented on a smaller device such as a mobile phone. I.e. currently mainstream SU-MIMO can support up to 2 streams. Further, to improve the transmission capability of the cell, Multi-User-Multiple-Input-Multiple-output (MU-MIMO) can further provide the gain between Multiple users due to the spatial separation of users.

The existing LTE system version Rel-10 supports demodulation reference signals of 8 streams at most, so that the downlink user data demodulation of more users cannot be supported for a multi-user multi-input multi-output scene.

Disclosure of Invention

The invention provides a transmission method and equipment of a demodulation reference signal, which are used for solving the problem that the prior LTE system version Rel-10 can not support the demodulation of downlink user data of more users.

In a first aspect of the present invention, a method for transmitting a demodulation reference signal is provided, including:

the first equipment determines a position for sending a demodulation reference signal in a physical resource block, wherein the position for sending the demodulation reference signal comprises a mapping position of a channel state information reference signal (CSI-RS) which is used and/or unused by the first equipment, and the demodulation reference signal is used for demodulating data of the second user equipment;

the first device sends configuration information to the second user equipment, wherein the configuration information is used for indicating the position of the demodulation reference signal in the physical resource block;

the first device transmits the demodulation reference signal at the position of transmitting the demodulation reference signal in the physical resource block.

In a first possible implementation manner, according to the first aspect, the configuration information is CSI-RS signaling with non-zero power.

In a second possible implementation manner, with reference to the first aspect or the first possible implementation manner, the determining, by the first device, a position where the demodulation reference signal is sent in a physical resource block specifically includes:

and the first equipment determines the position for sending the demodulation reference signal in the physical resource block according to the channel state information of the second user equipment.

In a third possible implementation manner, with reference to the first aspect, the first possible implementation manner, and the second possible implementation manner, before the first device sends the demodulation reference signal at the position in the physical resource block where the demodulation reference signal is sent, the method further includes:

the first device sends a precoding indication to the second user equipment, where the precoding indication is used to indicate precoding information of user data of the second user equipment, so that the second user equipment performs user data demodulation according to the demodulation reference signal and the precoding information, where the demodulation reference signal includes a CSI-RS for performing a channel measurement operation or a first downlink demodulation reference signal DM-RS for performing user data demodulation, and the first DM-RS is a DM-RS mapped on a position, in the physical resource block, where the demodulation reference signal is sent according to a mapping manner of the CSI-RS.

In a fourth possible implementation manner, with reference to the first aspect, the first possible implementation manner, and the second possible implementation manner, before the first device sends the demodulation reference signal at the position in the physical resource block where the demodulation reference signal is sent, the method further includes:

the first device performs precoding on the demodulation reference signal, where the demodulation reference signal is specifically a second DM-RS used for performing user data demodulation, and the second DM-RS is a DM-RS mapped in the physical resource block at the position where the demodulation reference signal is sent according to a preset mapping manner.

In a fifth possible implementation manner, with reference to the first aspect, the first possible implementation manner, the second possible implementation manner, the third possible implementation manner, and the fourth possible implementation manner, before the first device sends the demodulation reference signal in the position where the demodulation reference signal is sent in the physical resource block, the method further includes:

the first device sends first indication information to the second user equipment, wherein the first indication information is used for indicating the position of the second user equipment for carrying out rate matching or interference measurement in a physical resource block.

In a sixth possible implementation manner, with reference to the fifth possible implementation manner, if the physical resource block includes a location for sending a DM-RS to at least one first user equipment, the location indicated by the first indication information includes the location for sending the DM-RS to the at least one first user equipment.

In a seventh possible implementation manner, with reference to the first aspect, the first possible implementation manner, the second possible implementation manner, the third possible implementation manner, the fourth possible implementation manner, the fifth possible implementation manner, and the sixth possible implementation manner, before the first device sends the demodulation reference signal at the position where the demodulation reference signal is sent in the physical resource block, the method further includes:

the first device sends second indication information to the at least one first user equipment, wherein the second indication information is used for indicating the position of the second user equipment for sending the demodulation reference signal, so that the third device carries out rate matching or interference measurement according to the position of the second user equipment for sending the demodulation reference signal.

In an eighth possible implementation manner, with reference to the first aspect, the first possible implementation manner, the second possible implementation manner, the third possible implementation manner, the fourth possible implementation manner, the fifth possible implementation manner, the sixth possible implementation manner, and the seventh possible implementation manner, after the first device sends the demodulation reference signal at the position where the demodulation reference signal is sent in the physical resource block, the method further includes:

the first device sends a third indication signaling to a base station, where the third indication signaling is used to indicate a position where the second user equipment sends a demodulation reference signal, so that the base station reserves the position where the second user equipment sends the demodulation reference signal.

In a second aspect of the present invention, a method for transmitting a demodulation reference signal is provided, including:

the second user equipment receives configuration information sent by the first equipment, wherein the configuration information is used for indicating the position of the demodulation reference signal in the physical resource block;

the second user equipment receives the demodulation reference signal sent by the first equipment at a position indicated by the configuration information in the physical resource block, wherein the position indicated by the configuration information comprises a mapping position of used and/or unused CSI-RS of the first equipment, and the demodulation reference signal is used for demodulating data of the second user equipment.

In a first possible implementation manner, according to the second aspect, before the second user equipment receives the demodulation reference signal sent by the first equipment at a position indicated by the configuration information in the physical resource block, the method further includes:

the second user equipment receives a precoding indication sent by the first equipment;

the second user equipment acquires the pre-coding information of the user data of the second user equipment according to the pre-coding indication;

after the second user equipment receives the demodulation reference signal sent by the first equipment at the position indicated by the configuration information in the physical resource block, the method further includes:

the second user equipment demodulates user data according to the demodulation reference signal and the precoding information;

the demodulation reference signal comprises a CSI-RS used for executing channel measurement operation or a first downlink demodulation reference signal DM-RS used for executing user data demodulation, and the first DM-RS is a DM-RS mapped on the position of the physical resource block where the demodulation reference signal is sent according to a mapping mode of the CSI-RS.

In a second possible implementation manner, according to the second aspect, the demodulation reference signal is a second DM-RS used for performing user data demodulation after being precoded, and the second DM-RS is a DM-RS mapped on the position, in the physical resource block, where the demodulation reference signal is sent according to a preset mapping manner.

In a third possible implementation manner, with reference to the second aspect, the first possible implementation manner, and the second possible implementation manner, before the second user equipment receives the demodulation reference signal sent by the first equipment at a position indicated by the configuration information in the physical resource block, the method further includes:

the second user equipment receives first indication information sent by the first equipment, wherein the first indication information is used for indicating the position of the second user equipment for carrying out rate matching or interference measurement in a physical resource block;

and the second user equipment performs rate matching or interference measurement according to the position in the physical resource block indicated by the first indication information.

In a third aspect of the present invention, there is provided a first apparatus comprising:

a determining module, configured to determine a location for sending a demodulation reference signal in a physical resource block, where the location for sending the demodulation reference signal includes a mapping location of a channel state information reference signal CSI-RS that has been used and/or is not used by the first device, and the demodulation reference signal is used for demodulating data of the second user equipment;

a sending module, configured to send configuration information to the second user equipment, where the configuration information is used to indicate a position of the demodulation reference signal in the physical resource block;

the sending module is further configured to send the demodulation reference signal at the position where the demodulation reference signal is sent in the physical resource block.

In a first possible implementation manner, according to the third aspect, the determining module is specifically configured to:

and determining the position of sending the demodulation reference signal in the physical resource block according to the channel state information of the second user equipment.

In a second possible implementation manner, with reference to the third aspect or the first possible implementation manner, the sending module is further configured to:

and sending a precoding indication to the second user equipment, where the precoding indication is used to indicate precoding information of user data of the second user equipment, so that the second user equipment demodulates the user data according to the demodulation reference signal and the precoding information, where the demodulation reference signal includes a CSI-RS for performing a channel measurement operation or a first downlink demodulation reference signal DM-RS for performing user data demodulation, and the first DM-RS is a DM-RS mapped on a position, in the physical resource block, where the demodulation reference signal is sent according to a CSI-RS mapping manner.

In a third possible implementation manner, with reference to the third aspect or the first possible implementation manner, the first device further includes:

and the coding module is configured to precode the demodulation reference signal, where the demodulation reference signal is specifically a second DM-RS used for performing user data demodulation, and the second DM-RS is a DM-RS mapped in the position where the demodulation reference signal is sent in the physical resource block according to a preset mapping manner.

In a fourth possible implementation manner, with reference to the third aspect, the first possible implementation manner, the second possible implementation manner, and the third possible implementation manner, the sending module is further configured to:

and sending first indication information to the second user equipment, wherein the first indication information is used for indicating the position of the second user equipment for carrying out rate matching or interference measurement in a physical resource block.

In a fifth possible implementation manner, with reference to the third aspect, the first possible implementation manner, the second possible implementation manner, the third possible implementation manner, and the fourth possible implementation manner, the sending module is further configured to:

and sending second indication information to the at least one first user equipment, wherein the second indication information is used for indicating the position of sending the demodulation reference signal by the second user equipment, so that the at least one first user equipment carries out rate matching or interference measurement according to the position of sending the demodulation reference signal by the second user equipment.

In a sixth possible implementation manner, with reference to the third aspect, the first possible implementation manner, the second possible implementation manner, the third possible implementation manner, the fourth possible implementation manner, and the fifth possible implementation manner, the sending module is further configured to:

and sending a third indication signaling to a base station, wherein the third indication signaling is used for indicating the position of the second user equipment for sending the demodulation reference signal, so that the base station reserves the position of the second user equipment for sending the demodulation reference signal.

In a fourth aspect of the present invention, there is provided a second user equipment, including:

a receiving module, configured to receive configuration information sent by a first device, where the configuration information is used to indicate a position of the demodulation reference signal in a physical resource block;

a determining module, configured to determine, according to the configuration information received by the receiving module, a position of the demodulation reference signal in the physical resource block;

the receiving module is further configured to receive the demodulation reference signal sent by the first device at the position of the demodulation reference signal in the physical resource block determined by the determining module, where the position of the demodulation reference signal in the physical resource block determined by the determining module includes a mapping position of CSI-RSs already used and/or unused by the first device, and the demodulation reference signal is used for demodulating data of the second user equipment.

In a first possible implementation manner, according to the fourth aspect, the receiving module is further configured to:

receiving a precoding indication sent by the first equipment;

acquiring precoding information of user data of the second user equipment according to the precoding indication;

the second user equipment further comprises:

the demodulation module is used for demodulating the user data according to the demodulation reference signal and the precoding information;

In a second possible implementation manner, with reference to the fourth aspect or the first possible implementation manner, the receiving module is further configured to:

receiving first indication information sent by the first device, where the first indication information is used to indicate a position where the second user equipment performs rate matching or interference measurement in a physical resource block;

and carrying out rate matching or interference measurement according to the position in the physical resource block indicated by the first indication information.

In a fifth aspect of the present invention, there is provided a first apparatus comprising:

a processor, configured to determine a location in a physical resource block to transmit a demodulation reference signal, where the location to transmit the demodulation reference signal includes a mapping location of a channel state information reference signal (CSI-RS) that has been used and/or is not used by the first device, and the demodulation reference signal is used for demodulating data of the second user equipment;

a transmitter, configured to transmit configuration information to the second user equipment, where the configuration information is used to indicate a position of the demodulation reference signal in the physical resource block;

the transmitter is further configured to transmit the demodulation reference signal at the position of the physical resource block where the demodulation reference signal is transmitted.

In a first possible implementation manner, according to the fifth aspect, the processor is specifically configured to:

In a second possible implementation manner, with reference to the fifth aspect or the first possible implementation manner, the transmitter is further configured to:

In a third possible implementation manner, with reference to the fifth aspect or the first possible implementation manner, the processor is further configured to:

and precoding the demodulation reference signal, wherein the demodulation reference signal is specifically a second DM-RS used for executing user data demodulation, and the second DM-RS is a DM-RS mapped on the position of the sending demodulation reference signal in the physical resource block according to a preset mapping mode.

In a fourth possible implementation manner, with reference to the fifth aspect, the first possible implementation manner, the second possible implementation manner, and the third possible implementation manner, the transmitter is further configured to:

In a fifth possible implementation manner, with reference to the fifth aspect, the first possible implementation manner, the second possible implementation manner, the third possible implementation manner, and the fourth possible implementation manner, the transmitter is further configured to:

In a sixth possible implementation manner, with reference to the fifth aspect, the first possible implementation manner, the second possible implementation manner, the third possible implementation manner, the fourth possible implementation manner, and the fifth possible implementation manner, the transmitter is further configured to:

In a sixth aspect of the present invention, there is provided a second user equipment, comprising:

a receiver, configured to receive configuration information sent by a first device, where the configuration information is used to indicate a position of the demodulation reference signal in a physical resource block;

a processor configured to determine a position of the demodulation reference signal in the physical resource block according to the configuration information received by the receiver;

the receiver is further configured to receive the demodulation reference signal sent by the first device at a position of the demodulation reference signal in the physical resource block determined by the processor, the position of the demodulation reference signal in the physical resource block determined by the processor includes a mapping position of CSI-RSs already used and/or unused by the first device, and the demodulation reference signal is used for demodulating data of the second user equipment.

In a first possible implementation manner, according to the sixth aspect, the receiver is further configured to:

receiving a precoding indication sent by the first equipment;

the processor is further configured to demodulate user data according to the demodulation reference signal and the precoding information;

In a second possible implementation manner, with reference to the sixth aspect or the first possible implementation manner, the receiver is further configured to:

In the transmission method of the demodulation reference signal according to the embodiment of the present invention, the first device determines a position where the demodulation reference signal is sent in the physical resource block, and sends configuration information to the second user equipment to indicate the position of the demodulation reference signal in the physical resource block. The position for sending the demodulation reference signal comprises the mapping position of the channel state information reference signal (CSI-RS) which is already used and/or unused by the first equipment, so that the first equipment sends the demodulation reference signal at the mapping position of the CSI-RS in the physical resource block defined in the existing LTE system release Rel-10, and therefore, the downlink user data demodulation of more users can be supported.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

FIG. 1 is a resource mapping diagram of a reference signal in a physical resource block pair under a normal cyclic prefix of LTE Rel-10;

fig. 2 is a flowchart of a method for transmitting a demodulation reference signal according to an embodiment of the present invention;

fig. 3 is a flowchart of a method for transmitting a demodulation reference signal according to a second embodiment of the present invention;

fig. 4 is an interaction flowchart of a first device and a second user equipment according to a third embodiment of the present invention;

FIG. 5 is a resource map of CSI-RS of a 4-antenna port in one PRB pair under a normal cyclic prefix of LTE Rel-10;

FIG. 6 is a resource map of CSI-RSs of two configured 2-antenna ports in one PRB pair under a normal cyclic prefix of LTE Rel-10;

FIG. 7 is a resource map of CSI-RS of a next 8-antenna port in one PRB pair under a normal cyclic prefix of LTE Rel-10;

fig. 8 is a resource map for MU-MIMO where the second user equipment performs space division multiplexing with the first user equipment;

fig. 9 is an interaction flowchart of a first device and a second user equipment according to a fourth embodiment of the present invention;

fig. 10 is a resource map of MU-MIMO where two second user equipments space-division multiplex in one PRB pair under a normal cyclic prefix;

fig. 11 is a resource map of MU-MIMO when four second user equipments perform space division multiplexing in one PRB pair under a normal cyclic prefix;

fig. 12 is a diagram of rate matching in MU-MIMO with space division multiplexing of four second user equipments in one PRB pair under a normal cyclic prefix;

fig. 13 is an interaction flowchart of a first device and a first user equipment according to a fifth embodiment of the present invention;

fig. 14 is a schematic structural diagram of a first apparatus according to a sixth embodiment of the present invention;

fig. 15 is a schematic structural diagram of a first apparatus according to a seventh embodiment;

fig. 16 is a schematic structural diagram of a second apparatus according to an eighth embodiment;

fig. 17 is a schematic structural diagram of a second apparatus according to the ninth embodiment;

fig. 18 is a schematic structural diagram of a first apparatus provided in this embodiment;

fig. 19 is a schematic structural diagram of a second apparatus provided in the eleventh embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 1 is a resource mapping diagram of a reference signal in one physical resource block pair under a normal cyclic prefix of LTE Rel-10. In a wideband system, particularly an OFDM system, the resource blocks are divided from both the time and frequency domain directions. Referring to the description of Resource blocks in the Physical layer protocol of LTE, one Physical Resource Block (PRB) corresponds to 180 khz in the frequency domain and one slot in the time domain, that is, 0.5 ms. Under a normal cyclic prefix (normal cyclic prefix), a slot may transmit 7 consecutive OFDM symbols, and one PRB represents 7 consecutive OFDM symbols in a time domain and 12 subcarriers in a frequency domain, so that one PRB is composed of 7 × 12 Resource Elements (REs). One PRB pair consists of two PRBs, i.e. occupies 14 × 12 REs. As shown in fig. 1, the PRB pairs in the figure are composed of different patterns of RE small squares, two groups of 0, 1, 2 … …, 6 numbers along the x-axis direction, 7 OFDM symbols respectively representing the first slot and the second slot, and 0, 1, 2 … …, 11 numbers along the y-axis direction represent 12 subcarriers consecutive in the frequency domain.

Specifically, in fig. 1, one PRB pair may be occupied by a Downlink Control Channel (PDCCH for short) and a Downlink shared Channel (PDSCH for short). Wherein, the PDCCH is used for transmitting control information, and occupies the first 3 OFDM symbols of the first time slot and 12 consecutive subcarriers in the frequency domain, that is, 3 × 12 REs; the PDSCH is used to transmit User Equipment (UE) data, and occupies the rest of the REs in a PRB pair, and the demodulation reference signal in the present invention is transmitted in the PDSCH for demodulating the User data transmitted on the PDSCH. The following focuses on the reference signals in one PRB pair. The Reference signals mainly include a Common Reference Signal (CRS), a Channel state information Reference Signal (CSI-RS) and a downlink demodulation Reference Signal (DM-RS), resource occupation positions of antenna ports for transmitting the CRS in one PRB pair are represented by horizontal stripe REs, available resource positions of all CSI-RSs are represented by cross stripe REs, available resource positions of all DM-RSs are represented by positive 45 ° diagonal stripe REs, and other REs are used for transmitting Common control signaling or user data.

Specifically, the existing LTE Rel-10 configures eight antenna ports for CSI-RS in total, and 40 possible mapping positions of all CSI-RS on one PRB pair, that is, all cross-stripe REs in fig. 1; the available resource positions of all the DM-RSs are 24 REs, and each DM-RS port corresponds to 12 REs in the available resource positions of the DM-RS, and every four DM-RSs orthogonally occupy the same RE position, so the 24 REs correspond to 8 DM-RS antenna ports for transmitting the DM-RSs, and thus the prior art supports data demodulation of at most 8 data streams.

Further, the transmission of the CSI-RS may employ 1, 2, 4, or 8 antenna ports. Under each antenna port number, the CSI-RS has a plurality of different position mapping modes. Table 1 shows an indication of the location mapping manner of CSI-RS with different antenna port numbers in different subframe structures of the conventional cyclic prefix. Table 2 gives the subframe configuration of CSI-RS. The configuration number and the position of the CSI-RS on different antenna ports are used for indicating the position mapping mode of the CSI-RS in a physical resource block in the table 1, and the subframe configuration of the CSI-RS, the transmission period of the CSI-RS and the subframe offset of the CSI-RS are used for indicating the sequence number of the subframe for transmitting the CSI-RS in the table 2.

TABLE 1

TABLE 2

Subframe configuration I of CSI-RS_CSI-RS	CSI-RS transmission period T_CSI-RS	CSI-RS subframe offset delta_CSI-RS
			0-4	5	I_CSI-RS
5-14	10	I_CSI-RS-5
			15-34	20	I_CSI-RS-15
35-74	40	I_CSI-RS-35
			75-154	80	I_CSI-RS-75

Specifically, in table 1, k 'and l' are variables for calculating the mapping position of the CSI-RS on one PRB pair, k 'may be calculated by the sequence number of the OFDM symbol where one RE is located, and l' may be calculated by the sequence number of the OFDM symbol where one RE is locatedCalculated by the sequence number of the subcarrier in which one RE is located, n_sThe number of the time slot for currently sending the CSI-RS is 0 or 1; frame structure 1 refers to a Time Division Duplex (TDD) frame structure of LTE, and frame structure 2 refers to a Frequency Division Duplex (FDD) frame structure of LTE; the CSI-RS configuration numbers represent different CSI-RS position mapping modes, 20 configurations exist in a frame structure 1, and 32 configurations exist in a frame structure 2; the number of antenna ports configured for the CSI-RS indicates the number of antenna ports for transmitting the CSI-RS, and the value of the number may be 1, 2, 4, or 8.

Further, table 2 shows the subframe configuration I of the CSI-RS_CSI-RSCSI-RS transmission period T_CSI-RSAnd subframe offset Δ of CSI-RS_CSI-RS. Wherein the transmission period T_CSI-RSThe unit of (1) is 1 subframe, i.e., 1 msec. Specifically, the sending period of the CSI-RS indicates an interval between subframe numbers for sending the CSI-RS, and a value of the CSI-RS subframe offset is determined by the subframe configuration of the CSI-RS, and is used for indicating the initial sending subframe number of the CSI-RS. As can be seen from table 2, on the premise that the transmission period of the CSI-RS is determined, the number of values of the subframe configuration of the CSI-RS and the subframe offset of the CSI-RS is the same. For example, if the transmission period of the CSI-RS is configured to be 5 milliseconds, both the subframe configuration of the CSI-RS and the subframe offset of the CSI-RS can be configured to be any integer value from 0 to 4, if the subframe configuration of the CSI-RS is set to 0, the value of the subframe offset of the CSI-RS is also 0, and in this configuration, the CSI-RS is transmitted on subframes with subframe numbers of 0, 5, and 10 … …, that is, every 5 subframes are transmitted once; similarly, if the subframe configuration of the CSI-RS is set to 1, it means that the CSI-RS is transmitted on the subframe with the subframe number of 1, 6, 11 … …; similarly, if the sending period of the CSI-RS is configured to be 10 milliseconds, the subframe configuration of the CSI-RS may be configured to be any integer value in 5-14, and if the subframe configuration of the CSI-RS is set to be 5, the value of the CSI-RS subframe offset is 0, under such configuration, the CSI-RS may be sent on subframes with subframe numbers of 0, 10, and 20 … …, that is, every 10 subframes are sent once, and the rest configurations are similar, and are not described herein again.

Further, as can be seen from table 1, there may be 20 or 32 different location mapping manners for CSI-RSs sent by the 1-antenna port and the 2-antenna port, and the CSI-RS in each location mapping manner occupies 2 REs on one PRB pair; the CSI-RS sent by the 4 antenna ports can have 10 different position mapping modes, and the CSI-RS under each position mapping mode occupies 4 REs on one PRB pair; the CSI-RS transmitted by the 8 antenna ports may have 5 different position mapping manners, and the CSI-RS in each position mapping manner occupies 8 REs on one PRB pair. In actual use, the time and frequency location of transmitting the CSI-RS may be indicated according to table 1 and table 2.

Furthermore, in existing protocols, the base station may configure a zero-power CSI-RS or a non-zero-power CSI-RS for the UE. Specifically, the base station may issue a zero-power CSI-RS signaling to indicate the zero-power CSI-RS for the UE, so that the UE may perform interference measurement at a mapping position of the CSI-RS indicated by the zero-power CSI-RS signaling; the base station can also issue a non-zero power CSI-RS signaling to indicate the non-zero power CSI-RS for the UE, so that the UE can measure Channel State Information (CSI for short) at the mapping position of the CSI-RS indicated by the non-zero power CSI-RS signaling. The two signaling structures are the same, and both are for indicating the mapping position of the CSI-RS, and are collectively referred to as CSI-RS configuration information.

It should be noted that the schemes of the embodiments of the present invention are all performed in units of PRBs, and are also applicable to the mapping manner in units of PRB pairs. In order to more clearly describe the relationship between one PRB pair and other signals, and to more clearly illustrate the scheme of the embodiment of the present invention, the resource mapping pattern in the subsequent embodiments of the present specification is illustrated based on the PRB pair in fig. 1.

Fig. 2 is a flowchart of a method for transmitting a demodulation reference signal according to an embodiment of the present invention. As shown in fig. 2, the method for transmitting demodulation reference signals of this embodiment may include the following steps:

step S100, the first device determines a position for sending a demodulation reference signal in a physical resource block, wherein the position for sending the demodulation reference signal comprises a mapping position of CSI-RS used and/or unused by the first device, and the demodulation reference signal is used for demodulating data of the second user equipment.

Step S101, the first device sends configuration information to the second user device, wherein the configuration information is used for indicating the position of the demodulation reference signal in the physical resource block.

Step S102, the first device sends the demodulation reference signal at the position where the demodulation reference signal is sent in the physical resource block.

In this embodiment, the main execution body of each step is a first device, and in practice, the first device may be a network device, such as a base station and a relay node, or a UE having an inter-UE communication function. When the first device is a base station, the demodulation reference signal is correspondingly a demodulation reference signal which is sent by the base station to the second user equipment and used for data demodulation of the second user equipment, and therefore the demodulation reference signal can be called a downlink demodulation reference signal; when the first device is a User Equipment (UE), the demodulation reference signal is still used for data demodulation of the second UE, but there is no uplink or downlink component.

Since the prior art implements user data demodulation by using DM-RS, and the resource location of the available DM-RS is limited, as described in fig. 1, the prior DM-RS cannot simultaneously support data demodulation of more than 8 data streams, if each data stream corresponds to one user, that is, the prior art can simultaneously support at most 8 users.

In this embodiment, the first device may not transmit the demodulation reference signal at the location of the DM-RS, but use the available resource location of the CSI-RS as shown in fig. 1 as the location to transmit the demodulation reference signal, thereby implementing data demodulation for more users. Specifically, the position for transmitting the demodulation reference signal includes a mapping position of any one of used CSI-RS, unused CSI-RS, and used CSI-RS.

As a possible implementation, the first device may determine to transmit the demodulation reference signal at the mapping position of the CSI-RS that it has used. That is, the first device may determine to transmit the demodulation reference signal to the second user equipment with the mapped location that has been used to transmit the CSI-RS of the first user equipment. It should be noted that, here, the first user equipment, hereinafter referred to as a first UE, indicates a UE corresponding to an old LTE version, and the second user equipment, hereinafter referred to as a second UE, is a UE corresponding to a new LTE version, where the old LTE version refers to a version of an LTE protocol before the introduction of the present application, and the new LTE version refers to an LTE version before the introduction of the present application. Unless otherwise specified, the second UE, the first UE, the new LTE version, and the old LTE version, described below, follow the definitions herein.

As another possible implementation, the first device may determine to transmit the demodulation reference signal at a mapping position of the CSI-RS that it does not use. That is, the first device may subtract the mapping positions that have been used to transmit the CSI-RS of the first UE from the mapping positions of all its available CSI-RS and then determine to transmit the demodulation reference signal with the mapping positions of the remaining CSI-RS.

As another possible implementation, the first device may also determine the position of transmitting the demodulation reference signal by using a combination of the two implementations. That is, the first device may determine to transmit the demodulation reference signal to the second UE with the mapping positions that have been used to transmit the CSI-RS of the first UE, subtract the mapping positions that have been used to transmit the CSI-RS of the first UE from the mapping positions of all its available CSI-RS, and then determine to transmit the demodulation reference signal with the mapping positions of the remaining CSI-RS.

It should be noted that, the above three possible embodiments only limit the position where the first device transmits the demodulation reference signal not to exceed the mapping position that the first device already uses, or does not use, or already uses the mapping position of the unused CSI-RS, and do not specifically limit how the demodulation reference signal is specifically mapped to the mapping position that the first device already uses, or does not use, or already uses the mapping position of the unused CSI-RS, that is, specifically referring to fig. 1, if the mapping position of the CSI-RS that the first device can use (including the mapping position that the first device already uses the unused CSI-RS) is the resource position composed of all cross-striped REs, then the position where the first device transmits the demodulation reference signal on one PRB pair does not exceed the resource position composed of all cross-striped REs in fig. 1.

Further, the demodulation reference signal may be a CSI-RS, or may be a first DM-RS or a second DM-RS. Specifically, the CSI-RS is a reference signal used to perform a Channel State Information (CSI) measurement operation in the prior art; the first DM-RS is a demodulation reference signal which is not precoded and is used for data demodulation, and is mapped to the position of the sending demodulation reference signal in a physical resource block according to the mapping mode of CSI-RS in terms of resource mapping mode; the second DM-RS is a precoded demodulation reference signal for data demodulation, and in terms of resource mapping, the second DM-RS is a DM-RS mapped in a preset mapping manner on a position where the demodulation reference signal is transmitted in a physical resource block, where the preset mapping manner may be any preset manner different from a mapping manner of the CSI-RS.

It should be noted that, the first DM-RS and the second DM-RS are both different from the DM-RS in the prior art, that is, the DM-RS on the positive 45 ° diagonal line RE in fig. 1, and the difference here is only that the mapping positions of the first DM-RS and the second DM-RS in one PRB pair are different, but the specific sequence generation manner is not limited, and may be the same as or different from the existing DM-RS, or may be the same as or different from the existing CSI-RS. Specifically to fig. 1, the first DM-RS and the second DM-RS are not mapped on the positive 45 ° diagonal RE, but are mapped on the resource location composed of the cross-striped RE.

After the first device determines the position of sending the demodulation reference signal in the physical resource block, in order to ensure that the second UE can perform data demodulation by using the demodulation reference signal, the first device may send configuration information to the second UE, where the configuration information is used to indicate the position of the demodulation reference signal in the physical resource block.

After the first device determines the position for sending the demodulation reference signal and sends the configuration information, the first device may send the demodulation reference signal at the position for sending the demodulation reference signal in the physical resource block. Since the first device transmits the configuration information, the second UE may receive the demodulation reference signal at the position where the demodulation reference signal is transmitted in the physical resource block according to the configuration information, thereby completing data demodulation.

It should be noted that, the execution sequence of the three steps is not specifically limited, and in practice, the execution sequence of the three steps can be flexibly adjusted according to needs.

In addition, the number of the second UEs is not limited, that is, the demodulation reference signals may be used for data demodulation of at least one second UE, that is, the first device may send its respective demodulation reference signal to at least one second UE in the same physical resource block only by ensuring that the position set of the demodulation reference signals sent to the plurality of second UEs does not exceed the position where the demodulation reference signal is sent, so that the at least one second UE may use the same time and frequency domain resource and complete respective data demodulation according to the respective demodulation reference signals.

In the transmission method of the demodulation reference signal according to the embodiment, the first device determines a position in the physical resource block to transmit the demodulation reference signal, where the position to transmit the demodulation reference signal includes a mapping position of CSI-RS that the first device has used, or is not used, or has used plus not used, and transmits configuration information to the second UE to indicate the position of the demodulation reference signal in the physical resource block, so that the second UE can perform data demodulation according to the received demodulation reference signal. Since the first device transmits the demodulation reference signal with the above-described position where the demodulation reference signal is transmitted, data demodulation of more users can be supported.

Fig. 3 is a flowchart of a method for transmitting a demodulation reference signal according to a second embodiment of the present invention. As shown in fig. 3, the method for transmitting demodulation reference signals of this embodiment may include the following steps:

step S200, the second UE receives configuration information sent by the first device, where the configuration information is used to indicate a position of a demodulation reference signal in a physical resource block.

Step S201, the second UE receives a demodulation reference signal sent by the first device at a position indicated by configuration information in a physical resource block, where the position indicated by the configuration information includes a mapping position of a CSI-RS that the first device has used and/or is not using, and the demodulation reference signal is used for demodulating data of the second user equipment.

In this embodiment, the main execution body of each step is the second UE, and in practice, the second UE may be a UE corresponding to the new LTE release.

After the first device sends the configuration information and the demodulation reference signal to the second UE, the second UE needs to receive the configuration information and the demodulation reference signal.

The second UE may determine a position of the demodulation reference signal in the physical resource block according to the received configuration information, and receive the demodulation reference signal at a position indicated by the configuration information.

In the method for transmitting a demodulation reference signal according to the embodiment, the second UE receives the demodulation reference signal at the position indicated by the configuration information in the physical resource block according to the configuration information, so as to perform data demodulation according to the demodulation reference signal. Since the demodulation reference signal of the second UE is at the mapping position of the CSI-RS already used, or unused, or already used plus unused, the data demodulation of more users can be achieved.

Fig. 4 is an interaction flowchart of a first device and a second user equipment according to a third embodiment of the present invention. This embodiment details a specific interaction process between the first device and the second user equipment, that is, the second UE, when the demodulation reference signal sent by the first device is the CSI-RS or the first DM-RS. As shown in fig. 4, the method for transmitting demodulation reference signals of this embodiment may include the following steps:

step S300, the first device determines the position for sending the CSI-RS or the first DM-RS in the physical resource block.

The main execution body of this step is the first device, and in practice, this first device may be a network device, such as a base station or a relay node, or may be a UE having an inter-UE communication function.

Specifically, the first device may determine a location to transmit the CSI-RS or the first DM-RS. The above-mentioned position for transmitting the CSI-RS or the first DM-RS includes a mapping position that has been used, or has not been used, or has been used plus unused CSI-RS. The mapping position of the CSI-RS is a position set of all REs used for placing the CSI-RS in a physical resource block defined in the long term evolution LTE system release Rel-10. Specifically, fig. 1 is a resource location composed of all cross-striped REs.

As a first case, when the location at which the CSI-RS or the first DM-RS is transmitted is a CSI-RS mapping location already used by the first device, the first device determines that the location at which the CSI-RS or the first DM-RS is transmitted to the second UE is the same as the mapping location of the CSI-RS transmitted to the first UE. Specifically, as a possible implementation manner, the first device may transmit the CSI-RS as a demodulation reference signal of the second UE. Since the CSI-RS is sent in full bandwidth, the second UE may also receive the CSI-RS sent by the first device to the first UE, that is, the demodulation reference signal sent by the first device to the second UE at the mapping position of the CSI-RS is the CSI-RS sent to the first UE at the mapping position of the CSI-RS. As another possible implementation, the first device may transmit the first DM-RS as a demodulation reference signal for the second UE. That is, the first device may send the first DM-RS at the mapping position of the CSI-RS of the first UE, and of course, since the mapping position of the CSI-RS is already used to place the CSI-RS of the first UE, and then the first DM-RS is sent to the second UE at the same position, interference may be generated, so this implementation may be a suboptimal solution. In this case, in general, the first device does not need to configure a new mapping position of the CSI-RS for the second UE, and does not need to send the new CSI-RS for the second UE, but only needs to notify the second UE to perform data demodulation at the mapping position of the CSI-RS of the existing device.

As a second case, when the position for transmitting the CSI-RS or the first DM-RS is a mapping position of a CSI-RS unused by the first device, the first device determines the position for transmitting the demodulation reference signal to the second UE to be a mapping position of a CSI-RS remaining after the mapping positions of all available CSI-RSs of the first device are subtracted from the mapping positions of the CSI-RS already used to transmit the first UE. Specifically, as a possible implementation manner, the first device may transmit the CSI-RS as a demodulation reference signal of the second UE. . Since the first device does not use the CSI-RS mapping position at this time, the first device may transmit the CSI-RS at the unused CSI-RS mapping position as a demodulation reference signal. Different from the case that the first device sends the CSI-RS at the mapping position of the already-used CSI-RS as the demodulation reference signal, at this time, the first device does not multiplex the mapping position of the already-used CSI-RS, but sends the demodulation reference signal using the new mapping position of the CSI-RS, that is, the first device needs to configure CSI-RS resources for the second UE as the demodulation reference signal except for the CSI-RS of the first UE. As another possible implementation, the first device may transmit the first DM-RS as a demodulation reference signal for the second UE. The situation at this time is similar to that of the first implementation in this paragraph, except that the sequence generation manner of the first DM-RS may be different from that of the CSI-RS.

As a third case, when the location where the CSI-RS or the first DM-RS is transmitted is a mapping location where the first device has used plus an unused CSI-RS, the first device determines a location where a demodulation reference signal is transmitted to the second UE to be a sum of mapping locations where the first device has used plus an unused CSI-RS. Specifically, when the position for sending the CSI-RS or the first DM-RS is the mapping position of the used CSI-RS, the specific implementation manner is the same as the description of the first case, and when the position for sending the CSI-RS or the first DM-RS is the mapping position of the unused CSI-RS, the specific implementation manner is the same as the description of the second case, which is not described herein again.

It should be noted that, because the CSI-RS is used for measuring Channel State Information (CSI for short), the first device does not precode the CSI-RS when sending the CSI-RS, and therefore, when the demodulation reference signal is the CSI-RS, the first device further needs to send precoding indication Information to the second UE, so that the second UE can perform data demodulation according to the CSI-RS and the precoding Information. Since the first DM-RS is also not precoded, precoding indication information needs to be sent for the second UE, as in the CSI-RS case.

In addition, in the existing LTE Rel-10, the CSI-RS is transmitted to the existing UE in full bandwidth, and in the above scheme, when the demodulation reference signal is the CSI-RS, the first device may determine to transmit the CSI-RS in full bandwidth or dedicated bandwidth of the second UE. Likewise, the first device may also determine to transmit the first DM-RS over the full bandwidth or the dedicated bandwidth of the second UE. That is, the transmission bandwidth of the demodulation reference signal is not limited here.

Step S301, the first device sends configuration information to the second UE, wherein the configuration information is used for indicating the position of the CSI-RS or the first DM-RS in the physical resource block.

The main execution body of this step is the first device, and in practice, the first device may be a network device, such as a base station or a relay node, or may be a UE having an inter-UE communication function.

Specifically, after determining the position of sending the CSI-RS or the first DM-RS in the physical resource block, the first device further needs to send configuration information to the second UE, so as to indicate the position of the CSI-RS or the first DM-RS in the physical resource block.

Further, as can be seen from the foregoing definition of the first DM-RS, the first DM-RS is also mapped into the physical resource block according to the mapping manner of the CSI-RS, and therefore, the first device may use the non-zero power CSI-RS signaling defined in LTE Rel-10 as configuration information to notify the second UE of the location of the demodulation reference signal in the physical resource block.

The non-zero power CSI-RS signaling is a signaling which is issued by a base station to UE and used for indicating the position of the CSI-RS in a physical resource block. Specifically, the CSI-RS signaling with non-zero power includes the following parameters in tables 1 and 2: the configuration number of the CSI-RS, the configuration number of antenna ports of the CSI-RS, the configuration of subframes for transmitting the CSI-RS, the transmission period of the CSI-RS and the subframe offset of the CSI-RS. Through the above parameters, the first device may indicate the position of the demodulation reference signal in the physical resource block for the second UE.

Specifically, for the first DM-RS, the non-zero power CSI-RS signaling further includes a ratio p-C of power on each RE of the PDSCH and Energy (EPRE) of each resource Element at the position where the CSI-RS or the first DM-RS is transmitted, and a unit of the ratio is decibel (dB). For example, if p-C is-3, it indicates that the power on the PDSCH signal is 1/2 of the power of the signal at the position of the above-described transmission CSI-RS or first DM-RS.

Optionally, the first device may place the configuration Information in Downlink Control Information (DCI), and then send the configuration Information to the second UE to indicate a position of the CSI-RS or the first DM-RS in the physical resource block. Of course, considering that there are many signaling words corresponding to the CSI-RS signaling with non-zero power, the first device may also use a Radio Resource Control (RRC) signaling to indicate to the second UE, and when indicating, the first device needs to explicitly specify that the mapping position of the CSI-RS indicated by the CSI-RS signaling with non-zero power is used for data demodulation of the second UE.

Step S302, the first equipment sends a precoding indication to the second UE.

Specifically, since neither the CSI-RS nor the first DM-RS is precoded, and the data sent by the first device to the second UE is precoded data, in order to enable the second UE to perform data demodulation, the first device further needs to send a precoding indication to the second UE, where the precoding indication is used to indicate precoding information of user data of the second UE, so that the second UE can perform data demodulation according to the CSI-RS or the first DM-RS and the precoding information.

Optionally, according to the existing protocol specification of LTE Rel-10 regarding user data precoding, the first device needs to use at least two signaling words to indicate the precoding information, where one signaling word is a Transmit Precoding Matrix Indicator (TPMI), and the other signaling word is a PMI acknowledgement signaling word. Specifically, the first device may use the TPMI to indicate which codeword in the codebook specified in the protocol for LTE Rel-8 and subsequent evolution it uses on the bandwidth for transmitting the CSI-RS or the first DM-RS; the PMI acknowledgement signaling is then used to indicate which precoded codeword is used for data sent to the second UE.

Specifically, the number of bits of the TPMI is not less than the number of codewords in a codebook corresponding to the number of antenna ports through which the first device transmits data of the second UE, for example, 4 codewords are in a codebook corresponding to 2 antenna ports, so the TPMI can be 2 bits at minimum; the codebook corresponding to the 4-antenna port has 16 code words, so the TPMI can be 4 bits at minimum; there are 64 codewords in the codebook corresponding to 8 antenna ports, so the TPMI can be 8 bits at minimum; when there are more antenna ports to transmit data, for example, 32 antenna ports, the number of bits of the TPMI should be not less than the number of codewords in the codebook corresponding to the 32 antenna ports, for example, the TPMI may be 32 bits at minimum.

Further, the number of bits of the PMI confirmation signaling is not particularly limited as long as it can indicate which precoded codeword is used for data transmitted to the second UE. For example, PMI confirmation signaling may be represented using 1 bit, and if its value is 0, it represents that precoding is performed using a codeword indicated by TPMI; if the value is 1, it indicates that the PMI value reported to the first device at the latest one-pass aperiodic CSI is used. The last aperiodic CSI reporting interval value is different for different systems. FDD systems are 4 milliseconds and TDD systems are 4 milliseconds apart. In addition, the uplink and downlink configuration ratios are different, the interval values are also different, and specific values can be performed according to the relevant regulations of the LTE protocol TDD.

In a specific implementation, the signaling word may be a component of a certain signaling and sent by the first device to the second UE. Since the TPMI and PMI confirmation signaling words are used for data demodulation, the TPMI and PMI confirmation signaling words should be indicated with fast signaling, which may be DCI in LTE. In order to implement the above indication, a new DCI needs to be designed to carry the above precoding indication therein. It should be noted that the new DCI includes at least two signaling words, i.e., the TPMI and the PMI confirmation signaling. Of course, the TPMI and PMI acknowledgement signaling words may also be indicated with RRC signaling.

It should be noted that step S302 needs to be executed only when the first device does not precode data, that is, if the first device precodes data, the second UE may directly demodulate data with a demodulation reference signal sent by the first device, where the demodulation reference signal may be a second DM-RS, which will be described in detail in the following embodiments.

Step S303, the first device sends the first indication information to the second UE.

Specifically, when the second UE multiplexes the same physical resource block with other devices, that is, when there are not only the demodulation reference signal and data of the second UE but also the demodulation reference signal and data of other devices on the same physical resource block, the first device needs to send the first indication information to the second UE. It should be noted that the other device herein may be the first UE defined above, or may be the remaining second UE.

Further, the first indication information is used for indicating a position of the second UE for rate matching or interference measurement in the physical resource block. That is, the second UE may perform a rate matching or interference measurement operation according to the location indicated by the first indication information. In practice, whether rate matching or interference measurement is made at that location is determined by the first device scheduling.

Furthermore, if the physical resource block includes a location where at least one first UE sends the DM-RS, that is, there is at least one first UE and a second UE sharing the same physical resource block, at this time, the location indicated by the first indication information needs to include locations of all the DM-RSs of the first UE in the physical resource block. The second UE needs to perform rate matching or interference measurement at the locations of the DM-RSs of all the first UEs indicated by the first indication information.

Furthermore, since the CSI-RS or the first DM-RS may be configured to demodulate data of two or more second UEs, if the physical resource block includes at least one demodulation reference signal and data of a second UE, the location indicated by the first indication information needs to include locations of demodulation reference signals sent to other second UEs except the second UE in the two or more second UEs on the physical resource block, that is, the second UE needs to perform rate matching or interference measurement on locations of demodulation reference signals of the other second UEs indicated by the first indication information.

Specifically to the implementation, when the demodulation reference signal is a CSI-RS or a first DM-RS, the first indication information may be zero-power CSI-RS signaling in an existing protocol. Actually, the UE is informed by the upper RRC signaling, and the current CSI-RS configuration information is specifically either one of the two. It should be noted that, the order of steps S301, S302, and S303 is not limited herein, that is, in practice, the execution order of the three steps may be flexibly adjusted. In addition, the configuration information, the first indication information and the second indication information may be sent through one signaling, or may be sent in two or three signaling.

Step S304, the first device sends the CSI-RS at the position of sending the CSI-RS in the physical resource block, or the first device sends the first DM-RS at the position of sending the first DM-RS in the physical resource block.

Specifically, after the first device determines the location of the CSI-RS or the first DM-RS to be sent to the second UE and sends the related signaling to the second UE, the CSI-RS or the first DM-RS may be sent to the second UE.

It should be noted that, in general, since the CSI-RS or the first DM-RS is used for data demodulation, the first device may send a signaling first and then send the CSI-RS or the first DM-RS, but it is only limited that steps S300 and S304 need to be executed sequentially here, and the order of sending the signaling and the CSI-RS or the first DM-RS is not strictly limited.

In addition, optionally, the first device may further send a third indication signaling to the base station, where the base station refers to a device having a base station transmission function and does not refer to an existing base station specifically. Specifically, the third indication signaling is used to indicate a location of the CSI-RS or the first DM-RS of the second UE in the physical resource block, so that the base station reserves the location of the CSI-RS or the first DM-RS of the second UE in the physical resource block. For example, to limit and reduce co-channel interference between multiple cells, the first device may send information of resource locations occupied by the CSI-RS or the first DM-RS sent to the second UE to an adjacent cell or a transmitter, that is, a base station, so that the adjacent cell or the transmitter vacates the corresponding resource locations to protect the CSI-RS or the first DM-RS sent by the first device.

Step S305, the second UE receives the configuration information sent by the first device.

Specifically, since the first device sends configuration information to the second UE, the second UE needs to receive the configuration information and determine the location of the CSI-RS or the first DM-RS in the physical resource block according to the configuration information.

Step S306, the second UE receives the precoding indication sent by the first device.

Specifically, since the first device sends the precoding indication to the second UE, the second UE needs to receive the precoding indication and obtain precoding information of data of the second UE according to the precoding indication.

Step S307, the second UE receives the first indication information sent by the first device.

Specifically, since the first device sends the first indication information to the second UE, the second UE needs to receive the first indication information and perform rate matching or interference measurement according to the position in the physical resource block indicated by the first indication information.

In practice, the first indication information may be carried by CSI-RS signaling with zero power.

Step S308, the second UE carries out rate matching or interference measurement according to the position in the physical resource block indicated by the first indication information.

Specifically, after receiving the first indication information, the second UE may perform rate matching or interference measurement according to the position in the physical resource block indicated by the signaling.

It should be noted that, similar to the sequence of steps S301, S302, and S303, the sequence of step S306, step S307, and step S308 is not limited herein. The ordering of the second UE performing the above three steps may or may not correspond to the order of the first device. In practice, the transmission order of the first device and the reception order of the second UE may be flexibly adjusted as needed.

Step S309, the second UE receives the CSI-RS sent by the first device at the position where the CSI-RS is sent in the physical resource block, or the second UE receives the first DM-RS sent by the first device at the position where the first DM-RS is sent in the physical resource block.

Specifically, since the first device sends the CSI-RS or the first DM-RS to the second UE, the second UE needs to receive the CSI-RS or the first DM-RS. Specifically, the second UE needs to receive the CSI-RS or the first DM-RS at the location of the CSI-RS or the first DM-RS indicated by the configuration information in the physical resource block.

And S310, the second UE demodulates the user data according to the CSI-RS or the first DM-RS and the precoding information.

Specifically, since the demodulation reference signal sent by the first device to the second UE is the CSI-RS or the first DM-RS, that is, the reference signal that is not precoded, the second UE needs to combine the CSI-RS or the first DM-RS with the precoding information indicated by the precoding indication to demodulate the user data, that is, demodulate the data of the second UE.

It should be noted that, since the first device sends signaling first and then sends the CSI-RS or the first DM-RS, the second UE receives signaling first and then receives the CSI-RS or the first DM-RS. In practice, the transmission order of the first device is not fixed, and therefore, the receiving order of the second UE is not strictly limited.

For more clear description of the above scheme, the following describes how the first base station determines the position of transmitting the CSI-RS or the first DM-RS according to different CSI-RS position mapping manners in table 1 in detail with reference to the resource occupation pattern on the PRB pair in fig. 1, so as to flexibly support more user demodulation.

FIG. 5 is a resource map of CSI-RS of a 4-antenna port in one PRB pair under a normal cyclic prefix of LTE Rel-10. The meanings of RE in different patterns in fig. 5 are the same as those in fig. 1, and are not described herein again.

Specifically, the first device may transmit a demodulation reference signal, i.e., a CSI-RS or a first DM-RS, according to the CSI-RS mapping position shown in fig. 5. As shown in fig. 5, at this time, the CSI-RS occupies 4 REs in one PRB pair, i.e. the cross-striped REs in the figure, that is, the first device may transmit the CSI-RS or the first DM-RS at the positions of the above-mentioned 4 REs. The above-mentioned positions of the 4 REs may be mapping positions that the first device has used or unused or has used plus unused CSI-RS.

Further, the first device may notify the second UE of the locations of the 4 REs by using non-zero power CSI-RS signaling. Specifically referring to fig. 5, taking the CSI-RS configuration number and the number of the transmitted antenna ports as an example, according to table 1, the first device may configure the number of the antenna ports for transmitting the CSI-RS as 4, and configure the CSI-RS configuration number as 0, that is, may indicate the location mapping manner of the CSI-RS of the 4 antenna ports. It should be noted that, in practice, related parameters in table 2 need to be configured to indicate the subframe number for transmitting the CSI-RS, and the configuration method is the same as the description of table 2. The following embodiments only briefly describe the CSI-RS configuration number configuration and the number of transmitted antenna ports when the CSI-RS is mapped at different positions in the physical resource block, and details about the configuration of table 2 are not repeated.

Furthermore, since the number of REs occupied by the demodulation reference signal required for demodulating one data stream is different, that is, the number of REs required for demodulating data of one data stream is different, the 4 REs occupied by the CSI-RSs of the 4 antenna ports may be allocated differently.

Specifically, if data demodulation of one data stream requires the number of REs corresponding to 2 CSI-RS antenna ports, that is, 2 REs, the first device may simultaneously support data demodulation of 2 data streams at maximum; if the data demodulation of one data stream requires averaging the number of REs corresponding to 1 CSI-RS antenna port, that is, 1 RE, the first device may support data demodulation of 4 data streams at the same time. The following takes an example that data demodulation of one data stream requires the number of REs corresponding to 2 CSI-RS antenna ports as a further description. Specifically, to the number of users, the first device may determine how to allocate the 2 data streams according to the number of second UEs that need to be supported actually and the number of data streams that each second UE needs. For example, the first device may support a second UE with 2 data streams using the 4 REs; the first device may also support two second UEs with two data streams of number 1.

It should be noted that the 4 antenna ports are CSI-RS antenna ports for transmitting CSI-RS, and the mapping relationship between the antenna ports for transmitting CSI-RS from the first device and the physical antenna ports of the first device is not limited herein. In practice, the first device may virtualize a plurality of physical antenna ports as one antenna port for transmitting CSI-RS when implemented. The virtual mode may be to dynamically select one of the plurality of physical antenna ports, or to generate one antenna port for transmitting CSI-RS by precoding the plurality of physical antenna ports.

In addition, the first device may also determine a location in the physical resource block to transmit the CSI-RS or the first DM-RS according to channel state information of the second UE. That is, for a second UE in a different environment, the first device may use CSI-RS of other configurations for transmitting CSI-RS or the first DM-RS than the CSI-RS occupancy location in fig. 5.

Specifically, since each 2 immediately adjacent REs in the 4 cross-striped REs shown in fig. 5 are taken as a group, and the two groups of REs are both located on the same OFDM symbol in the time domain, the position where the CSI-RS or the first DM-RS is transmitted shown in fig. 5 is relatively stable in time, and thus is more suitable for a scenario where the frequency domain selectivity of the channel of the second UE is strong. Of course, the first device may also select another CSI-RS location mapping manner, so that the demodulation reference signals sent to the second UE can be staggered in the time domain and the frequency domain.

Fig. 6 is a resource map of CSI-RS of two configured 2-antenna ports in one PRB pair under the normal cyclic prefix of LTE Rel-10. The meanings of RE in different patterns in fig. 6 are the same as those in fig. 1, and are not described herein again. As shown in fig. 6, the difference between the two cross-stripe REs in fig. 6 and fig. 5 is that, at this time, the 4 cross-stripe REs in fig. 6 may correspond to the position mapping manner of CSI-RS at two 2 antenna ports in table 1.

Specifically, according to table 1, the first device may configure the number of antenna ports for transmitting CSI-RS as 2, and configure the CSI-RS configuration numbers as 0 and 19, that is, may indicate the location mapping manner of CSI-RS of the two 2 antenna ports.

Further, when the first device transmits the CSI-RS or the first DM-RS according to the CSI-RS mapping position shown in fig. 6, as described above with reference to fig. 5, the first device may simultaneously support data demodulation of 2 or 4 data streams at maximum according to the difference of the number of REs required for data demodulation of each data stream. How to allocate the 2 data streams is the same as the description of fig. 5, and is not described again here.

In addition, the first device may also transmit the CSI-RS or the first DM-RS at more CSI-RS mapping locations according to the number of data streams that actually need to be supported, which is described below with reference to fig. 7.

FIG. 7 is a resource map of CSI-RS of a next 8-antenna port in one PRB pair under a normal cyclic prefix of LTE Rel-10. The meanings of RE in different patterns in fig. 7 are the same as those in fig. 1, and are not described herein again. As shown in fig. 7, at this time, the 8 cross-striped REs in fig. 7 may correspond to the position mapping manner of the CSI-RS when two 4-antenna ports are shown in table 1.

Specifically, according to table 1, the first device may configure the number of antenna ports for transmitting CSI-RS as 4, and configure the CSI-RS configuration numbers as 0 and 9, that is, may indicate the location mapping manner of CSI-RS of the two 4 antenna ports.

Further, when the first device transmits the CSI-RS or the first DM-RS according to the CSI-RS mapping position shown in fig. 7, as described above with reference to fig. 5, the first device may simultaneously support data demodulation of 2 or 4 or 8 data streams at maximum according to the difference of the number of REs required for data demodulation of each data stream. Taking data demodulation that the first device can simultaneously support 8 data streams at maximum as an example, specifically, for the number of users, the first device may determine how to allocate the 8 data streams according to the number of second UEs that need to be supported actually and the number of data streams that each second UE needs. For example, the first device may support a second UE with 8 data streams using the 8 REs; the first device may also support two second UEs with two data streams of 4; the first device may also support four second UEs with a data stream number of 2.

It should be noted that, since the UEs on different bandwidths perform transmission in a frequency division multiplexing manner, when the first device sends the CSI-RS on the full bandwidth, the first device may configure the same CSI-RS for the UEs on different bandwidths to perform demodulation, or configure different CSI-RSs to perform demodulation.

Of course, various other configurations may be used, not listed here. However, no matter what method is used, when the first device sends the CSI-RS or the first DM-RS using the CSI-RS mapping location, it only needs to send the configuration information of the CSI-RS for implementing data demodulation to the second UE through the configuration information, that is, step S301, and thus, data demodulation of more data streams can be implemented, thereby supporting more UEs. More is supported here, including both the previously described data demodulation of the second UE with CSI-RS over different bandwidths, and MU-MIMO of the second UE with the first UE. How the first device implements MU-MIMO of the second UE with the first UE is described in detail below in conjunction with fig. 8.

Fig. 8 is a resource map in MU-MIMO in which one second user equipment performs space division multiplexing with a first user equipment. The meanings of RE in different patterns in fig. 8 are the same as those in fig. 1, and are not described herein again. It should be noted that, the number of the first UEs is not limited here, and the positive 45 ° diagonal line RE in the left graph and the negative 45 ° multiple diagonal lines RE in the right graph in the figure are resource locations of the DM-RS that are most likely to be occupied by all the first UEs.

Specifically, the cross-striped REs in the left graph of fig. 8 indicate mapping positions of CSI-RSs used by the first UE, and these CSI-RSs may be non-zero power CSI-RSs or zero power CSI-RSs, and it is not limited which CSI-RSs are specifically used by each first UE, and the position mapping manner is the same as that in the prior art. In contrast, the cross-striped REs in the right graph of fig. 8 represent the mapping positions of the CSI-RS or the first DM-RS used by the second UE for data demodulation, and it can be seen that, in the same physical resource block, the second UE does not need to use the DM-RS position of the existing device for data demodulation, but occupies the mapping position of the CSI-RS of the first UE, so that MU-MIMO between the second UE and the first UE is achieved.

Further, in order to avoid interference to the first UE, the second UE needs to send no data on the port of the DM-RS of the existing device, i.e. perform rate matching, i.e. the position of the DM-RS of the first UE is indicated by negative 45 ° diagonal lines RE in the right graph of fig. 8. Of course, the situation is given here when the first UE occupies all the DM-RS available resources, and in practice, the second UE only needs to perform rate matching at the resource location of the DM-RS actually occupied by the existing device. In addition, the first device needs to use the first indication information to indicate to the second UE at which positions to perform rate matching according to the description of step S303.

It should be noted that fig. 8 does not limit the number of the second UEs, because fig. 8 is the same as fig. 7, at this time, 8 REs may correspond to a location mapping manner of CSI-RS at 8 antenna ports, or may correspond to location mapping manners of CSI-RS at two 4 antenna ports, as also described above for fig. 5, according to the difference of the number of REs required for data demodulation of each data stream, the above 8 REs may simultaneously support data demodulation of 2, 4, or 8 data streams at maximum, and how to allocate the above 8 data streams is taken as an example that the maximum support of 8 data streams, which is the same as the description for fig. 7, and is not repeated herein. That is, the first device may configure a plurality of different second UEs to use different CSI-RSs, thereby implementing space division multiplexing for MU-MIMO with the first UE on the same time-frequency resources.

As can be seen from fig. 8, the DM-RS of the first UE supports 8 data streams at the maximum simultaneously, and the 8 cross-striped REs occupied by the second UE can also support 8 data streams at the maximum simultaneously, so that the first device can support data demodulation of 16 data streams at the maximum simultaneously, which doubles the spatial multiplexing MU-MIMO capability of the first device compared to the prior art.

The transmission method for the demodulation reference signal according to the embodiment does not need to design a new DM-RS resource mapping manner for the second UE, and does not need to occupy the DM-RS position of the first UE, and only needs to determine, by the first device, the demodulation reference signal, that is, the CSI-RS or the first DM-RS, to be sent at the mapping position of the used or unused CSI-RS in the physical resource block, and notify the second UE of the position of the demodulation reference signal by using the existing signaling, so that the second UE can complete data demodulation.

Fig. 9 is an interaction flowchart of a first device and a second user equipment according to a fourth embodiment of the present invention. This embodiment describes in detail a specific interaction process between the first device and the second user equipment, that is, the second UE, when the demodulation reference signal sent by the first device is the second DM-RS. As shown in fig. 9, the method for transmitting demodulation reference signals according to this embodiment may include the following steps:

step S400, the first device determines the position of sending the second DM-RS in the physical resource block.

Specifically, the first device may determine a location at which the second DM-RS is transmitted. The above-mentioned position for transmitting the second DM-RS includes a mapping position of used, unused, or used plus unused CSI-RS. The mapping position of the CSI-RS is a position set of all REs used for placing the CSI-RS in a physical resource block defined in the long term evolution LTE system release Rel-10. Specifically, fig. 1 is a resource location composed of all cross-striped REs.

As a first case, when the position to transmit the second DM-RS is a CSI-RS mapping position already used by the first device, the first device determines that the position to transmit the second DM-RS to the second UE is the same as the mapping position of the CSI-RS it transmits to the first UE. Specifically, the first device may send the second DM-RS at the mapping position of the CSI-RS of the first UE, and certainly, since the mapping position of the CSI-RS is already used to place the CSI-RS of the first UE, and then the second DM-RS is sent at the same position to the second UE, interference may be generated, so that this implementation may be used as a suboptimal solution. In this case, in general, the first device does not need to configure a new mapping position of the CSI-RS for the second UE, but only needs to notify the second UE to perform data demodulation on the mapping position of the CSI-RS of the existing device.

As a second case, when the position to transmit the second DM-RS is a mapping position of a CSI-RS that is not used by the first device, the first device determines the position to transmit the second DM-RS to the second UE as a mapping position of a CSI-RS remaining after the mapping positions of all available CSI-RSs of the first device are subtracted by the mapping positions of CSI-RSs that have been used to transmit the first UE. Specifically, since the first device does not use the position to transmit the second DM-RS at this time, the first device may transmit the second DM-RS at an unused CSI-RS mapping position as a demodulation reference signal. Unlike the case where the first device transmits the DM-RS as the demodulation reference signal at the mapping position of the already-used CSI-RS, the first device does not multiplex the mapping position of the already-used CSI-RS at this time, but transmits the demodulation reference signal using the mapping position of the new CSI-RS.

As a third case, when the position to transmit the second DM-RS is the mapping position that the first device has used plus the unused CSI-RS, the first device determines the position to transmit the second DM-RS to the second UE to be the sum of the mapping positions that the first device has used plus the unused CSI-RS. Specifically, when the positions for sending the second DM-RS are already used, the specific implementation manner is the same as the description of the first case, and when the positions for sending the second DM-RS are not used, the specific implementation manner is the same as the description of the second case, and is not described again here.

It should be noted that, different from step S300, the second DM-RS is only transmitted at the position where the second DM-RS is transmitted, but the specific position mapping manner of the second DM-RS is different from the position mapping manner of the CSI-RS, and the second DM-RS is precoded by the first device, so that the first device does not need to transmit precoding indication information to the second UE, and the second UE can perform data demodulation according to the second DM-RS. In addition, the first device may not precode the second DM-RS, that is, step S402 is not performed, and except that step S409 is the same as step S310, the other steps are also applicable to the second DM-RS that is not precoded, and of course, if the first device does not precode the second DM-RS, it is necessary to send a precoding indication before S404 and receive the precoding indication after S405 as described in embodiment two, and the specific process thereof is the same as the sending and receiving precoding indications in the previous embodiment, and details are not repeated here.

In actual use, different location mapping sets may be configured for the second DM-RS in advance, for example, the available location of the second DM-RS may be determined in advance by referring to the CSI-RS configuration manners in tables 1 and 2, at this time, the first device needs to indicate, for the second UE, a specific RE location for sending the second DM-RS and the location mapping set of the second DM-RS.

It should be noted that the bandwidth of the first device for transmitting the second DM-RS is only required to be not less than the bandwidth of the second UE for transmitting data. The first device may select a corresponding density of REs for the second UE to transmit the second DM-RS according to actual channel conditions of the second UE.

Step S401, the first device sends configuration information to the second UE, wherein the configuration information is used for indicating the position of the second DM-RS in the physical resource block.

Specifically, after determining that the position of the second DM-RS in the physical resource block sends the demodulation reference signal to the second UE, the first device needs to send configuration information to the second UE to indicate the position of the second DM-RS in the physical resource block.

Since the location mapping set of the second DM-RS is newly defined, new signaling needs to be designed as configuration information. For example, the second UE may be informed of the position of the demodulation reference signal in the physical resource block by referring to the design format of the non-zero power CSI-RS signaling in step S301, that is, the parameters shown in table 1 and table 2, through the configuration number of the second DM-RS, the number of antenna port configurations, the subframe configuration, the transmission period, the subframe offset, and the like. Optionally, the first device may place the configuration Information in Downlink Control Information (DCI), and then send the configuration Information to the second UE to indicate a position of the demodulation reference signal in a physical resource block. Of course, considering that there are many signaling words corresponding to the configuration information, the first device may also use Radio Resource Control (RRC) signaling to indicate to the second UE, and when indicating, the first device needs to explicitly specify that the mapping position of the CSI-RS indicated by the configuration information is used for data demodulation of the second UE.

It should be noted that, according to the description in step S201, for the first DM-RS, the first device further needs to issue a p-C value for the second UE, except that for the second DM-RS, the p-C value may be fixed in a protocol manner, so that no additional signaling is needed to indicate.

Step S402, the first device carries out precoding on the second DM-RS.

Specifically, the first device may precode the second DM-RS, so that the second UE may complete data demodulation according to the second DM-RS. Here, the precoding manner of the second DM-RS is the same as the precoding manner of the DM-RS of the first UE in the prior art, and is not described herein again.

Step S403, the first device sends the first indication information to the second UE.

The specific description of this step is the same as step S303, except that, since the second DM-RS is not mapped in the physical resource block according to the position mapping manner of the CSI-RS, the first indication information here cannot be realized by the CSI-RS signaling with zero power, but in practice, the first indication information may be designed by borrowing the format of the CSI-RS signaling with zero power.

It should be noted that, the order of steps S401, S402, and S403 is not limited here, that is, in practice, the execution order of the three steps may be flexibly adjusted.

And S404, the first device sends the second DM-RS at the position of sending the second DM-RS in the physical resource block.

Specifically, after the first device determines the location of the second DM-RS to be sent to the second UE, that is, the location of the second DM-RS to be sent, and sends the related signaling to the second UE, the second DM-RS may be sent to the second UE.

It should be noted that, in general, since the second DM-RS is used for data demodulation, the first device may send the signaling first and then send the second DM-RS, but it is only limited that steps S400 and S404 need to be executed successively here, and no strict limitation is made as to the sending of the signaling and the second DM-RS.

In addition, optionally, the first device may further send a third indication signaling to the base station, where the base station refers to a device having a base station transmission function and does not refer to an existing base station specifically. Specifically, the third indication signaling is used to indicate a location of the second DM-RS of the second UE in the physical resource block, so that the base station reserves the location of the second DM-RS of the second UE in the physical resource block. For example, to limit and reduce co-channel interference between multiple cells, the first device may send information of resource locations occupied by the second DM-RS of the second UE to an adjacent cell or transmitter, that is, a base station, so that the adjacent cell or transmitter vacates the corresponding resource locations to protect the second DM-RS sent by the first device.

Step S405, the second UE receives the configuration information sent by the first device.

Step S406, the second UE receives the first indication information sent by the first device.

Step S407, the second UE performs rate matching or interference measurement according to the position in the physical resource block indicated by the first indication information.

Step S408, the second UE receives the second DM-RS sent by the first device at the position where the second DM-RS is sent in the physical resource block.

The above step S405 is the same as the description of step S305, and steps S406 to S408 are the same as steps S307 to S309, except that the CSI-RS or the first DM-RS in steps S305, S307 to S309 needs to be replaced with the second DM-RS.

In addition, in practice, the first indication information may be carried by CSI-RS signaling with zero power.

And step S409, the second UE demodulates the user data according to the second DM-RS.

Specifically, since the demodulation reference signal of the second UE sent by the first device is the second DM-RS, which is a precoded reference signal, the second UE can perform user data demodulation according to the second DM-RS, that is, demodulation of data of the second UE.

It should also be noted that, since the first device sends signaling first and then sends the second DM-RS, the second UE receives signaling first and then receives the second DM-RS. In practice, the transmission order of the first device is not fixed, and therefore, the receiving order of the second UE is not strictly limited.

Since the second DM-RS is mapped only at the position where the second DM-RS is transmitted, the mapping is different from the CSI-RS. This difference is shown in that the CSI-RS is the same on all PRB pairs, and the second DM-RS may be the same or different on adjacent PRBs.

For more clearly describing the above scheme, a resource mapping diagram when multiple second UEs perform MU-MIMO is described in detail below with reference to the resource occupation pattern on the PRB pair in fig. 1.

Fig. 10 is a resource map in MU-MIMO in which two second user equipments space-multiplex in one PRB pair under a normal cyclic prefix. The meanings of RE in different patterns in fig. 10 are the same as those in fig. 1, and are not described herein again.

Specifically, as shown in fig. 10, where both UE1 and UE2 are the second UE, the cross-stripes in the figure indicate the RE positions occupied by their second DM-RS. From left to right, from top to bottom, the first graph is the RE position occupied by the second DM-RS of UE1, the second graph is the RE position occupied by the second DM-RS of UE2, and the third graph is the RE position occupied by both the second DM-RS of UE1 and UE 2.

Further, the resource mapping patterns of the second DM-RS on each PRB of the UE1 and the UE2 are the same, and although the RE positions occupied by the second DM-RS of the UE1 and the UE2 are different from the position mapping patterns of the CSI-RS, that is, no corresponding CSI-RS configuration number in table 1 corresponds to such an RE arrangement, the second DM-RS of the UE1 and the UE2 merge the occupied resources, that is, the third diagram from left to right and from top to bottom, at this time, the UE1 and the UE2 jointly occupy 16 REs, and the resources occupied by these 2 UEs may be represented by the position mapping patterns of the CSI-RS of 4 antenna ports. Specifically, in the configuration number in table 1, the number of antenna ports of the CSI-RS may be configured to be 4, and the CSI-RS configuration number may be configured to be: 0, 5, 4, and 9, which indicates the location mapping manner of the CSI-RS of the 4 antenna ports.

Furthermore, if only the two UEs are used in the first device, the RE positions of the CSI-RSs of the 4 antenna ports corresponding to the second DM-RSs of the two UEs only need to be indicated to the first UE by the CSI-RS with zero power.

Further, for UE1 and UE2, since they occupy 8 REs each, as described above with respect to fig. 5, the first device can simultaneously support data demodulation of 2 or 4 or 8 or 16 data streams at maximum according to the difference of the number of REs required for data demodulation of each data stream. Taking the number of REs required for data demodulation of each data stream as 2 as an example, that is, the maximum number of data streams is supported by 8, at this time, the first device can transmit a maximum of 4 data streams for UE1 and UE2, respectively.

In order to reduce the overhead of the second DM-RS, REs of the second DM-RS may be placed on PRBs adjacent in a time domain or a frequency domain in a sparse manner. Fig. 11 is a resource map of MU-MIMO in which four second user equipments space-multiplex in one PRB pair under a normal cyclic prefix. The meanings of RE represented by different patterns in FIG. 11 are the same as those in FIG. 1, and are not described herein again.

Specifically, as shown in fig. 11, wherein UE1, UE2, UE3, and UE4 are all second UEs, the cross-stripes in the figure indicate RE positions occupied by their second DM-RS. It can be seen that the RE positions occupied by the second DM-RS of the above four UEs taken together are the same as the RE positions occupied by the second DM-RS of the UE1 and the UE2 taken together in fig. 10, i.e. the third diagram from left to right and from top to bottom in fig. 10. In contrast, fig. 11 is equivalent to splitting the resource occupied by the second DM-RS of each second UE in fig. 10 to two second UEs, i.e., splitting the resource occupied by the second DM-RS of UE1 in fig. 10 into UE1 and UE2 in fig. 11, and splitting the resource occupied by the second DM-RS of UE2 in fig. 10 into UE3 and UE4 in fig. 11. Taking the number of REs required for data demodulation of each data stream as 2 as an example, the first device in fig. 11 can simultaneously support data demodulation of 8 data streams at maximum, and since there are four UEs at this time, the second DM-RS of each UE occupies 4 REs, each UE can transmit data of 2 data streams. Of course, each UE in fig. 11 may be further split into two UEs, and the method is similar to that in fig. 11 and is not described here again.

In addition, in order to protect each device doing MU-MIMO, it is necessary to perform rate matching in the region where the second DM-RS of the other devices except for itself is located, as shown in fig. 12. Fig. 12 is a diagram of rate matching in MU-MIMO in which four second user equipments space-multiplex in one PRB pair under a normal cyclic prefix. The meanings of RE in different patterns in fig. 12 are the same as those in fig. 1, and are not described herein again.

Specifically, the four second UEs, UE1, UE2, UE3 and UE4, not only need to perform rate matching at the position of the DM-RS of the first UE, but also need to perform rate matching at the positions of the second DM-RSs of the other second UEs except for the first UE.

From the third plot from left to right and from top to bottom of fig. 10, it can be seen that the plot is positive 45. And the RE of the diagonal line is the RE position occupied by the DM-RS of the first UE, and the RE of the cross stripe is the RE position occupied by the second DM-RS of the four second UEs. Still taking the number of REs required for data demodulation of each data stream as an example of 2, at this time, the second DM-RS serves as a demodulation reference signal, and can simultaneously support data demodulation of 8 data streams at most, and since the DM-RS of the first UE can support data demodulation of 8 data streams at most, at this time, the first device can simultaneously support MU-MIMO transmission of 16 data streams at most, which is equivalent to double the transmission capability of the space division multiplexing MU-MIMO.

It can be seen that the use of the second DM-RS does not bring any additional signaling and standardization impact to the first UE, and the first UE can still perform downlink data transmission and measurement after being configured according to the original protocol, so that complete backward compatibility is achieved when the UE introducing more MU-MIMO performs spatial multiplexing transmission.

Fig. 13 is an interaction flowchart of a first device and a first user equipment according to a fifth embodiment of the present invention. As shown in fig. 13, the method for transmitting demodulation reference signals according to this embodiment may include the following steps:

step S500, the first device sends second indication information to the first UE.

Specifically, when the second UE and the first UE reuse the same time-frequency resource, the first device needs to send the second indication information to the first UE.

Further, the second indication information is used to indicate a position of the demodulation reference signal of the second UE in the physical resource block, so that the first UE performs rate matching or interference measurement according to the position of the demodulation reference signal of the second UE in the physical resource block. The position indicated by the indication signaling only needs to include the positions of the demodulation reference signals occupied by all the second UEs. The demodulation reference signal may be a CSI-RS, or may also be a first DM-RS or a second DM-RS.

Still further, the second indication information may be carried by zero-power CSI-RS signaling.

Step S501, the first UE receives second indication information sent by the first device.

The main execution body of this step is the first UE, and in practice, this first UE may be the first UE.

Specifically, after the first device sends the second indication information to the first UE, the first UE needs to receive the second indication information.

Step S502, the first UE carries out rate matching or interference measurement according to the position of the demodulation reference signal of the second UE in the physical resource block.

Specifically, since the second indication information indicates the position of the demodulation reference signal of the second UE in the physical resource block, the first UE may perform rate matching or interference measurement according to the signaling. In practice, whether rate matching or interference measurement is made at that location is determined by the first device scheduling. The demodulation reference signal may be a CSI-RS, or may also be a first DM-RS or a second DM-RS.

By adopting the scheme of the embodiment, the first equipment actively informs the first UE to carry out rate matching or interference measurement, thereby realizing backward compatibility of the first UE.

Fig. 14 is a schematic structural diagram of a first device according to a sixth embodiment of the present invention. As shown in fig. 14, the first apparatus includes: a determination module 10 and a sending module 11.

Specifically, the determining module 10 is configured to determine a location where a demodulation reference signal is sent in a physical resource block, where the location where the demodulation reference signal is sent includes a mapping location of a channel state information reference signal CSI-RS that has been used and/or is not used by a first device, and the demodulation reference signal is used for demodulating data of a second user equipment; the sending module 11 is configured to send configuration information to the second user equipment, where the configuration information is used to indicate a position of a demodulation reference signal in a physical resource block.

Further, the sending module 11 is further configured to send the demodulation reference signal at a position in the physical resource block where the demodulation reference signal is sent.

Further, the configuration information is non-zero power CSI-RS signaling.

Further, the mapping position of the CSI-RS is a position set of all resource elements RE for placing the CSI-RS in the physical resource block defined in long term evolution LTE system release Rel-10.

Further, the determination module 10 is specifically configured to: and determining the position of sending the demodulation reference signal in the physical resource block according to the channel state information of the second user equipment.

Further, the sending module 11 is further configured to: and sending a precoding indication to the second user equipment, wherein the precoding indication is used for indicating precoding information of user data of the second user equipment so as to enable the second user equipment to demodulate the user data according to a demodulation reference signal and the precoding information, the demodulation reference signal comprises a CSI-RS used for performing channel measurement operation or a first downlink demodulation reference signal DM-RS used for performing user data demodulation, and the first DM-RS is the DM-RS which is mapped on a position where the demodulation reference signal is sent in a physical resource block according to a mapping mode of the CSI-RS.

Further, the precoding indication is sent by the first device through downlink control information DCI or radio resource control RRC signaling.

Further, the sending module 11 is further configured to: and sending first indication information to the second user equipment, wherein the first indication information is used for indicating the position of the second user equipment for carrying out rate matching or interference measurement in the physical resource block.

Further, the first indication information is carried by zero-power CSI-RS signaling.

Further, if the physical resource block includes a location for transmitting the DM-RS to the at least one first user equipment, the location indicated by the first indication information includes the location for transmitting the DM-RS to the at least one first user equipment.

Further, if the demodulation reference signal is used for demodulating data of two or more second user equipments, the position indicated by the first indication information includes a position of the demodulation reference signal sent to the second user equipment other than the second user equipment in the two or more second user equipments on a physical resource block.

Further, the sending module 11 is further configured to: and sending second indication information to the at least one first user equipment, wherein the second indication information is used for indicating the position of the second user equipment for sending the demodulation reference signal, so that the at least one first user equipment carries out rate matching or interference measurement according to the position of the second user equipment for sending the demodulation reference signal.

Further, the second indication information is carried by zero-power CSI-RS signaling.

Further, the sending module 11 is further configured to: and sending a third indication signaling to the base station, wherein the third indication signaling is used for indicating the position of the second user equipment for sending the demodulation reference signal, so that the base station reserves the position of the second user equipment for sending the demodulation reference signal.

Still further, the determination module 10 is further configured to: and determining a physical resource block for transmitting the demodulation reference signal on a full bandwidth corresponding to the first equipment, or determining a physical resource block for transmitting the demodulation reference signal on a dedicated bandwidth of the second user equipment.

Fig. 15 is a schematic structural diagram of a first device according to a seventh embodiment. As shown in fig. 15, the first apparatus includes: a determination module 10, a transmission module 11 and an encoding module 20. The determining module 10 and the sending module 11 are the same as those in the sixth embodiment, and are not described herein again.

Specifically, the encoding module 20 is configured to precode a demodulation reference signal, where the demodulation reference signal is specifically a second DM-RS used for performing user data demodulation, and the second DM-RS is a DM-RS mapped in a preset mapping manner on a position where the demodulation reference signal is sent in a physical resource block.

Fig. 16 is a schematic structural diagram of a second apparatus provided in the eighth embodiment. As shown in fig. 16, the second apparatus includes: a receiving module 30 and a determining module 31.

Specifically, the receiving module 30 is configured to receive configuration information sent by the first device, where the configuration information is used to indicate a position of a demodulation reference signal in a physical resource block; the determining module 31 is configured to determine a position of the demodulation reference signal in the physical resource block according to the configuration information received by the receiving module 30; the receiving module 30 is further configured to receive the demodulation reference signal sent by the first device at the position of the demodulation reference signal in the physical resource block determined by the determining module 31, where the position of the demodulation reference signal in the physical resource block determined by the determining module 31 includes the mapping position of the CSI-RS already used and/or unused by the first device, and the demodulation reference signal is used for demodulating data of the second user equipment.

Further, the configuration information is non-zero power CSI-RS signaling.

Further, the receiving module 30 is further configured to: receiving a precoding indication sent by first equipment; acquiring precoding information of user data of second user equipment according to the precoding indication; the demodulation reference signal comprises a CSI-RS used for executing channel measurement operation or a first downlink demodulation reference signal DM-RS used for executing user data demodulation, and the first DM-RS is a DM-RS mapped on a position where the demodulation reference signal is sent in a physical resource block according to a mapping mode of the CSI-RS.

Further, the receiving module 30 is further configured to: receiving first indication information sent by first equipment, wherein the first indication information is used for indicating the position of second user equipment for carrying out rate matching or interference measurement in a physical resource block; and performing rate matching or interference measurement according to the position in the physical resource block indicated by the first indication information.

Fig. 17 is a schematic structural diagram of a second apparatus provided in the ninth embodiment. As shown in fig. 17, the second apparatus includes: a receiving module 30, a determining module 31 and a demodulating module 41. The receiving module 30 and the determining module 31 are the same as those in the eighth embodiment, and are not described again here.

Specifically, the demodulation module 41 is configured to demodulate user data according to the demodulation reference signal and the precoding information; the demodulation reference signal comprises a CSI-RS used for executing channel measurement operation or a first downlink demodulation reference signal DM-RS used for executing user data demodulation, and the first DM-RS is a DM-RS mapped on a position where the demodulation reference signal is sent in a physical resource block according to a mapping mode of the CSI-RS.

Fig. 18 is a schematic structural diagram of a first apparatus provided in this embodiment. As shown in fig. 18, the first apparatus includes: a processor 50 and a transmitter 51.

Specifically, the processor 50 is configured to determine a location in the physical resource block to send a demodulation reference signal, where the location to send the demodulation reference signal includes a mapping location of a channel state information reference signal CSI-RS that has been used and/or is not used by the first device, and the demodulation reference signal is used to demodulate data of the second user equipment; the transmitter 51 is configured to transmit configuration information to the second user equipment, where the configuration information is used to indicate a position of a demodulation reference signal in a physical resource block; the transmitter 51 is also configured to transmit the demodulation reference signal at a position in the physical resource block where the demodulation reference signal is transmitted.

Further, the configuration information is non-zero power CSI-RS signaling.

Further, the processor 50 is specifically configured to: and determining the position of sending the demodulation reference signal in the physical resource block according to the channel state information of the second user equipment.

Further, the transmitter 51 is also configured to: and sending a precoding indication to the second user equipment, wherein the precoding indication is used for indicating precoding information of user data of the second user equipment so as to enable the second user equipment to demodulate the user data according to a demodulation reference signal and the precoding information, the demodulation reference signal comprises a CSI-RS used for performing channel measurement operation or a first downlink demodulation reference signal DM-RS used for performing user data demodulation, and the first DM-RS is the DM-RS which is mapped on a position where the demodulation reference signal is sent in a physical resource block according to a mapping mode of the CSI-RS.

Still further, the processor 50 is further configured to: and precoding a demodulation reference signal, wherein the demodulation reference signal is specifically a second DM-RS used for executing user data demodulation, and the second DM-RS is a DM-RS mapped on a position where the demodulation reference signal is sent in a physical resource block according to a preset mapping mode.

Further, the transmitter 51 is also configured to: and sending first indication information to the second user equipment, wherein the first indication information is used for indicating the position of the second user equipment for carrying out rate matching or interference measurement in the physical resource block.

Further, the transmitter 51 is also configured to: and sending second indication information to the at least one first user equipment, wherein the second indication information is used for indicating the position of the second user equipment for sending the demodulation reference signal, so that the at least one first user equipment carries out rate matching or interference measurement according to the position of the second user equipment for sending the demodulation reference signal.

Further, the transmitter 51 is also configured to: and sending a third indication signaling to the base station, wherein the third indication signaling is used for indicating the position of the second user equipment for sending the demodulation reference signal, so that the base station reserves the position of the second user equipment for sending the demodulation reference signal.

Still further, the processor 50 is further configured to: and determining a physical resource block for transmitting the demodulation reference signal on a full bandwidth corresponding to the first equipment, or determining a physical resource block for transmitting the demodulation reference signal on a dedicated bandwidth of the second user equipment.

Fig. 19 is a schematic structural diagram of a second apparatus provided in the eleventh embodiment. As shown in fig. 19, the second apparatus includes: a receiver 60 and a processor 61.

Specifically, the receiver 60 is configured to receive configuration information sent by the first device, where the configuration information is used to indicate a position of a demodulation reference signal in a physical resource block; further, the processor 61 is configured to determine a position of the demodulation reference signal in the physical resource block according to the configuration information received by the receiver 60; the receiver 60 is further configured to receive the demodulation reference signal sent by the first device at a position in the physical resource block of the demodulation reference signal determined by the processor 61, where the position in the physical resource block of the demodulation reference signal determined by the processor 61 includes a mapping position of CSI-RSs already used and/or unused by the first device, and the demodulation reference signal is used for demodulating data of the second user equipment.

Further, the configuration information is non-zero power CSI-RS signaling.

Further, the receiver 60 is also configured to: receiving a precoding indication sent by first equipment; acquiring precoding information of user data of second user equipment according to the precoding indication; the processor 61 is further configured to demodulate user data according to the demodulation reference signal and the precoding information; the demodulation reference signal comprises a CSI-RS used for executing channel measurement operation or a first downlink demodulation reference signal DM-RS used for executing user data demodulation, and the first DM-RS is a DM-RS mapped on a position where the demodulation reference signal is sent in a physical resource block according to a mapping mode of the CSI-RS.

Furthermore, the demodulation reference signal is a precoded second DM-RS for performing user data demodulation, and the second DM-RS is a DM-RS mapped on a position where the demodulation reference signal is sent in the physical resource block according to a preset mapping manner.

Further, the receiver 60 is also configured to: receiving first indication information sent by first equipment, wherein the first indication information is used for indicating the position of second user equipment for carrying out rate matching or interference measurement in a physical resource block; and performing rate matching or interference measurement according to the position in the physical resource block indicated by the first indication information.

Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for transmitting a demodulation reference signal, comprising:

the method comprises the steps that a first device determines a position for sending a demodulation reference signal in a physical resource block, wherein the position for sending the demodulation reference signal comprises a mapping position of a channel state information reference signal (CSI-RS) which is used and/or unused by the first device, and the demodulation reference signal is used for demodulating data of a second user device;

2. The method of claim 1, wherein the configuration information is non-zero power CSI-RS signaling.

3. The method according to claim 1 or 2, wherein the mapping positions of the CSI-RS are a set of positions of all Resource Elements (REs) in the physical resource block defined in LTE Long Term Evolution (LTE) system release Rel-10 for placing the CSI-RS.

4. The method according to any one of claims 1 to 3, wherein the determining, by the first device, the position where the demodulation reference signal is transmitted in the physical resource block specifically includes:

5. The method according to any of claims 1-4, wherein the first device further comprises, before transmitting the demodulation reference signal at the position of the physical resource block where the demodulation reference signal is transmitted:

6. The method of claim 5, wherein the precoding indication is sent by the first device through Downlink Control Information (DCI) or Radio Resource Control (RRC) signaling.

7. The method according to any of claims 1-4, wherein the first device further comprises, before transmitting the demodulation reference signal at the position of the physical resource block where the demodulation reference signal is transmitted:

8. The method according to any one of claims 1 to 7, wherein before the first device transmits the demodulation reference signal at the position of the physical resource block where the demodulation reference signal is transmitted, the method further comprises:

9. The method of claim 8, wherein the first indication information is carried by zero-power CSI-RS signaling.

10. The method according to claim 8 or 9, wherein if the physical resource block includes a location for transmitting DM-RS to at least one first user equipment, the location indicated by the first indication information includes the location for transmitting DM-RS to the at least one first user equipment.

11. The method according to any of claims 8-10, wherein if the demodulation reference signal is used for demodulating data of two or more second user equipments, the location indicated by the first indication information comprises a location of a demodulation reference signal sent on the physical resource block to a second user equipment other than the second user equipment.

12. The method of claim 10, further comprising, before the first device transmits the demodulation reference signal at the position of the physical resource block where the demodulation reference signal is transmitted:

the first device sends second indication information to the at least one first user equipment, wherein the second indication information is used for indicating the position of the second user equipment for sending the demodulation reference signal, so that the at least one first user equipment carries out rate matching or interference measurement according to the position of the second user equipment for sending the demodulation reference signal.

13. The method of claim 12, wherein the second indication information is carried by zero-power CSI-RS signaling.

14. The method according to any of claims 1-13, further comprising, after the first device transmits the demodulation reference signal at the position of the physical resource block where the demodulation reference signal is transmitted, the step of:

the first device sends a third indication signaling to a base station, where the third indication signaling is used to indicate a position where the second user equipment sends a demodulation reference signal, so that the base station reserves the position of the demodulation reference signal of the second user equipment in the physical resource block.

15. The method according to any of claims 1-14, wherein the first device further comprises, before transmitting the demodulation reference signal at the position of the physical resource block where the demodulation reference signal is transmitted:

and the first device determines a physical resource block for sending the demodulation reference signal on a full bandwidth corresponding to the first device, or determines a physical resource block for sending the demodulation reference signal on a dedicated bandwidth of the second user equipment.

16. A method for transmitting a demodulation reference signal, comprising:

the second user equipment receives configuration information sent by the first equipment, wherein the configuration information is used for indicating the position of the demodulation reference signal in a physical resource block;

17. The method of claim 16, wherein the configuration information is non-zero power CSI-RS signaling.

18. The method according to claim 16 or 17, wherein the mapping positions of the CSI-RS are a set of positions of all resource elements, REs, in the physical resource block defined in long term evolution, LTE, system release Rel-10 for placing the CSI-RS.

19. The method according to any of claims 16-18, wherein before the second ue receives the demodulation reference signal sent by the first ue at the position indicated by the configuration information in the physical resource block, the method further comprises:

20. The method of claim 19, wherein the precoding indication is sent by the first device through Downlink Control Information (DCI) or Radio Resource Control (RRC) signaling.

21. The method according to any of claims 16-18, wherein the demodulation reference signal is a second DM-RS used for performing user data demodulation after being precoded, and the second DM-RS is a DM-RS mapped on the position of the physical resource block where the demodulation reference signal is sent according to a preset mapping manner.

22. The method according to any of claims 16-21, wherein before the second ue receives the demodulation reference signal sent by the first ue at the position indicated by the configuration information in the physical resource block, the method further comprises:

23. The method of claim 22, wherein the first indication information is carried by zero-power CSI-RS signaling.

24. A first device, comprising:

a determining module, configured to determine a location for sending a demodulation reference signal in a physical resource block, where the location for sending the demodulation reference signal includes a mapping location of a channel state information reference signal CSI-RS that has been used and/or is not used by the first device, and the demodulation reference signal is used for demodulating data of a second user equipment;

25. The first apparatus of claim 24, wherein the configuration information is non-zero power CSI-RS signaling.

26. The first apparatus of claim 24 or 25, wherein the mapping locations of the CSI-RS are a set of locations of all resource elements, REs, in the physical resource block defined in long term evolution, LTE, system release Rel-10 for placing the CSI-RS.

27. The first device according to any one of claims 24 to 26, wherein the determining module is specifically configured to:

28. The first device of any one of claims 24-27, wherein the sending module is further configured to:

29. The first device of claim 28, wherein the precoding indication is sent by the first device via Downlink Control Information (DCI) or Radio Resource Control (RRC) signaling.

30. The first device according to any one of claims 24-27, wherein the first device further comprises:

31. The first device of any one of claims 24-30, wherein the sending module is further configured to:

32. The first apparatus of claim 31, wherein the first indication information is carried by zero-power CSI-RS signaling.

33. The first device according to claim 31 or 32, wherein if the physical resource block includes a location for transmitting DM-RS to at least one first user equipment, the location indicated by the first indication information includes the location for transmitting DM-RS to the at least one first user equipment.

34. The first apparatus according to any of claims 31-33, wherein if the demodulation reference signal is used for demodulating data of two or more second ues, the location indicated by the first indication information comprises a location of a demodulation reference signal sent on the physical resource block to a second ue of the two or more second ues other than the second ue.

35. The first device of claim 33, wherein the sending module is further configured to:

36. The first apparatus of claim 35, wherein the second indication information is carried by zero-power CSI-RS signaling.

37. The first device of any one of claims 27-36, wherein the sending module is further configured to:

38. The first device of any one of claims 24-37, wherein the determination module is further configured to:

and determining a physical resource block for sending the demodulation reference signal on a full bandwidth corresponding to the first device, or determining a physical resource block for sending the demodulation reference signal on a dedicated bandwidth of the second user equipment.

39. A second user device, comprising:

a receiving module, configured to receive configuration information sent by a first device, where the configuration information is used to indicate a position of a demodulation reference signal in a physical resource block;

40. The second UE of claim 39, wherein the configuration information is non-zero power CSI-RS signaling.

41. The second UE of claim 39 or 40, wherein the mapping positions of the CSI-RS are a set of positions of all Resource Elements (REs) in the physical resource blocks defined in LTE Long Term Evolution (LTE) System Release Rel-10 for placing the CSI-RS.

42. The second ue of any one of claims 39-41, wherein the receiving module is further configured to:

receiving a precoding indication sent by the first equipment;

the second user equipment further comprises:

43. The second UE of claim 42, wherein the precoding indication is sent by the first UE via DCI or RRC signaling.

44. The second UE of any one of claims 39-41, wherein the DM-RS is a second DM-RS used for performing user data demodulation after being precoded, and the second DM-RS is a DM-RS mapped on the position of the physical resource block where the DM-RS is sent according to a preset mapping manner.

45. The second user equipment according to any of claims 39-44, wherein the receiving module is further configured to:

46. The second UE of claim 45, wherein the first indication information is carried by zero-power CSI-RS signaling.

47. A first device, comprising:

a processor, configured to determine a location in a physical resource block to transmit a demodulation reference signal, where the location to transmit the demodulation reference signal includes a mapping location of a channel state information reference signal (CSI-RS) that has been used and/or is not used by the first device, and the demodulation reference signal is used for demodulating data of a second user equipment;

48. The first apparatus of claim 47, wherein the configuration information is non-zero power CSI-RS signaling.

49. The first apparatus of claim 47 or 48, wherein the mapping locations of the CSI-RS are a set of locations of all Resource Elements (REs) in the physical resource block defined in Long Term Evolution (LTE) system release Rel-10 for placing the CSI-RS.

50. The first device of any one of claims 47-49, wherein the processor is specifically configured to:

51. The first device of any one of claims 47-50, wherein the transmitter is further configured to:

52. The first device of claim 51, wherein the precoding indication is sent by the first device via Downlink Control Information (DCI) or Radio Resource Control (RRC) signaling.

53. The first device of any one of claims 47-50, wherein the processor is further configured to:

54. The first device of any one of claims 47-53, wherein the transmitter is further configured to:

55. The first apparatus of claim 54, wherein the first indication information is carried by zero-power CSI-RS signaling.

56. The first device according to claim 54 or 55, wherein if the physical resource block includes a location for transmitting DM-RS to at least one first user equipment, the location indicated by the first indication information includes the location for transmitting DM-RS to the at least one first user equipment.

57. The first apparatus according to any of claims 54-56, wherein if the demodulation reference signal is used for demodulating data of two or more second user equipments, the location indicated by the first indication information comprises a location of a demodulation reference signal sent on the physical resource block to a second user equipment other than the second user equipment.

58. The first device of claim 56, wherein the transmitter is further configured to:

59. The first apparatus of claim 58, wherein the second indication information is carried by zero-power CSI-RS signaling.

60. The first device of any one of claims 50-59, wherein the transmitter is further configured to:

61. The first device of any one of claims 47-60, wherein the processor is further configured to:

62. A second user device, comprising:

the receiver is used for receiving configuration information sent by a first device, wherein the configuration information is used for indicating the position of a demodulation reference signal in a physical resource block;

63. The second UE of claim 62, wherein the configuration information is non-zero power CSI-RS signaling.

64. The second UE of claim 62 or 63, wherein the mapping locations of the CSI-RS are a set of locations of all Resource Elements (REs) in the physical resource blocks defined in LTE Long Term Evolution (LTE) System Release Rel-10 for placing the CSI-RS.

65. The second user equipment according to any of claims 62-64, wherein the receiver is further configured to:

receiving a precoding indication sent by the first equipment;

66. The second ue according to claim 65, wherein the precoding indication is sent by the first ue via downlink control information, DCI, or radio resource control, RRC, signaling.

67. The second user equipment according to any of claims 62-64, wherein the demodulation reference signal is a second DM-RS used for performing user data demodulation after being precoded, and the second DM-RS is a DM-RS mapped on the position of the transmitted demodulation reference signal in the physical resource block according to a preset mapping manner.

68. The second user equipment according to any of claims 62-67, wherein the receiver is further configured to:

69. The second ue of claim 68, wherein the first indication information is carried by zero-power CSI-RS signaling.