CN114448477A

CN114448477A - Communication method, communication device and system

Info

Publication number: CN114448477A
Application number: CN202210041103.7A
Authority: CN
Inventors: 黄逸; 任海豹; 李元杰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2017-06-16
Filing date: 2017-09-18
Publication date: 2022-05-06
Also published as: WO2018228599A1

Abstract

The application provides a communication method, which can provide a codebook of a higher-order precoding matrix and is beneficial to improving the number of data layers for channel transmission, thereby being beneficial to improving the data transmission capability of a communication system and improving the throughput. The method comprises the following steps: a first device receives a reference signal for channel measurement; the first device sends a Precoding Matrix Indicator (PMI) and a Rank Indicator (RI) according to the reference signal, the PMI is used for indicating a precoding matrix in a codebook corresponding to the RI, the precoding matrix in the codebook comprises a plurality of matrixes corresponding to a plurality of antenna port groups one by one, the matrix corresponding to one antenna port group or each antenna port group in at least two antenna port groups has two different antenna port group-to-group phase factors, and any two column vectors in the precoding matrix are orthogonal to each other.

Description

Communication method, communication device and system

The present application is a divisional application, the original application having application number 201710843369.2, the original application date being 09 and 18 in 2017, the entire content of the original application being incorporated by reference in the present application.

Technical Field

The present application relates to the field of wireless communication, and more particularly, to a communication method, a communication apparatus, and a system.

Background

Massive multiple-input multiple-output (Massive MIMO) is one of the key technologies of the 5th Generation mobile communication (5G) recognized in the industry. In order to avoid interference among multiple users and improve signal quality, signals can be processed in a pre-coding mode, so that space division multiplexing is realized, and the frequency spectrum utilization rate is greatly improved.

In the prior art, a network device may obtain channel state information (channel state information) fed back by a terminal device by sending, for example, a channel state information reference signal (CSI-RS), and further determine a precoding matrix adapted to a downlink channel. The number of rows of the precoding matrix may represent the number of antenna ports, and the number of columns of the precoding matrix may represent a rank (rank) corresponding to the codebook.

However, in the 5G new radio access technology (NR), the number of antenna ports is increased as the multi-antenna technology is developed. Due to the increase in the number of antenna ports, multiple antenna panels may be configured for the same network device, with multiple antenna ports configured on multiple antenna panels. Thus, a multi-panel codebook (multi-panel codebook) was introduced.

There has not been provided a method in the prior art that can provide a codebook of higher order (e.g., rank greater than 4) for the purpose of mutually orthogonalizing the column vectors in the precoding matrix.

Disclosure of Invention

The application provides a communication method, a communication device and a system, which can provide a higher-order codebook.

In a first aspect, a communication method is provided, including:

a first device receives a reference signal for channel measurement;

the first device sends a Precoding Matrix Indicator (PMI) and a Rank Indicator (RI) according to the reference signal, where the PMI is used to indicate a precoding matrix in a codebook corresponding to the RI, the precoding matrix in the codebook includes a plurality of matrices corresponding to a plurality of antenna port groups one to one, a matrix corresponding to one antenna port group or each of at least two antenna port groups has two different antenna port group-to-group phase factors, and any two column vectors in the precoding matrix are orthogonal to each other.

According to the method and the device, the precoding matrix used for the high-order codebook is provided, so that any two precoding column vectors of the precoding matrix are orthogonal to each other, and therefore transmission of a data stream with a larger number of layers can be achieved. Therefore, the method is beneficial to improving the speed of MIMO transmission, improving the data transmission capability of the communication system and improving the throughput.

Optionally, the method further comprises:

the second device transmits codebook indicating information indicating a type of a codebook used to the first device.

Optionally, the codebook type includes: a single-panel codebook or a multi-panel codebook.

Therefore, after receiving the codebook indication information, the first device may select a corresponding codebook according to the indicated codebook type.

Optionally, the method further comprises:

the first device receives codebook configuration parameters.

Optionally, the codebook configuration parameter includes any one of:

the number of antenna port groups and the number of antenna ports contained in each antenna port group;

a number of antenna port groups and a total number of antenna ports;

the total number of antenna ports and the number of antenna ports contained in each antenna port group; or,

the number of horizontal antenna ports, the number of vertical antenna ports and the number of antenna port groups contained in each antenna port group.

By indicating the codebook configuration parameters, the vector length of the precoding matrix, i.e. the number of rows of the precoding matrix, can be determined.

In addition, the first device may determine a channel matrix from the reference signal, thereby determining a rank, and thus, may determine the number of columns of the precoding matrix.

In a second aspect, a communication method is provided, including:

the second device transmits a reference signal for channel measurement;

the second device receives a PMI and an RI, the PMI and the RI are related to the reference signal, the PMI is used for indicating a precoding matrix in a codebook corresponding to the RI, the precoding matrix in the codebook comprises a plurality of matrixes in one-to-one correspondence with a plurality of antenna port groups, a matrix corresponding to one antenna port group or each antenna port group of at least two antenna port groups has two different antenna port group-to-group phase factors, and any two column vectors in the precoding matrix are orthogonal to each other. According to the method and the device, the precoding matrix used for the high-order codebook is provided, so that any two precoding column vectors of the precoding matrix are orthogonal to each other, and therefore transmission of a data stream with a larger number of layers can be achieved. Therefore, the method is beneficial to improving the speed of MIMO transmission, improving the data transmission capability of the communication system and improving the throughput.

Optionally, the method further comprises:

the first device receives codebook configuration parameters. Optionally, the codebook configuration parameter includes any one of:

a number of antenna port groups and a total number of antenna ports;

The application also provides a communication device corresponding to the communication method of the first aspect. The communication device may be any transmitting end device or receiving end device that performs data transmission in a wireless manner. Such as a communication chip, a terminal device, or a network device (e.g., a base station, etc.). During communication, the device on the transmitting side and the device on the receiving side are opposite. The communication apparatus may serve as the first device in some communication procedures, and may serve as the second device in some communication procedures. For example, for downlink data transmission, a device at a transmitting end is a base station, and a corresponding device at a receiving end is a terminal device; for uplink data transmission, the equipment at the transmitting end is terminal equipment, and the corresponding equipment at the receiving end is a base station; for data transmission of D2D (device to device), a device at a transmitting end is a terminal device, and a corresponding device at a receiving end may also be a terminal device. The communication method is not limited in the present application.

The reference signal may be a reference signal for uplink channel measurement, a reference signal for downlink channel measurement, or a reference signal for another communication method. For example, if the reference signal is a reference signal for uplink channel measurement, the first device may be a terminal device or a communication chip usable for the terminal device, and the second device is a network device or a communication chip usable for the network device. For another example, if the reference signal is a reference signal for downlink channel measurement, the first device may be a network device or a communication chip available to the network device, and the second device may be a terminal device or a communication chip available to the terminal device.

In a third aspect, a communication device is provided, which includes a sending unit and a receiving unit to perform the method in any one of the possible implementations of the first or second aspect. The transmitting unit is used for executing functions related to transmission, and the receiving unit is used for executing functions related to reception.

In one design, the communication device is a communication chip, the sending unit may be an input circuit or an interface of the communication chip, and the sending unit may be an output circuit or an interface of the communication chip.

In another embodiment, the communication device is a terminal device, and the sending unit may be a transmitter or a transmitter.

In another design, the communication device is a network device and the sending unit may be a receiver or a receiver.

Optionally, the communication device further includes various modules operable to execute the communication method in any possible implementation manner of the first aspect or the second aspect.

In a fourth aspect, a communication device is provided, which includes a processor and a memory, wherein the memory is used for storing a computer program, and the processor is used for calling the computer program from the memory and running the computer program, so that the communication device executes the method in any one of the possible implementation manners of the first or second aspect.

Optionally, the number of the processors is one or more, and the number of the memories is one or more.

Alternatively, the memory may be integral with the processor or separate from the processor.

Optionally, the communication device further comprises a transmitter (transmitter) and a receiver (receiver).

In one possible design, a terminal device is provided that includes a transceiver, a processor, and a memory. The processor is configured to control the transceiver to transceive signals, the memory is configured to store a computer program, and the processor is configured to retrieve and execute the computer program from the memory, so that the terminal device performs the method of the first aspect or any one of the possible implementation manners of the first aspect.

In another possible design, a network device is provided that includes a transceiver, a processor, and a memory. The processor is configured to control the transceiver to transmit and receive signals, the memory is configured to store a computer program, and the processor is configured to call and execute the computer program from the memory, so that the network device executes the method of the second aspect or any possible implementation manner of the second aspect.

In a fifth aspect, a system is provided, where the system includes the terminal device and the network device.

In a sixth aspect, there is provided a computer program product comprising: a computer program (which may also be referred to as code, or instructions), which when executed, causes a computer to perform the method of any of the possible implementations of the first or second aspect described above.

In a seventh aspect, a computer-readable medium is provided, which stores a computer program (which may also be referred to as code or instructions) that, when executed on a computer, causes the computer to perform the method of any one of the above-mentioned first or second aspects.

In any one of the above aspects, the first and second electrodes,

optionally, the column number of the precoding matrix corresponds to a rank, the row number of the precoding matrix corresponds to the total number of the antenna ports, where the rank is M, the number of the antenna port groups is N, a matrix corresponding to N/2 antenna port groups in the precoding matrix includes a first column vector set and a second column vector set, the antenna port inter-group phase factor of the first column vector set and the antenna port inter-group phase factor of the second column vector set are opposite numbers, where M is an integer greater than 1, and N is an even number greater than or equal to 2.

Optionally, each antenna port group (e.g., one antenna port group for each antenna panel) includes 2N₁ N₂Individual CSI-RS antenna ports, N₁Representing the number of transverse CSI-RS antenna ports, N₂The number of the longitudinal CSI-RS antenna ports is represented, and the total number of the N antenna port groups containing the antenna ports is P_CSI-RS＝2NN₁N₂Wherein N is an even number greater than or equal to 2, N₁Is an integer greater than or equal to 1, N₂Is an integer greater than or equal to 1.

The precoding matrix provides one possible form for a codebook of order 8.

In one possible design, M is 8, N is 2, and the precoding matrix in the codebook corresponding to the rank is, or, satisfies:

or, with said W₁A matrix having row and/or column transformation relationships;

or, W₁And a constant coefficient, e.g. constant coefficient

Or, with said W₁Matrix with row and/or column transformation relationshipsThe product of a constant coefficient, e.g. constant coefficient may be

Wherein, b₁、b₂For the discrete fourier transform, DFT, vector, c for the polarized antenna phase factor,

is a phase factor between two antenna port groups corresponding to one antenna port group, and

in one possible design, M < 8, N is 2, and the precoding matrix in the codebook corresponding to the rank includes M column vectors, where the M column vectors are a subset of the following precoding matrices or the column vectors in the precoding matrix satisfying the following equation:

or is W₁And a constant coefficient, e.g. constant coefficient

Or, with said W₁A matrix having a row and/or column transformation relationship, multiplied by a constant coefficient, e.g. constant coefficient

the precoding matrix provides a possible form for a codebook with an order of 5-7.

That is, the precoding matrix in the corresponding codebook when the rank takes the maximum value may have a nested property.

In one possible design, M is 8, N is 4, and the precoding matrix in the codebook corresponding to the rank is, or, satisfies:

or, with said W₂A matrix having row and/or column transformation relationships;

or, W₂And a constant coefficient, e.g. constant coefficient

Or, with said W₂The product of a matrix having a row and/or column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein, b₁、b₂Is the DFT vector, c is the polarized antenna phase factor,

and

and

and with

Three groups of antenna port inter-group phase factors corresponding to the three antenna port groups one by one, wherein the values of the two groups of antenna port inter-group phase factors satisfy

The value of the inter-group phase factor for the other group of antenna ports is satisfied,

i is 1,2 or 3.

The precoding matrix provides yet another possible form for a codebook of order 8.

or with the above-mentioned W₂' a matrix having row and/or column transformation relationships;

or, W₂' and a constant coefficient, e.g. the constant coefficient may be

Or, with the above W₂' multiplication of a matrix having a row and/or column transformation relationship with a constant coefficient, e.g. the constant coefficient may be

Wherein, b₁、b₂Is a discrete Fourier transformThe DFT vector is the interior transform, c is the polarization antenna phase factor,

α₁₁，α₁₂，α₁₃，α₁₄two of the values are +1, and the other two values are-1;

α₂₁，α₂₂，α₂₃，α₂₄two of the values are +1, and the other two values are-1;

β₁₁，β₁₂，β₁₃，β₁₄two of the values are +1, and the other two values are-1;

β₂₁，β₂₂，β₂₃，β₂₄two of which are +1 and the other two are-1.

Wherein the two parameters of 1 and the two parameters of-1 can be defined by a protocol and pre-stored in the corresponding device. The terminal device can also be configured through the network device.

In one possible design, M < 8, N is 4, and the precoding matrix in the rank-mapped codebook includes M column vectors, where the M column vectors are a subset of the following precoding matrices or the column vectors in the precoding matrix satisfying the following equation:

or, W₂And a constant coefficient, e.g. constant coefficient

Wherein, b₁、b₂Is the DFT vector, c is the polarized antenna phase factor,

and

and

and

The value of the phase factor between the other antenna port group satisfies

i is 1,2 or 3.

The precoding matrix provides another possible form for a codebook with the order of 5-7.

In one possible design, when M is 4, N is 2, and the codebook mode is codebook mode 1, the precoding matrix in the codebook corresponding to the rank is, or, satisfies:

or with W₈Matrix with row and/or column transformation relationships；

Or, W₈And a constant coefficient, e.g. constant coefficient

Or alternatively with W₈The product of a matrix having a row and/or column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein, the equation after the first equal sign is used for description,

the phase factor of the polarized antenna can be taken as the value in { +1, -1, + j, -j }, and the value of n is the value in {0,1,2,3 };

and

for the inter-antenna port group phase factor,

can take the value p in { +1, -1, + j, -j { (R) }₁Is the value in {0,1,2,3 }.

The precoding matrix provides yet another possible form for a codebook of order 4.

In one possible design, when the codebook mode is codebook mode 1, the precoding matrix in the codebook corresponding to the rank includes 3 column vectors, where the 3 column vectors are a subset of the following precoding matrix or the precoding matrix satisfying the following equation:

or with W₈A matrix having row and/or column transformation relationships;

or, W₈And a constant coefficient, e.g. constant coefficient

Wherein, the equation after the first equal sign is used for description,

and

for the inter-antenna port group phase factor,

can take the value p in { +1, -1, + j, -j { (R) }₁Is the value in {0,1,2,3 }.

The precoding matrix provides yet another possible form for a codebook of order 3.

In one possible design, when M is 4, N is 4, and the codebook mode is codebook mode 1, the precoding matrix in the codebook corresponding to the rank is, or, satisfies:

or alternatively with W₁₀A matrix having row and/or column transformation relationships;

or, W₁₀And a constant coefficient, e.g. constant coefficient

Or alternatively with W₁₀The product of a matrix having a row and/or column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein, the equation after the first equal sign is used for description,

for the inter-antenna port group phase factor,

can take the value p in { +1, -1, + j, -j { (R) }₁The value of (a) is the value in {0,1,2,3 };

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

can take the value p in { +1, -1, + j, -j { (R) }₂The value of (a) is the value in {0,1,2,3 };

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

can take the value p in { +1, -1, + j, -j { (R) }₃Is the value in {0,1,2,3 }.

or, W₁₀And a constant coefficient, e.g. constant coefficient

Wherein, the equation after the first equal sign is used for description,

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

values, p, can be taken from { +1, -1, + j, -j }₂The value of (a) is the value in {0,1,2,3 };

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

can take the value p in { +1, -1, + j, -j { (R) }₃Is the value in {0,1,2,3 }.

Optionally, when M is 4, N is 2, and the codebook mode is codebook mode 2, the precoding matrix in the codebook corresponding to the rank is, or, satisfies:

or alternatively with W₉A matrix having a row/column transformation relationship;

or, W₉And a constant coefficient, e.g. constant coefficient

Or alternatively with W₉Matrix with row/column conversion relation and constant systemMultiplication of numbers, e.g. constant coefficients may be

Wherein,

for the polarized antenna phase factor, the value can be set in { +1, -1, + j, -j } and the value of n is set in {0,1,2,3 }.

Has a value of

p₁The value of (a) is the value in {0,1,2,3 };

has a value of

p₂The value of (a) is the value in {0,1,2,3 }; b_n1Has a value of

n₁Is the value in {0,1 }; b_n2Has a value of

n₂Is the value in {0,1 }.

Optionally, when the codebook mode is codebook mode 2, the precoding matrix in the codebook corresponding to the rank includes 3 column vectors, where the 3 column vectors are a subset of the following precoding matrix or the column vectors in the precoding matrix that satisfies the following equation:

or with W₉A matrix having a row/column transformation relationship;

or, W₉And a constant coefficient, e.g. constant coefficient

Or alternatively with W₉The product of a matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein,

Has a value of

p₁The value of (a) is the value in {0,1,2,3 };

has a value of

p₂The value of (a) is the value in {0,1,2,3 }; b_n1Has a value of

n₁Is the value in {0,1 }; b_n2Has a value of

n₂Is the value in {0,1 }.

Optionally, when the codebook mode is codebook mode 2, the design also satisfies that a matrix corresponding to one antenna port group or each antenna port group of the at least two antenna port groups has two different inter-antenna port group phase factors, and any two column vectors in the precoding matrix are orthogonal to each other. The above description does not give a specific form of the inter-antenna port group phase factor due to its complex deformation, but this does not affect the implementation of the scheme.

Alternatively, the form of the precoding matrix in the above possible designs may be individually protected if necessary, without being limited to the description of the aforementioned first aspect or second aspect.

Optionally, values of the parameters may be predefined by a protocol, or may be determined by configuration between the network device and the terminal device.

In the above possible designs, the corresponding PMI feedback mechanism may also include the following possible designs:

one possible design is to quantize only the antenna port inter-group phase factor, or to quantize only the polarized antenna phase factor. Correspondingly, the PMIs include a first PMI, a second PMI or a third PMI, the first PMI is used for indicating a DFT vector, the second PMI is used for indicating the antenna port inter-group phase factor, and the third PMI is used for indicating a polarized antenna phase factor. Alternatively, the PMIs include a first PMI and a tenth PMI. The first PMI is used for indicating a DFT vector, and the tenth PMI is used for indicating the antenna port inter-group phase factor or indicating a polarized antenna phase factor. Alternatively, the PMIs include an eleventh PMI, where the eleventh PMI corresponds to a plurality of indication fields (e.g., includes a plurality of indication fields), and one of the indication fields is used to indicate a DFT vector, and another of the indication fields is used to indicate an antenna port inter-group phase factor, or to indicate a polarized antenna phase factor. This feedback mechanism can achieve the effect of saving signaling overhead by solidifying one parameter.

In another possible design, the inter-antenna port phase factor and the polarized antenna phase factor are quantized simultaneously.

Correspondingly, the PMIs include a first PMI, a second PMI and a third PMI, the first PMI is used for indicating a DFT vector, the second PMI is used for indicating the antenna port inter-group phase factor, and the third PMI is used for indicating a polarized antenna phase factor.

Or, the PMIs include a first PMI and a fourth PMI, the first PMI is used for indicating a DFT vector, and the fourth PMI is used for indicating the antenna port inter-group phase factor and the polarized antenna phase factor. Alternatively, the PMIs include a twelfth PMI and a third PMI. The twelfth PMI corresponds to (e.g., includes) a plurality of indication fields, one of the indication fields is used for indicating a DFT vector, another of the indication fields is used for indicating an antenna port inter-group phase factor, and the third PMI is used for indicating a polarization antenna phase factor. The feedback mechanism can carry a plurality of factors for indicating by one PMI, and can save signaling overhead.

Optionally, M is 8, N is 2, and a precoding matrix in a codebook corresponding to the rank is, or, satisfies:

or with said W₃A matrix having row and/or column transformation relationships;

or, W₃And a constant coefficient, e.g. constant coefficient

Or, with said W₃The product of a matrix having a row and/or column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein, b₁、b₂Is a DFT vector, z₁＝1，z₂Is a polarized antenna phase factor, z₃、-z₃Is the inter-antenna port group phase factor, z₄For the polarized antenna phase factor and the antenna portThe product of the intergroup phase factors.

Optionally, M < 8, N is 2, and the precoding matrix in the codebook corresponding to the rank includes M column vectors, where the M column vectors are a subset of the following precoding matrix or the column vectors in the precoding matrix satisfying the following equation:

or, W₃And a constant coefficient, e.g. constant coefficient

Wherein, b₁、b₂Is a DFT vector, z₁＝1，z₂Is a polarized antenna phase factor, z₃、-z₃Is the inter-antenna port group phase factor, z₄Is the product of the polarized antenna phase factor and the antenna port group phase factor.

The precoding matrix provides one possible form for a codebook of order 8.

Wherein z is_kThe value of (b) can be solidified or quantified, and the value of k is 2,3 and 4.

In one possible design, z is_kIs a value of { +1, -1, + j, -j }, and k is a value of 2,3, 4.

Correspondingly, the PMI comprises a first PMI and a fifth PMI, and the first PMI is usedIn indicating DFT vector, the fifth PMI is used to indicate z₂、z₃、z₄At least one of (a).

In one possible design, z is_m＝x_m×y_m，x_mAnd y_mIs z_mM takes on one or more of the

values

2,3, 4.

Optionally, x_mIs a component related to the bandwidth, y_mAre subband dependent components.

Correspondingly, the PMIs comprise a first PMI, a sixth PMI and a seventh PMI, wherein the first PMI is used for indicating a DFT vector, and the sixth PMI is used for indicating x_mThe seventh PMI is used to indicate y_m。

Wherein if m takes on a plurality of values, i.e. a plurality of z are quantized_mA plurality of indicators y may be included in the seventh PMI_mThe information of (1).

The PMIs include an eighth PMI and a ninth PMI, the eighth PMI indicating a DFT vector sum x_mNinth PMI for indicating y_m。

In this design, the DFT vector sum x will be used to indicate wideband feedback_mThe information of (2) is carried in the same PMI, and y used for indicating subband feedback_mThe information is carried in a PMI, so that the number of PMIs can be reduced, and the signaling overhead is saved. According to the method and the device, the precoding matrix used for the high-order codebook is provided, so that any two precoding column vectors of the precoding matrix are orthogonal to each other, and therefore transmission of a data stream with a larger number of layers can be achieved. Therefore, the method is beneficial to improving the MIMO transmission rate, improving the data transmission capability of the communication system and improving the throughput.

Drawings

Fig. 1 is a schematic diagram of a communication system suitable for use in the communication method of the embodiment of the present application;

fig. 2 is a schematic diagram of a downlink physical channel processing procedure adopted in an existing LTE system;

fig. 3 is a schematic diagram illustrating a plurality of antenna ports configured in a plurality of antenna panels;

fig. 4 is a schematic flow chart of a communication method provided by an embodiment of the present application;

fig. 5 is a schematic flow chart of a communication method provided by another embodiment of the present application;

fig. 6 is a schematic diagram of a communication device provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a terminal device provided in an embodiment of the present application;

fig. 8 is another schematic diagram of a communication device provided in an embodiment of the present application;

fig. 9 is a schematic structural diagram of a network device according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

It should be understood that the technical solution of the present application can be applied to various communication systems, for example: a Global System for Mobile communications (GSM) System, a Code Division Multiple Access (CDMA) System, a Wideband Code Division Multiple Access (WCDMA) System, a General Packet Radio Service (GPRS), a Long Term Evolution (LTE) System, an advanced long term evolution (LTE-a) System, a Universal Mobile Telecommunications System (UMTS), a next generation communication System (e.g., a fifth-generation communication (5G) System), a fusion System of Multiple Access systems, an evolution System, or the like. Among them, the 5G system may also be referred to as a new generation radio access technology (NR) system.

For the understanding of the embodiments of the present application, a communication system suitable for the embodiments of the present application will be described in detail with reference to fig. 1. Fig. 1 shows a schematic diagram of a communication system suitable for the method and apparatus for data transmission of the embodiments of the present application. As shown in fig. 1, the communication system 100 includes a network device 102, and the network device 102 may include a plurality of antennas, e.g.,

antennas

104, 106, 108, 110, 112, and 114. Additionally, network device 102 can additionally include a transmitter chain and a receiver chain, each of which can comprise a plurality of components associated with signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, etc.), as will be appreciated by one skilled in the art.

It should be understood that the network device may be any device with wireless transceiving function or a chip disposed on the device, and the device includes but is not limited to: a base station (e.g., a base station NodeB, an evolved node b, a network device in a fifth generation (5G) communication system (e.g., a Transmission Point (TP), a Transmission Reception Point (TRP), a base station, a small base station device, etc.), a network device in a future communication system, an access node in a WiFi system, a wireless relay node, a wireless backhaul node, etc.

Network device 102 may communicate with a plurality of terminal devices, such as terminal device 116 and terminal device 122. Network device 102 may communicate with any number of terminal devices similar to

terminal devices

116 or 122.

It should be understood that a terminal device may also be referred to as a User Equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The terminal device in the embodiment of the present application may be a mobile phone (mobile phone), a tablet computer (Pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical treatment (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and the like. The embodiments of the present application do not limit the application scenarios. In the present application, the terminal device and the chip that can be installed in the terminal device are collectively referred to as a terminal device.

As shown in fig. 1, terminal device 116 is in communication with

antennas

112 and 114, where

antennas

112 and 114 transmit information to terminal device 116 over forward link 118 and receive information from terminal device 116 over reverse link 120. In addition, terminal device 122 is in communication with

antennas

104 and 106, where

antennas

104 and 106 transmit information to terminal device 122 over forward link 124 and receive information from terminal device 122 over reverse link 126.

The embodiments of the present application may be applicable to downlink data transmission, may also be applicable to uplink data transmission, and may also be applicable to device-to-device (D2D) data transmission. For example, for downlink data transmission, a device at a transmitting end is a base station, and a corresponding device at a receiving end is a UE; for uplink data transmission, the equipment at the transmitting end is UE, and the corresponding equipment at the receiving end is a base station; for data transmission of D2D, the transmitting device is a UE and the corresponding receiving device is also a UE. The embodiments of the present application do not limit this.

In a Frequency Division Duplex (FDD) system, forward link 118 may utilize a different frequency band than that used by reverse link 120, and forward link 124 may utilize a different frequency band than that used by reverse link 126, for example.

As another example, in Time Division Duplex (TDD) systems and full duplex (full duplex) systems, forward link 118 and reverse link 120 may utilize a common frequency band and forward link 124 and reverse link 126 may utilize a common frequency band.

Each antenna (or group of antennas consisting of multiple antennas) and/or area designed for communication is referred to as a sector of network device 102. For example, antenna groups may be designed to communicate to terminal devices in a sector of the areas covered by network device 102. During communication by network device 102 with

terminal devices

116 and 122 over

forward links

118 and 124, respectively, the transmitting antennas of network device 102 may utilize beamforming to improve signal-to-noise ratio of

forward links

118 and 124. Moreover, mobile devices in neighboring cells can experience less interference when network device 102 utilizes beamforming to transmit to

terminal devices

116 and 122 scattered randomly through an associated coverage area, as compared to a manner in which a network device transmits through a single antenna to all its terminal devices.

Network device 102, terminal device 116, or terminal device 122 may be a wireless communication transmitting apparatus and/or a wireless communication receiving apparatus. When sending data, the wireless communication sending device may encode the data for transmission. In particular, a wireless communication transmitting device may acquire (e.g., generate, receive from other communication devices, or save in memory, etc.) a number of data bits to be transmitted over a channel to a wireless communication receiving device. Such data bits may be contained in a transport block (or transport blocks) of data, which may be segmented to produce multiple code blocks.

Furthermore, the communication system 100 may be a Public Land Mobile Network (PLMN) network or a device to device (D2D) network or a machine to machine (M2M) network or other networks, which is illustrated in fig. 1 for ease of understanding only, and other network devices may be included in the network, which are not shown in fig. 1.

For the convenience of understanding the embodiment of the present application, a process of processing a downlink physical channel in an LTE system is briefly described below with reference to fig. 2. Fig. 2 is a schematic diagram of a downlink physical channel processing procedure adopted in an existing LTE system. The processing object of the downlink physical channel processing procedure is a codeword, and the codeword is usually a coded (at least including channel coding) bit stream. The code word is scrambled (scrambled) to generate a scrambled bit stream. The scrambled bit stream is subjected to modulation mapping (modulation mapping) to obtain a modulation symbol stream. For the convenience of distinction and illustration, the symbol stream after layer mapping may be referred to as a layer mapping space layer (or layer mapping space stream, layer mapping symbol stream) in the embodiments of the present application. The layer mapped spatial layers are precoded (precoding) resulting in a plurality of precoded data streams (or, alternatively, precoded symbol streams). The precoded symbol streams are mapped onto multiple REs via Resource Element (RE) mapping. These REs are then Orthogonal Frequency Division Multiplexing (OFDM) modulated, generating a stream of OFDM symbols. The OFDM symbol stream is then transmitted through an antenna port (antenna port).

The precoding technique may be to perform pre-processing on a signal to be transmitted at a transmitting end under the condition of a known channel state, that is, to process the signal to be transmitted by using a precoding matrix matched with a channel resource, so that the pre-coded signal to be transmitted is adapted to a channel, and complexity of eliminating inter-channel influence at the receiving end is reduced. Therefore, through the pre-coding process of the transmitted signal, the quality of the received signal (e.g., signal to interference plus noise ratio (SINR)) is improved. Therefore, by using the precoding technology, the transmission of the transmitting end device and the multiple receiving end devices on the same time-frequency resource can be realized, that is, the multi-user multiple input multiple output (MU-MIMO) is realized. It should be noted that the description related to the precoding technology is only for example, and is not used to limit the protection scope of the embodiment of the present application, and in the specific implementation process, precoding may also be performed in other manners (for example, precoding is performed by using a preset precoding matrix or a weighting processing manner when a channel matrix cannot be known), and details are not repeated herein.

In order to obtain a precoding matrix that can be adapted to a channel, a transmitting end performs channel estimation in advance, usually by sending a reference signal, and obtains feedback from a receiving end, thereby determining a more accurate precoding matrix to perform precoding processing on data to be transmitted. Specifically, the sending end may be a network device, the receiving end may be a terminal device, the reference signal may be a reference signal used for downlink channel measurement, for example, a channel state information reference signal (CSI-RS), and the terminal device may perform CSI measurement according to the received CSI-RS and feed back CSI of a downlink channel to the network device; the sending end may also be a terminal device, the receiving end may be a network device, and the reference signal may be a reference signal used for uplink channel measurement, for example, a Sounding Reference Signal (SRS). The network device may perform CSI measurement according to the received RSR, and indicate CSI of the uplink channel to the terminal device. The CSI may include, for example, a Precoding Matrix Indicator (PMI), a Rank Indicator (RI), a Channel Quality Indicator (CQI), and the like.

As multi-antenna technology has evolved, the number of antenna ports has also increased. Due to the increase in the number of antenna ports, multiple antenna panels may be configured for the same network device, and multiple antenna ports may be configured on multiple antenna panels. For example, at least one antenna port is configured on each antenna panel, and the at least one antenna port configured on each antenna panel may be referred to as an antenna port group.

Fig. 3 is a schematic diagram illustrating a plurality of antenna ports configured in a plurality of antenna panels. Specifically, a schematic diagram of configuring a plurality of antenna ports in 2 antenna panels is shown in fig. 3. Wherein each antenna panel is configured with 4 antenna ports, each x in the figure represents two antenna ports of different polarization directions. Each antenna panel in the figure is configured with 4 antenna ports. In antenna panel #1, antenna port 0 and antenna port 1 are antenna ports of the same polarization direction, and correspond to the same beam vector (or precoding vector), for example, denoted by b₁Antenna port 4 and antenna port 5 are antenna ports of the same polarization direction and correspond to another same beam vector, for example, denoted by b₂. Similarly, on antenna panel #2, antenna port 2 and antenna port 3 correspond to beam vector b₁Antenna port 6 and antenna port 7 correspond to beam vector b₂. Wherein, b₁And b₂The vector may be two orthogonal Discrete Fourier Transform (DFT) vectors, or may also be a mathematical vector characterizing the electromagnetic wave in space, which is not particularly limited in the embodiment of the present application.

It should be noted that, for convenience of understanding, the case where multiple antenna ports are configured in multiple antenna panels is described above with reference to fig. 3, but the corresponding relationship between the antennas and the antenna ports is not limited in the embodiments of the present application, and one or more physical antennas may be configured as one antenna port. In other words, an antenna port may be understood as a transmitting antenna recognized by a receiving end device, or a transmitting antenna that is spatially distinguishable. One antenna port is configured for each virtual antenna, each virtual antenna may be a weighted combination of multiple physical antennas, each antenna port corresponding to one reference signal.

In the prior art, the precoding matrix in the multi-panel codebook may be formed by splicing precoding matrices in a plurality of single-panel codebooks (single-panel codebooks), and different antenna panels are distinguished by an antenna panel phase factor. For example, one antenna panel corresponds to one antenna panel phase factor. Any two column vectors in the precoding matrix satisfy a mutually orthogonal relationship, and therefore, the number of columns of the precoding matrix is limited by the number of antenna ports. For example, when the number of antenna ports configured for each antenna panel is 4, only 4 mutually orthogonal column vectors can be formed at most, that is, the rank is 4 at most.

Referring to fig. 3 again, taking any one of the antenna panels in fig. 3 as an example, the structure of the precoding vector with rank 1 corresponding to the antenna port configured on one antenna panel may be:

wherein c is a polarization antenna phase factor and can be arbitrarily selected from { +1, -1, + j, -j }. It should be understood that the precoding vector illustrated herein is only one possible structural illustration, and should not constitute any limitation to the embodiments of the present application.

It should be noted that the polarization antenna phase factor can be understood as a phase factor for distinguishing antenna ports with different polarization directions.

Thus, 4 orthogonal precoded column vectors that can be formed by 4 antenna ports on one antenna panel can be obtained as:

i.e., the rank is 4.

If the antenna panel phase factors of two antenna panels are considered

4 orthogonal precoded column vectors can be formed:

wherein,

any value can be selected from { +1, -1, + j, -j }.

It should be noted that the inter-antenna port group phase factor may also be referred to as an inter-antenna panel phase factor, and may be understood as a phase factor for distinguishing antenna ports in different antenna port groups (or antenna panels). The specific value can be determined according to the distance between the antenna panel and the antenna panel or the calibration error.

It should be further noted that the mutual orthogonality of the two precoding column vectors means: the product of the conjugate transpose of one pre-coded column vector and the other pre-coded column vector is zero.

However, there is no method provided in the prior art, which can provide a codebook with higher order (for example, rank greater than 4) to achieve the purpose that the column vectors in the precoding matrix are orthogonal to each other, so that a precoding matrix with higher order cannot be provided to precode data. For example, the number of antenna ports of each antenna panel configuration shown in fig. 3 is 4, and only precoding matrices of ranks 1 to 4 can be provided, but precoding matrices of ranks 5 to 8 cannot be provided.

Typically, the number of layers of data is less than or equal to the maximum number of antenna ports supported by the communication system. The maximum number of antenna ports supported by the current communication system is 8, but with the development of 5G, the maximum number of antenna ports may tend to be larger, for example, 16, 32 or even 64. If a precoding matrix with a higher order cannot be provided to precode data, the number of concurrent data streams in MIMO transmission is greatly limited, so that the data transmission capability of the communication system is limited, and the throughput is affected.

Therefore, the present application provides a communication method, which can provide a codebook with a higher order number, thereby facilitating to improve the data transmission capability of the communication system and improve the throughput.

It should be understood that the communication method provided by the present application can be applied to uplink transmission and downlink transmission. In downlink transmission, the first device in this embodiment may be a terminal device, the second device may be an access network device, and the reference signal may be a reference signal used for downlink channel measurement, for example, CSI-RS; in downlink transmission, the first device in this embodiment may be an access network device, the second device may be a terminal device, and the reference signal may be a reference signal used for uplink channel measurement, for example, an SRS. The following describes a communication method according to an embodiment of the present application in detail, taking uplink channel measurement and downlink channel measurement as examples, respectively, with reference to the accompanying drawings. It should be understood, however, that the above-listed reference signals for uplink channel measurement and downlink channel measurement are only exemplary, and should not constitute any limitation to the embodiments of the present application, and the present application does not exclude the possibility of defining other reference signals for uplink or downlink channel measurement in the existing protocol (e.g., LTE protocol) or future protocol.

Fig. 4 is a schematic flow chart of a communication method provided by the embodiment of the present application, which is shown from the perspective of device interaction. In particular, fig. 4 shows a scenario of downlink channel measurement. As shown, the method shown in fig. 4 may include steps 410 through 460.

In step 410, the network device transmits a reference signal.

Correspondingly, in step 410, the terminal device receives a reference signal from the network device.

In an embodiment of the present application, the network device may be configured with a plurality of antenna panels, each antenna panel being configured with an antenna port group, each antenna port group including at least one antenna port. For example, the antenna panel may be an antenna panel as shown in fig. 3, and of course, the antenna panel may also be configured with more antenna ports, or the network device may also be configured with more antenna panels, which is not particularly limited in this embodiment of the present application.

Alternatively, the network device may be configured with only one antenna panel, and at least one antenna port may be configured in the antenna panel.

It is understood that the codebook corresponding to when the network device configures a plurality of antenna panels and configures only one antenna panel may be different. The difference between the multi-panel codebook and the single-panel codebook has been described above with reference to the schematic diagram of the antenna panel in fig. 3, and is not described here again to avoid redundancy.

In addition, the network device may also notify the terminal device of information such as a codebook type, codebook configuration parameters, and the like, so that the network device and the terminal device use the same codebook, thereby determining a precoding matrix based on the same codebook.

Optionally, the method 400 further comprises: in step 420, the network device sends codebook indicating information to the terminal device, where the codebook indicating information is used to indicate the type of the codebook.

In one possible design, the codebook indicating information may be configured in higher layer signaling. For example, the codebook instruction information is arranged in a Radio Resource Control (RRC) message. Specifically, the codebook indication information may be carried by an indication field in the RRC message, for example, the indication field may be 1-bit indicator bits, and the multi-panel codebook or the single-panel codebook may be indicated by "1" or "0". When receiving the codebook indication information, the terminal device may determine that the PMI to be fed back for channel measurement is a PMI of the multi-panel codebook when receiving the reference signal transmitted by the network device.

In step 430, the terminal device sends the PMI and RI to the network device according to the reference signal.

First, the terminal device may estimate a channel matrix according to the received reference signal, and determine a rank of the channel matrix, that is, a column number of a precoding matrix, so that a codebook corresponding to the rank may be determined.

In a possible implementation manner, after the terminal device measures the channel matrix H according to the reference signal, a precoding matrix closest to the ideal precoding matrix may be determined from the codebook by performing Singular Value Decomposition (SVD) on the channel matrix H.

Specifically, after performing SVD on the channel matrix, the following results are obtained:

H＝U·S·V^H

wherein, U, V^HIs a unitary matrix, S is a diagonal matrix, and its non-zero elements (i.e. elements on the diagonal) are singular values of the channel matrix H, which can be generally arranged in descending order. Right unitary matrix V^HThe conjugate transpose of V is the ideal precoding matrix. In other words, the ideal precoding matrix is the precoding matrix calculated from the channel matrix H.

The terminal device may compare each candidate precoding matrix in the codebook determined above with the ideal precoding matrix to determine a precoding matrix closest to the ideal precoding matrix. The closest precoding matrix is the precoding matrix fed back to the network device by the terminal device through the PMI (for convenience of distinction and explanation, it is noted as the first precoding matrix, and it is understood that the first precoding matrix is the precoding matrix closest to the ideal precoding matrix).

The terminal device may determine the precoding matrix closest to the ideal precoding matrix in various ways, for example, the closest precoding matrix may be determined by determining the euclidean distance between each candidate precoding matrix and the ideal precoding matrix.

It should be understood that the method for determining an ideal precoding matrix through SVD in the above example is only one possible implementation manner for determining an ideal precoding matrix, and should not constitute any limitation to the embodiments of the present application. The terminal device may also determine the rank and precoding matrix by using a receiver algorithm such as Minimum Mean Square Error (MMSE), zero-forcing (ZF), Maximum Ratio Combining (MRC), throughput maximization, SINR maximization, or other criteria, so as to determine the RI and PMI to be fed back to the network device.

It should also be understood that the specific method for the terminal device to determine the channel matrix according to the reference signal and determine the rank and the precoding matrix according to the channel matrix may be the same as the prior art, and a detailed description of the specific procedure thereof is omitted here for the sake of brevity.

After determining the first precoding matrix according to the RI, the terminal device may send a PMI corresponding to the first precoding matrix to the network device, so that the network device can determine a precoding matrix for precoding downlink data to be sent (for convenience of distinguishing and explaining, it is referred to as a second precoding matrix).

In the embodiment of the present application, the first precoding matrix determined by the terminal device from the codebook may include a plurality of matrices corresponding to the plurality of antenna port groups one to one. A matrix corresponding to one antenna port group has two different antenna port inter-group phase factors, or a matrix corresponding to each of at least two antenna port groups has two different antenna port inter-group phase factors; any two column vectors in the precoding matrix are orthogonal to each other.

Optionally, the number of columns of the first precoding matrix corresponds to a rank and the number of rows corresponds to the total number of antenna ports, or the number of columns of the first precoding matrix represents a value of the rank and the number of rows represents the total number of antenna ports. For convenience of description, the rank is denoted as M (M is greater than 1, M is an integer), the number of antenna port groups is denoted as N (N is greater than or equal to 2, N is an even number), and then the first precoding matrix satisfies the following condition: the matrix corresponding to the N/2 antenna port groups in the first precoding matrix includes a first column vector set and a second column vector set, and the inter-antenna port phase factors of the first column vector set and the inter-antenna port phase factors of the second column vector set are opposite numbers.

Optionally, each antenna port group (e.g., one antenna port group for each antenna panel) includes 2N₁ N₂Individual CSI-RS antenna ports, N₁Representing the number of transverse CSI-RS antenna ports, N₂The number of the longitudinal CSI-RS antenna ports is represented, and the total number of the N antenna port groups containing the antenna ports is P_CSI-RS＝2NN₁N₂。

Wherein the column vectors in the first set of column vectors and the second set of column vectors have the same number of rows, i.e. the total number of antenna ports. In addition, in the embodiment of the present application, the arrangement order of each column vector in the first column vector set and each column vector in the second column vector set in the first precoding matrix is not limited, and the first precoding matrix can still satisfy that any two column vectors are orthogonal to each other after being subjected to row/column transformation.

The precoding matrix proposed in the present application will be described in detail later with reference to a specific precoding matrix.

Optionally, the terminal device may further determine, according to the codebook configuration parameter received in step 430, a codebook corresponding to the rank.

Optionally, the method 400 further comprises: step 440, the network device sends codebook configuration parameters to the terminal device.

In step 440, the network device may further notify the terminal device of the codebook configuration parameter, so that the terminal device determines the vector length of the precoding matrix, that is, the number of rows of the precoding matrix according to the codebook configuration parameter.

It should be understood that the above step numbers do not limit the sequence of the steps, and the sequence of the steps can be determined according to the implementation of the scheme. For example, step 420 may precede step 430 or follow step 430.

In the embodiment of the present application, the antenna ports configured on the antenna panels may be equally allocated, that is, the number of antenna ports allocated on each antenna panel may be the same, so that when the terminal device knows any one of the codebook configuration parameters listed below, the total number of antenna ports, the number of antenna panels, and the number of antenna ports included in each antenna panel may be determined.

Optionally, the codebook configuration parameter may include any one of:

a number of antenna port groups and a total number of antenna ports;

a total number of antenna ports and a number of antenna ports contained in each antenna port group; or,

Alternatively, the codebook configuration parameter may be configured in a higher layer signaling.

For example, the codebook indication information is configured in the RRC message.

Optionally, the method further comprises: in step 450, the network device may determine a precoding matrix according to the received PMI and RI, and precode downlink data to be sent.

Specifically, the network device may determine the precoding matrix W corresponding to the PMI according to the received PMI and RI, or perform mathematical transformation according to the precoding matrix W corresponding to the PMI, for example, may be a precoding matrix in an orthogonal subspace of W, and perform precoding on downlink data to be transmitted.

It should be understood that the specific method for the network device to determine the precoding matrix according to the received PMI and RI may be the same as the prior art, and a detailed description of the specific process is omitted here for brevity.

Optionally, the method 400 further comprises: step 460, the network device sends the precoded downlink data.

Correspondingly, in step 460, the terminal device receives the precoded downlink data.

In step 460, the network device may send the precoded downlink data to the terminal device, and may also send a precoded demodulation reference signal (DMRS), so that the terminal device determines an equivalent channel matrix according to the DMRS, and further demodulates the downlink data sent by the network device.

It should be understood that the processing procedure after the terminal device receives the downlink data may be the same as the prior art, and a detailed description of the specific procedure is omitted here for brevity.

The specific flow of the communication method according to the embodiment of the present application is described in detail above with reference to fig. 4, and the precoding matrix and the corresponding PMI feedback mechanism proposed in the present application will be described in detail below with reference to a specific example.

The embodiment of the application combines different rank values and the number of antenna panels, and providesA plurality of different precoding matrices. For convenience of explanation, it is assumed hereinafter that there are four antenna ports on each antenna panel, and there are two antenna ports in each polarization direction. Therefore, each antenna panel can form a beam vector of at most two polarization directions, denoted by b₁And b₂The beam vectors of the two polarization directions are mutually orthogonal. More specifically, b₁And b₂Are mutually orthogonal one-bit or two-dimensional DFT vectors with oversampling. Exemplarily, b₁And b₂Can be respectively as follows:

i_1,1、i_1,2for the index of the beam vector, it can be indicated by a PMI, N₁、N₂Number of antenna ports for different polarization directions, O₁、O₂E denotes a natural constant, and j denotes a unit imaginary number, which is an oversampling factor corresponding to antenna ports of different polarization directions.

Case one, rank M is 8, number of antenna port groups (i.e., antenna panel number) N is 2:

suppose the antenna polarization phase factor is c and the antenna port inter-group phase factor is

The embodiments of the present application provideThe basic form of the precoding matrix in the codebook corresponding to the rank can be expressed as:

or with the W₀A matrix having a row/column transformation relationship.

In the embodiment of the present application, the basic form refers to a precoding matrix that is subjected to a sorting deformation, such as a normalization process, on the basis of the basic form of the precoding matrix, and is also within the disclosure range of the precoding matrix in the codebook corresponding to the rank, which is provided in the embodiment of the present application, and it can be understood that the precoding matrix satisfies the above W₀The equation of (c). In the specific description, the "basic form" may be omitted, but since there is no substantial influence on the application of the precoding matrix by performing a permutation modification on the precoding matrix, such as a normalization process, and/or a row/column relation transformation, it should be understood that the precoding matrix obtained by performing a permutation modification on the precoding matrix, such as a normalization process, and/or a row/column relation transformation, is also within the disclosure range of the precoding matrix in the codebook corresponding to the rank proposed in the embodiments of the present application.

Such as:

the precoding matrix in the codebook corresponding to the rank may be W₀Or with the W₀A matrix having a row/column conversion relationship, or, W₀And a constant coefficient, e.g. constant coefficient

Or, with the W₀The product of a matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein, in order to distinguish different values of the phase factor among the same antenna port groups, the phase factor among the same antenna port groups is subjected to

Are respectively defined as

And

(n is more than or equal to 1, and n is an integer), wherein n is used for distinguishing different antenna port groups. The phase factors of the antenna ports corresponding to the same antenna port group are opposite numbers, so that the phase factors of the antenna ports in W are opposite numbers₀The inter-antenna port group phase factor corresponding to the antenna port group,

different embodiments are given below in connection with different quantization scenarios. It should be noted that the term "curing" is understood to mean that the parameter is fixed and the value thereof may be defined in the protocol; by "quantized" it is understood that the parameter is determined according to different channel states, and as the channel state changes, the parameter may change and need to be indicated by PMI feedback of the terminal device. In an embodiment of the present invention, the settable parameters include a polarization antenna phase factor and an antenna port inter-group phase factor, which may be taken from { +1, -1, + j, -j } regardless of whether or not set.

The details are as follows:

1) solidifying antenna port intergroup phase factor, quantizing polarized antenna phase factor

For the case of two antenna port groups, the inter-antenna port phase factor of one antenna port group may be 1, and the inter-antenna port phase factor of the other antenna port group may be two values opposite to each other, such as { +1, -1}, or { + j, -j }.

Then, the precoding matrix in the codebook corresponding to the rank may be any one of the following precoding matrices, or a matrix having a row/column transformation relationship with any one of the following precoding matrices, or the precoding matrix in the codebook corresponding to the rank may satisfy any one of the following precoding matrices, or a matrix having a row/column transformation relationship with any one of the following precoding matrices:

or

Or, W₄/W₅And a constant coefficient, e.g. constant coefficient

Or alternatively with W₄/W₅The product of a matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein c is a polarization antenna phase factor and takes the value in { +1, -1, + j, -j }. And c (d) e^jπd2And d is an index of a polarization antenna phase factor, which can be indicated by another PMI.

Specifically, the corresponding relationship between the value of d and c (d) can refer to the following table:

d	c(d)
		0	1
1	j
		2	-1
3	-j

it can be seen that in W₄And W₅In the middle, the upper two rows correspond to a first antenna port group, the lower two rows correspond to a second antenna port group, and the values of the phase factors among the antenna port groups are { +1, -1}, respectively. W₄Wherein the beam vectors corresponding to the antenna ports of the same layer in different antenna port groups are the same, such as W₄The beam vectors of the first column vector shown in (a) are all b₁；W₅Wherein the beam vectors corresponding to antenna ports in different antenna port groups of the same layer are different, e.g. W₅A first column vector shown therein corresponds to a beam vector of a first antenna port group of b₁The beam vector corresponding to the second antenna port group is b₂。

In this case, the PMI may include a first PMI indicating a DFT vector and a second PMI indicating a polarization antenna phase factor.

Alternatively, the PMIs include a first PMI and a tenth PMI. The first PMI is used for indicating a DFT vector, and the tenth PMI is used for indicating a polarized antenna phase factor.

Or, the PMIs include an eleventh PMI, where the eleventh PMI corresponds to multiple indication fields (e.g., includes multiple indication fields), and one of the indication fields is used to indicate a DFT vector, and another of the indication fields is used to indicate a polarized antenna phase factor.

In an embodiment of the present application, the first PMI may include an index i of a beam vector_1,1、i_1,2The second PMI may include an index d of a polarized antenna phase factor.

Optionally, step 430 specifically includes:

and the terminal equipment sends the first PMI, the second PMI and the RI to the network equipment according to the reference signal.

Or the terminal device sends the first PMI, the tenth PMI and the RI to the network device according to the reference signal.

Or, the terminal device sends the eleventh PMI and RI to the network device according to the reference signal.

2) Solidifying polarized antenna phase factor, quantizing phase factor between antenna port groups

The polarization antenna phase factor c may be taken in { +1, -1, + j, -j }, where c is assumed to be 1.

For the case of two antenna port groups, the inter-antenna port phase factor of one antenna port group may be 1, and the inter-antenna port phase factor of the other antenna port group may be two values opposite to each other, which are denoted as "opposite numbers" for convenience of distinction

And

and is

And is

Values can be taken from { +1, -1, + j, -j }.

Then, the precoding matrix in the codebook corresponding to the rank may be, or satisfy:

or with W₆A matrix having a row/column transformation relationship;

or, W₆And a constant coefficient, e.g. constant coefficient

Or alternatively with W₆The product of a matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

For the case of two antenna port groups, the inter-antenna port group phase factor of one antenna port group may be 1, and the inter-antenna port group phase factor of the other antenna port group may be two values that are opposite to each other. In the above-mentioned formula, the compound has the following structure,

and

is a phase factor between antenna port groups corresponding to the same antenna port group, and

and is

Values can be taken from { +1, -1, + j, -j }. And is

p is an index of the antenna port inter-group phase factor and can be indicated by PMI.

In particular, the value of p is

The correspondence can be referred to the following table:

in addition, in W₆In this embodiment, the beam vectors corresponding to the antenna ports in different antenna port groups of the same layer may be the same or different.

In this case, the PMIs may include a first PMI to indicate a DFT vector and a third PMI to indicate an antenna port inter-group phase factor. In an embodiment of the present application, the first PMI may include an index i of a beam vector_1,1、i_1,2The third PMI may include an index p of an antenna port inter-group phase factor.

Alternatively, the PMIs include a first PMI and a tenth PMI. The first PMI is used for indicating a DFT vector, and the tenth PMI is used for indicating an antenna port inter-group phase factor.

Or, the PMIs include an eleventh PMI, where the eleventh PMI corresponds to multiple indication fields (e.g., includes multiple indication fields), and one of the indication fields is used to indicate a DFT vector, and another of the indication fields is used to indicate an antenna port inter-group phase factor.

Optionally, step 420 specifically includes:

and the terminal equipment sends the first PMI, the third PMI and the RI to the network equipment according to the reference signal.

Or, the terminal device sends the first PMI, the tenth PMI and the RI to the network device according to the reference signal.

3) Simultaneous quantization of polarized antenna phase factors and antenna port interclass phase factors

The precoding matrix in the codebook corresponding to the rank may be, or satisfy:

or with W₁A matrix having a row/column transformation relationship;

or, W₁And a constant coefficient, e.g. constant coefficient

Or alternatively with W₁Moments with row/column conversion relationshipsThe product of an array and a constant coefficient, e.g. constant coefficient

Where c is a polarization antenna phase factor, which may be taken from { +1, -1, + j, -j }, and c (d) ═ e^jπd2And d is an index of a polarization antenna phase factor, which can be indicated by one PMI.

And

for the inter-antenna port group phase factor,

and is

Values can be taken from { +1, -1, + j, -j }. And is

p is an index of the antenna port inter-group phase factor and can be indicated by another PMI.

In addition, in W₁In this embodiment, the beams corresponding to the antenna ports in different antenna port groups of the same layer may be the same or different.

In this case, the PMIs may include a first PMI, a second PMI, and a third PMI. Wherein, the first PMI is used for indicating a DFT vector, the second PMI is used for indicating a polarization antenna phase factor, and the third PMI is used for indicating an antenna port inter-group phase factor.

Alternatively, the PMIs may include a twelfth PMI and a third PMI, the twelfth PMI corresponds to (e.g., includes) a plurality of indication fields, one of the indication fields is used for indicating a DFT vector, another of the indication fields is used for indicating an antenna port inter-group phase factor, and the third PMI is used for indicating a polarized antenna phase factor.

Optionally, step 420 specifically includes:

and the terminal equipment transmits the first PMI, the second PMI, the third PMI and the RI according to the reference signal.

Or the terminal equipment sends the twelfth PMI, the third PMI and the RI to the network equipment according to the reference signal.

Alternatively, the PMIs may include a first PMI and a fourth PMI. Wherein, the first PMI is used for indicating a DFT vector, and the fourth PMI is used for indicating a polarized antenna phase factor and an antenna port inter-group phase factor.

In one possible design, two indices, namely, the polarization antenna phase factor and the antenna port inter-group phase factor, respectively, are indicated in the same PMI. That is, the first PMI may include an index i of a beam vector_1,1、i_1,2And the fourth PMI contains an index d of a polarization antenna phase factor and an index p between antenna port group phase factors. In another possible design, the polarization antenna phase factor and the antenna port inter-group phase factor may have a binding relationship, and when one of the polarization antenna phase factor and the antenna port inter-group phase factor is adopted, the other value may be determined according to the binding relationship, and at this time, the polarization antenna phase factor or the antenna port inter-group phase factor may be indicated in the one PMI. That is, the first PMI may include an index i of a beam vector_1,1、i_1,2The fourth PMI includes an index d of a polarization antenna phase factor or an index p of an antenna port inter-group phase factor.

Optionally, step 420 specifically includes:

and the terminal equipment transmits the first PMI, the fourth PMI and the RI according to the reference signal.

4) Quantizing polarization antenna phase factors or antenna port inter-group phase factors

By applying a precoding matrix W to the above₀The deformation can result in:

then, the rank corresponds to the pre-coding in the codebookThe code matrix may be or satisfy: w₃Or with W₃The precoding matrix has a matrix of row/column transformation relation, or W₃And a constant coefficient, e.g. constant coefficient

Or alternatively with W₃The precoding matrix has the product of a matrix of row/column transformation relationship and a constant coefficient, which may be, for example

Wherein z is₁＝1，z₂Is a polarized antenna phase factor, z₃、-z₃Is the inter-antenna port group phase factor, z₄Is the product of the phase factor of the polarized antenna and the phase factor between the antenna port groups.

Z is above₂、z₃And z₄Some or all of which may be cured or quantified.

If all are cured, then z₂、z₃And z₄All values are taken in { +1, -1, + j, -j }, and specific values can be fixed in advance in a protocol and do not need to be quantized through PMI.

If partially quantized, at least two cases may be included:

case a: z is a radical of formula_kThe value of { +1, -1, + j, -j } is, k is one or more of 2,3, and 4.

That is, z₂、z₃And z₄The value range of (a) is { +1, -1, + j, -j }, but the specific value can be indicated by PMI.

In this case, the PMIs may include a first PMI to indicate a beam vector and a fifth PMI to indicate one z-vector₂、z₃And z₄At least one of (a).

Wherein the first PMI may include an index i of a beam vector_1,1、i_1,2The fifth PMI may include a function for quantizing antenna phaseIndex d of the factor and index p of the antenna port inter-group phase factor.

Optionally, step 420 specifically includes:

and the terminal equipment transmits the first PMI, the fifth PMI and the RI according to the reference signal.

Or, the plurality of z_kThe value of (a) may also be indicated by multiple PMIs, that is, multiple indexes are carried in multiple PMIs.

Case B: z is a radical of_m＝x_m×y_m，x_mAnd y_mIs z_mTwo components of (a). In particular, x_mThe representation corresponds to z_mAnd a wideband-related component, y_mIs expressed as corresponding to z_mAnd m takes the value of one or more of 2,3, and 4.

Wherein,

that is, z₂、z₃And z₄The values of (c) can be indicated by a wideband PMI and a subband PMI, respectively. The feedback mechanism can feed back CSI more accurately, and a more accurate precoding matrix can be determined to be matched with the channel state.

In this case, the PMIs may include a first PMI for indicating beam vectors, sixth PMIs each for indicating one x, and seventh PMIs_mEach seventh PMI is used to indicate a y_mThe value of (a).

Wherein the first PMI may include an index i of a beam vector_1,1、i_1,2The sixth PMI may include a second PMI indicating x_mThe seventh PMI may include a second index indicating y_mIs used to determine the index of (1). Optionally, step 420 specifically includes:

and the terminal equipment transmits the first PMI, the sixth PMI, the seventh PMI and the RI according to the reference signal.

Alternatively, the PMIs may include a seventh PMI and an eighth PMI,

wherein the seventh PMI may include a second PMI indicating y_mThe eighth PMI may include an index i of a beam vector_1,1、i_1,2And for indicating x_mIs used to determine the index of (1).

It should be understood that the above-listed quantization schemes and feedback mechanisms are only exemplary, and should not constitute any limitation to the present application, and the present application does not exclude the possibility of feeding back other PMIs for implementing the same or similar functions on the basis of using the precoding matrix provided in the present application and its mathematical variants. For example, the PMI may include only two PMIs for indicating any two of three factors, i.e., a beam vector, a polarization antenna phase factor, and an antenna port inter-group phase factor.

Case two, rank < 8, number of antenna port groups (i.e., antenna panel number) N ═ 2:

various possible precoding matrices for the case of rank M-8, and corresponding PMI feedback mechanisms, are shown above. In the case of rank M < 8, the precoding matrix in the codebook corresponding to the rank may include M column vectors, where the M column vectors are the precoding matrix W shown above₀、W₁、W₃、W₄、W₅And W₆Or a subset of column vectors in a matrix having a row/column transformation relationship with any of the above, or the M column vectors are the precoding matrix W shown above₀、W₁、W₃、W₄、W₅And W₆With a constant coefficient

Or the M column vectors are a subset of the column vectors in the product matrix of (a), or₀、W₁、W₃、W₄、W₅And W₆Has a matrix of row/column transformation relationship with constant coefficients

Is determined by the column vectors in the product matrix. Alternatively, the M column vectors are precoding matrices satisfying the above illustrationW₀、W₁、W₃、W₄、W₅And W₆Or a subset of column vectors in a matrix having a row/column transformation relationship with any of the above, or the M column vectors are the M column vectors satisfying the precoding matrix W shown above₀、W₁、W₃、W₄、W₅And W₆With a constant coefficient

Or the M column vectors are satisfied with the precoding matrix W₀、W₁、W₃、W₄、W₅And W₆Has a matrix of row/column transformation relationship with constant coefficients

Is determined by the column vectors in the product matrix.

Taking M as 5 as an example, the precoding matrix in the codebook corresponding to the rank includes 5 column vectors, and the 5 column vectors may be the W mentioned above₀、W₁、W₃、W₄、W₅And W₆Any 5 column vectors in any one precoding matrix, and the 5 column vectors may also be subjected to row/column transformation, or the 5 column vectors may be the above W column vectors₀、W₁、W₃、W₄、W₅And W₆Multiplying any one precoding matrix by a constant coefficient

5 column vectors in the formed precoding matrix (alternatively, the 5 column vectors may be the above-mentioned W₀、W₁、W₃、W₄、W₅And W₆Multiplying any 5 column vectors in any one precoding matrix by a constant coefficient

Formed precoding5 column vectors included in the matrix), or the 5 column vectors may be the above-mentioned W₀、W₁、W₃、W₄、W₅And W₆Any one of the pre-coding matrixes is subjected to row/column transformation and multiplied by a constant coefficient

5 column vectors in the formed precoding matrix (alternatively, the 5 column vectors may be the above-mentioned W₀、W₁、W₃、W₄、W₅And W₆Any 5 column vectors in any one precoding matrix are subjected to row/column transformation and multiplied by a constant coefficient

5 column vectors comprised by the formed precoding matrix).

In addition, the quantization scheme and the feedback mechanism listed in the first case are also applicable to the second case, and are not described herein again to avoid repetition.

Case three, rank is 8, number of antenna port groups N is 4:

The basic form of the precoding matrix in the codebook corresponding to the rank proposed in the embodiment of the present application may be expressed as:

or with the above-mentioned W₂A matrix having a row/column transformation relationship.

Such as:

the precoding matrix in the codebook corresponding to the rank may be W₂Or with the above-mentioned W₂A matrix having a row/column conversion relationship, or, W₂And a constant coefficient, e.g. constant coefficient

Or, with the W₂The product of a matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Are respectively defined as

And

(n is more than or equal to 1, and n is an integer), wherein n is used for distinguishing different antenna port groups. At W₂In (1),

and with

And

and

the phase factors between the three groups of antenna ports which are in one-to-one correspondence with the three groups of antenna ports are three groups of antenna ports, and two values of the phase factors between each group of antenna ports in the phase factors between any two groups of antenna ports are mutually opposite numbers. In other words, any two sets of antennasThe value of the phase factor between the port groups satisfies

The value of the phase factor between the other antenna port group satisfies

i is 1,2 or 3. For example, assuming that the absolute value of the inter-antenna port phase factor is 1, W₂The value of the phase factor between two antenna port groups in the antenna array can be { +1, +1, +1, +1, +1, +1, +1}, and the value of the phase factor between the other two antenna port groups can be { +1, +1, +1, -1, -1, -1, -1 }.

Or, assuming that the antenna polarization phase factor is c, the basic form of the precoding matrix in the codebook corresponding to the rank proposed in the embodiment of the present application may be represented as:

or with the above-mentioned W₂' a matrix having a row and/or column transformation relationship.

Such as:

the precoding matrix in the codebook corresponding to the rank may be W₂', or, with W described above₂' matrix having a row/column conversion relationship, or, W₂' and a constant coefficient, e.g. constant coefficient may be

Or, with the W₂' multiplication of a matrix having a row/column transformation relationship and a constant coefficient, e.g. constant coefficient

Wherein b is₁、b₂For the discrete fourier transform, DFT, vector, c for the polarized antenna phase factor,

Wherein the two parameters of 1 and the two parameters of-1 can be pre-stored in the respective devices via protocol definitions. The terminal device can also be configured through the network device.

Alternatively, α₁₁，α₁₂，α₁₃，α₁₄，α₂₁，α₂₂，α₂₃，α₂₄，β₁₁，β₁₂，β₁₃，β₁₄，β₂₁，β₂₂，β₂₃，β₂₄May correspond to an antenna port inter-group phase factor.

In the embodiment of the present invention, the antenna polarization phase factor c may be arbitrarily set to { +1, -1, + j, -j }, and the antenna port inter-group phase factor may also be arbitrarily set to { +1, -1, + j, -j }.

By applying a precoding matrix W to the above₂The deformation can result in:

or

Then, the precoding matrix in the codebook corresponding to the rank may be, or satisfy: w is a group of₇Or with the W₇With a rowA matrix of/column transform relations, or W₇And a constant coefficient, e.g. constant coefficient

Or, with the W₇The product of a matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein,

and

respectively, are phase factors between antenna port groups,

and is

And

all can take values in { +1, -1, + j, -j }. And is

p is the index of the antenna port inter-group phase factor.

With reference to the various quantization schemes and PMI feedback mechanisms listed in case one above, case three may also incorporate W₂A similar quantization scheme and corresponding feedback mechanism is employed. For example:

1) solidifying phase factors among antenna port groups, quantizing the phase factors of the polarized antennas:

the PMIs may include a first PMI for indicating a beam vector and a second PMI for indicating a polarized antenna phase factor;

or the PMIs may include an eleventh PMI corresponding to a plurality of indication fields (e.g., including a plurality of indication fields), where one indication field is used for indicating a beam vector and another indication field is used for indicating a polarized antenna phase factor.

2) Solidifying the phase factor of the polarized antenna, quantizing the phase factor between antenna port groups:

the PMIs may include a first PMI for indicating a beam vector and a third PMI for indicating an antenna port inter-group phase factor;

or the PMIs may include an eleventh PMI corresponding to a plurality of indication fields (e.g., including a plurality of indication fields), where one indication field is used for indicating a beam vector and another indication field is used for indicating an antenna port inter-group phase factor.

3) And simultaneously quantizing the phase factors of the polarized antennas and the phase factors between the antenna port groups:

the PMIs may include a first PMI for indicating a beam vector, a second PMI for indicating a polarization antenna phase factor, and a third PMI for indicating an antenna port inter-group phase factor; alternatively, the PMIs may include a first PMI for indicating a beam vector and a fourth PMI for indicating a polarized antenna phase factor and an antenna port inter-group phase factor.

Alternatively, the PMIs may include a twelfth PMI and a third PMI, the twelfth PMI corresponds to a plurality of indication fields, one of the indication fields is used for indicating a beam vector, another of the indication fields is used for indicating an antenna port inter-group phase factor, and the third PMI is used for indicating a polarization antenna phase factor.

It should be understood that the above-listed quantization schemes and feedback mechanisms are only exemplary, and should not constitute any limitation to the present application, and the present application does not exclude the possibility of feeding back other PMIs for implementing the same or similar functions based on the precoding matrix provided by the present application and its mathematical variants. For example, the PMI may include only two PMIs for indicating any two of three factors, i.e., a beam vector, a polarization antenna phase factor, and an antenna port inter-group phase factor.

Case four, rank < 8, number of antenna port groups N is 4:

various possible precoding matrices for the case of rank M-8, and corresponding PMI feedback mechanisms, are shown above. In the case of rank M < 8, the precoding matrix in the codebook corresponding to the rank may include M column vectors, where the M column vectors are the precoding matrix W shown above₂,W₂' and W₇Or a subset of column vectors in a matrix having a row/column transformation relationship with any of the above, or the M column vectors are the precoding matrix W shown above₂,W₂' and W₇With a constant coefficient

Or the M column vectors are a subset of the precoding matrix W shown above₂,W₂' and W₇Has a matrix of row/column transformation relationship with constant coefficients

A subset of column vectors in the matrix of products of (c). Alternatively, the M column vectors are precoding matrices W satisfying the above illustration₂,W₂' and W₇Or a subset of column vectors in a matrix having a row/column transformation relationship with any of the above, or the M column vectors are the M column vectors satisfying the precoding matrix W shown above₂,W₂' and W₇With a constant coefficient

Or the M column vectors are a subset of the column vectors in the product matrix satisfying the precoding matrix W shown above₂,W₂' and W₇Has a matrix of row/column transformation relationship with constant coefficients

A subset of column vectors in the matrix of products of (c).

In addition, the quantization scheme and the feedback mechanism listed in case three are also applicable to case two, and are not described here again to avoid repetition.

Case five, rank 3 or 4, and number of antenna port groups (i.e., antenna panel number) N2

The network device may configure codebook mode 1 or codebook mode 2 using higher layer signaling.

Optionally, codebook mode 1 and codebook mode 2 may correspond to different precoding matrix forms.

When configuring codebook mode 1, the basic form of the precoding matrix in the codebook corresponding to rank 4 can be expressed as:

or with W₈A matrix having row and/or column transformation relationships.

Such as:

the precoding matrix in the codebook corresponding to the rank may be W₈Or with the W₈A matrix having a row/column conversion relationship, or, W₈And a constant coefficient, e.g. constant coefficient

Or, with the W₈The product of a matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein, the equation after the first equal sign is used for description,

the phase factor of the polarized antenna can be { +1, -1, +j, -j, and n is a value in {0,1,2,3 };

and

for the inter-antenna port group phase factor,

can take the value p in { +1, -1, + j, -j { (R) }₁The value of (a) is the value in {0,1,2,3 }; the precoding matrix in the codebook corresponding to rank 3 contains 3 column vectors, which are the precoding matrix W in the codebook of rank 4 shown above₈Or either one of W and W₈A subset of column vectors in a matrix having a row and/or column transformation relationship, or W₈And a subset of column vectors in a product matrix of constant coefficients, e.g. constant coefficients may be

Or alternatively with W₈A subset of column vectors in a product matrix having a row and/or column transformation relationship and a constant coefficient, e.g. constant coefficient

Alternatively, the 3 column vectors are precoding matrices W in a codebook satisfying rank 4 shown above₈Or either one of W and W₈A subset of column vectors in a matrix having a row and/or column transformation relationship, or the 3 column vectors are such that W is satisfied₈And a subset of column vectors in a product matrix of constant coefficients, e.g. constant coefficients may be

Alternatively, the 3 column vectors are such that₈A subset of column vectors in a product matrix having a row and/or column transformation relationship and a constant coefficient, e.g. constant coefficient

In this case, the PMIs may include a thirteenth PMI and a third PMI. Wherein, the thirteenth PMI can be used to indicate an antenna port inter-group phase factor

The third PMI is used for indicating a phase factor of the polarized antenna

Alternatively, the PMIs may include a fourteenth PMI. Wherein the fourteenth PMI may be used to indicate

And

for example, the fourteenth PMI may include a plurality of indication fields, wherein one of the indication fields is used for indicating

Another indication field for indicating

When codebook mode 2 is configured, the basic form of the precoding matrix in the codebook corresponding to rank 4 can be expressed as:

or with W₉A matrix having a row/column transformation relationship.

For example,

the precoding matrix in the codebook corresponding to the rank may be W₉Or with the W₉A matrix having a row/column conversion relationship, or, W₉And a constant coefficient, e.g. constant coefficient

Or, with the W₉The product of a matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein,

Has a value of

p₁The value of (a) is the value in {0,1,2,3 };

has a value of

p₂The value of (a) is the value in {0,1,2,3 }; b_n1Has a value of

n₁Is the value in {0,1 }; b_n2Has a value of

n₂Is the value in {0,1 }; the precoding matrix in the codebook corresponding to rank 3 contains 3 column vectors, which are the precoding matrix W in the codebook of rank 4 shown above₉Or either one of W and W₉A subset of column vectors in a matrix having a row/column transformation relationship, or W₉And a subset of column vectors in a product matrix of constant coefficients, e.g. constant coefficients may be

Or alternatively with W₉A subset of column vectors in a product matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Alternatively, the 3 column vectors are precoding matrices W in a codebook satisfying rank 4 shown above₉Or either one of W and W₉A subset of column vectors in a matrix having a row/column transformation relationship, or 3 column vectors satisfying W₉And a subset of column vectors in a product matrix of constant coefficients, e.g. constant coefficients may be

Or, the 3 column vectors are such that₉A subset of column vectors in a matrix having a row/column transformation relationship and a product matrix of constant coefficients, e.g. constant coefficients

In this case, the PMIs may include a fifteenth PMI and a sixteenth PMI. Wherein the fifteenth PMI may be used to indicate

And

for example, the fifteenth PMI may contain a plurality of indication fields, wherein one of the indication fields is used for indicating

Another indication field for indicating

A sixteenth PMI for indicating a polarized antenna phase factor

And

and

for example, the sixteenth PMI may contain a plurality of indication fields, one of which is used for indicating

An indication field for indicating

Another indication field for indicating

Case six, rank 3 or 4, and number of antenna port groups (i.e., antenna panel number) N4

Alternatively, the network device may configure codebook mode 1 using higher layer signaling,

the basic form of the precoding matrix in the codebook corresponding to rank 4 may be:

wherein, the equation after the first equal sign is used for description,

for the inter-antenna port group phase factor,

can be between { +1, -1, + jValue of-j, p₁Is the value in {0,1,2,3 };

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

can be taken from { +1, -1, + j, -j }, p₂The value of (a) is the value in {0,1,2,3 };

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

can be taken from { +1, -1, + j, -j }, p₃Is the value in {0,1,2,3 }. The precoding matrix in the codebook corresponding to rank 3 contains 3 column vectors, which are the precoding matrix W in the codebook of rank 4 shown above₁₀Or either one of W and W₁₀A subset of column vectors in a matrix having a row/column transformation relationship, or W₁₀And a subset of column vectors in a product matrix of constant coefficients, e.g. constant coefficients may be

Or alternatively with W₁₀A subset of column vectors in a matrix having a row/column transformation relationship and a product matrix of constant coefficients, e.g. constant coefficients

Alternatively, the 3 column vectors are precoding matrices W in a codebook satisfying rank 4 shown above₁₀Or any one of the above with W₁₀A subset of column vectors in a matrix having a row/column transformation relationship, or 3 column vectors satisfying W₁₀And a subset of column vectors in a product matrix of constant coefficients, e.g. constant coefficients may be

Or, the 3 column vectors are such that₁₀A subset of column vectors in a matrix having a row/column transformation relationship and a product matrix of constant coefficients, e.g. constant coefficients

Or

Or with the above-mentioned W₁₀A matrix having a row/column transformation relationship.

Such as:

the precoding matrix in the codebook corresponding to the rank may be W₁₀Or with the W₁₀A matrix having a row/column conversion relationship, or, W₁₀And a constant coefficient, e.g. constant coefficient

Or, with the W₁₀The product of a matrix having a row/column transformation relationship and a constant coefficient, e.g. the constant coefficient may be

Wherein alpha is₁，α₂，α₃，α₄Two of the values are +1, and the other two values are-1; beta is a₁，β₂，β₃，β₄Two values are +1, and the other two values are-1；

Wherein, the equation after the first equal sign is used for description,

the phase factor of the polarized antenna can be taken from { +1, -1, + j, -j }, and the value of n is taken from {0,1,2,3 };

is the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

for the inter-antenna port group phase factor,

can take the value p in { +1, -1, + j, -j { (R) }₃Is the value in {0,1,2,3 }. The precoding matrix in the codebook corresponding to rank 3 contains 3 column vectors, which are the precoding matrix W in the codebook of rank 4 shown above₁₀Or any one of the above with W₁₀A subset of column vectors in a matrix having a row/column transformation relationship, or W₁₀And a subset of column vectors in a product matrix of constant coefficients, e.g. constant coefficients may be

Alternatively, the 3 column vectors are precoding matrices W in a codebook satisfying rank 4 shown above₁₀Or either one of W and W₁₀A subset of column vectors in a matrix having a row/column transformation relationship, or 3 column vectors satisfying W₁₀And a subset of column vectors in a product matrix of constant coefficients, e.g. constant coefficients may be

Or, the 3 column vectors are such that₁₀Subsets of column vectors in a matrix having a row/column transformation relationship and a product matrix of constant coefficients, for exampleE.g. the constant coefficient may be

In case six, the PMIs may include a seventeenth PMI and a third PMI. Wherein the seventeenth PMI may be used to indicate

And

for example, the seventeenth PMI may include a plurality of indication fields, wherein one of the indication fields is used for indicating

Another indication field for indicating

There is also an indication field for indicating

The third PMI is used for indicating a phase factor of the polarized antenna

Alternatively, the PMIs may include an eighteenth PMI. Wherein the eighteenth PMI can be used to indicate

And

for example, the eighteenth PMI may containA plurality of indication fields, wherein one indication field is used for indicating

Another indication field for indicating

Another indication field for indicating

There is also an indication field for indicating

Therefore, in the embodiment of the present application, the network device and the terminal device determine the CSI based on the precoding matrix in the high-order codebook provided by the present application, so that transmission of a data stream with a larger number of layers can be achieved. Therefore, the method is beneficial to improving the speed of MIMO transmission, improving the data transmission capability of the communication system and improving the throughput.

It should be understood that the above listed precoding matrices are only possible forms of precoding matrices provided in the present application, and should not constitute any limitation to the present application, and precoding matrices obtained by performing row/column transformation or other mathematical transformation on the forms of precoding matrices provided in the present application should fall within the protection scope of the present application.

It should be noted that, in one possible implementation, the network device and the terminal device may store one or more of the following:

a) the method and the device are used for obtaining parameters in any precoding matrix listed in each implementation manner, and any precoding matrix can be obtained based on the parameters. For example, the parameters may include, but are not limited to, the above listed codebook configuration parameters, and the like;

b) any of the precoding matrices listed in the above implementations;

c) a matrix expanded based on any one of the precoding matrices listed in the above-described implementation manners;

d) a matrix obtained by row/column transformation of any one of the precoding matrices listed in the above implementation modes;

e) the matrix is an extended matrix based on a matrix obtained by row/column transformation of any precoding matrix listed in the above-described implementation modes.

f) A codebook comprising at least one matrix as described in b), c), d) or e) above.

It should be understood that in this application, a row/column transform refers to a row transform, or a column transform, or both a row transform and a column transform.

The term "store" as referred to herein may refer to a store in one or more memories. The one or more memories may be provided separately or integrated in the encoder or decoder, the processor, or the communication device. The one or more memories may also be provided separately, with a portion of the one or more memories being integrated into the decoder, the processor, or the communication device. The type of memory may be any type of storage medium, and the application is not limited thereto.

The communication method according to the embodiment of the present invention is described in detail above with reference to fig. 4, and the communication method according to another embodiment of the present invention is described in detail below with reference to fig. 5.

Fig. 5 is a schematic flow chart of a communication method provided by the embodiment of the present application, which is shown from the perspective of device interaction. In particular, fig. 5 shows a scenario of uplink channel measurement. As shown, the method shown in fig. 5 may include steps 510 to 550.

In step 510, the terminal device transmits a reference signal to the network device.

In step 520, the network device sends the PMI and RI to the terminal device according to the reference signal.

Optionally, the method 500 further comprises: in step 530, the network device sends codebook indication information to the terminal device.

Optionally, the method 500 further comprises: in step 540, the network device sends codebook configuration information to the terminal device.

Optionally, the method 500 further comprises: and step 550, the terminal device performs precoding on the uplink data to be sent according to the PMI and the RI, and sends the precoded uplink data.

It should be understood that the steps in method 500 are similar to the steps in method 400 and are not described in detail herein to avoid repetition.

The above-mentioned numbering of the steps does not limit the sequence of the steps, and the sequence of the steps can be determined according to the implementation of the scheme. For example, step 530 may precede step 540 or follow step 540.

The various forms of precoding matrices described above in connection with fig. 4 are equally applicable to uplink channel measurements. For the avoidance of repetition, a detailed description of the precoding matrix will not be provided herein.

In addition, in this embodiment of the application, after the network device obtains the CSI of the uplink channel by measurement, the CSI of the downlink channel may also be determined according to channel reciprocity (for example, in Time Division Duplexing (TDD)). This is not particularly limited in the present application.

Fig. 6 is a schematic diagram of a device 10 for communication according to the foregoing method, as shown in fig. 6, the device 10 may be a terminal device, or may be a chip or a circuit, for example, a chip or a circuit that may be disposed on a terminal device. The terminal device may correspond to the terminal device in the method.

The apparatus 10 may include a processor 11 and a memory 12. The memory 12 is configured to store instructions, and the processor 11 is configured to execute the instructions stored by the memory 12 to enable the apparatus 20 to implement the steps in the corresponding method as in fig. 4 or fig. 5.

Further, the device 10 may also include an input port 13 and an output port 14. Further, the processor 11, the memory 12, the input port 13 and the output port 14 may communicate with each other via internal connection paths, passing control and/or data signals. The memory 12 is used for storing a computer program, and the processor 11 may be used for calling and running the computer program from the memory 12 to control the input port 13 to receive a signal and the output port 14 to send a signal, so as to complete the steps of the terminal device in the above method. The memory 12 may be integrated in the processor 11 or may be provided separately from the processor 11.

Alternatively, if the device 10 is a terminal, the input port 13 is a receiver and the output port 14 is a transmitter. Wherein the receiver and the transmitter may be the same or different physical entities. When the same physical entity, may be collectively referred to as a transceiver.

Alternatively, if the device 10 is a chip or a circuit, the input port 13 is an input interface, and the output port 14 is an output interface.

As an implementation manner, the functions of the input port 13 and the output port 14 may be implemented by a transceiver circuit or a dedicated chip for transceiving. The processor 11 may be considered to be implemented by a dedicated processing chip, processing circuitry, a processor, or a general purpose chip.

As another implementation manner, a manner of using a general-purpose computer to implement the terminal device provided in the embodiment of the present application may be considered. Program codes that will implement the functions of the processor 11, the input port 13 and the output port 14 are stored in the memory 12, and a general-purpose processor implements the functions of the processor 11, the input port 13 and the output port 14 by executing the codes in the memory 12.

For the concepts, explanations, details and other steps related to the technical solutions provided in the embodiments of the present application related to the apparatus 10, reference is made to the descriptions of the foregoing methods or other embodiments, which are not repeated herein.

Fig. 7 is a schematic structural diagram of a terminal device 20 provided in the present application. The terminal device 20 is applicable to the system shown in fig. 1. For convenience of explanation, fig. 7 shows only main components of the terminal device. As shown in fig. 7, the terminal device 20 includes a processor, a memory, a control circuit, an antenna, and an input-output means.

The processor is mainly configured to process a communication protocol and communication data, control the entire terminal device, execute a software program, and process data of the software program, for example, to support the terminal device to perform the actions described in the above embodiment of the method for indicating a transmission precoding matrix. The memory is mainly used for storing software programs and data, for example, the codebook described in the above embodiments. The control circuit is mainly used for converting baseband signals and radio frequency signals and processing the radio frequency signals. The control circuit and the antenna together, which may also be called a transceiver, are mainly used for transceiving radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc., are used primarily for receiving data input by a user and for outputting data to the user.

When the terminal device is turned on, the processor can read the software program in the storage unit, interpret and execute the instruction of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor outputs a baseband signal to the radio frequency circuit after performing baseband processing on the data to be sent, and the radio frequency circuit performs radio frequency processing on the baseband signal and sends the radio frequency signal outwards in the form of electromagnetic waves through the antenna. When data is sent to the terminal equipment, the radio frequency circuit receives radio frequency signals through the antenna, converts the radio frequency signals into baseband signals and outputs the baseband signals to the processor, and the processor converts the baseband signals into the data and processes the data.

Those skilled in the art will appreciate that fig. 7 shows only one memory and processor for the sake of illustration. In an actual terminal device, there may be multiple processors and memories. The memory may also be referred to as a storage medium or a storage device, and the like, which is not limited in this application.

As an alternative implementation manner, the processor may include a baseband processor and a central processing unit, where the baseband processor is mainly used to process a communication protocol and communication data, and the central processing unit is mainly used to control the whole terminal device, execute a software program, and process data of the software program. The processor in fig. 7 integrates the functions of the baseband processor and the central processing unit, and those skilled in the art will understand that the baseband processor and the central processing unit may also be independent processors, and are interconnected through a bus or the like. Those skilled in the art will appreciate that the terminal device may include a plurality of baseband processors to accommodate different network formats, the terminal device may include a plurality of central processors to enhance its processing capability, and various components of the terminal device may be connected by various buses. The baseband processor can also be expressed as a baseband processing circuit or a baseband processing chip. The central processing unit can also be expressed as a central processing circuit or a central processing chip. The function of processing the communication protocol and the communication data may be built in the processor, or may be stored in the storage unit in the form of a software program, and the processor executes the software program to realize the baseband processing function.

For example, in the embodiment of the present application, the antenna and the control circuit having the transceiving function may be regarded as the transceiving unit 201 of the terminal device 20, and the processor having the processing function may be regarded as the processing unit 202 of the terminal device 20. As shown in fig. 7, the terminal device 20 includes a transceiving unit 201 and a processing unit 202. A transceiver unit may also be referred to as a transceiver, a transceiving device, etc. Optionally, a device for implementing the receiving function in the transceiver 201 may be regarded as a receiving unit, and a device for implementing the transmitting function in the transceiver 201 may be regarded as a transmitting unit, that is, the transceiver 201 includes a receiving unit and a transmitting unit. For example, the receiving unit may also be referred to as a receiver, a receiving circuit, etc., and the sending unit may be referred to as a transmitter, a transmitting circuit, etc.

According to the foregoing method, fig. 8 is a second schematic diagram of the apparatus 30 for communication according to the embodiment of the present application, and as shown in fig. 8, the apparatus 30 may be a network device, or may be a chip or a circuit, such as a chip or a circuit that may be disposed in a network device. The network device corresponds to the network device in the method.

The apparatus 30 may include a processor 31 and a memory 32. The memory 32 is used for storing instructions, and the processor 31 is used for executing the instructions stored in the memory 32 to make the apparatus 30 implement the steps in the corresponding method as described in fig. 4 or fig. 5.

Further, the device 30 may also include an input port 33 and an output port 33. Still further, the processor 31, memory 32, input port 33 and output port 34 may communicate with each other via internal connection paths, passing control and/or data signals. The memory 32 is used for storing a computer program, and the processor 31 may be used for calling and running the computer program from the memory 32 to control the input port 33 to receive signals and the output port 34 to send signals, so as to complete the steps of the terminal device in the above method. The memory 32 may be integrated in the processor 31 or may be provided separately from the processor 31.

The steps of the network device in the above method are completed by receiving signals at the control input port 33 and sending signals at the control output port 34. The memory 32 may be integrated in the processor 31 or may be provided separately from the processor 31.

Alternatively, if the device 30 is a network device, the input port 33 is a receiver and the output port 34 is a transmitter. Wherein the receiver and the transmitter may be the same or different physical entities. When the same physical entity, may be collectively referred to as a transceiver.

Alternatively, if the device 30 is a chip or a circuit, the input port 33 is an input interface, and the output port 34 is an output interface.

Alternatively, if the apparatus 30 is a chip or a circuit, the apparatus 30 may not include the memory 32, and the processor 31 may read instructions (programs or codes) in the memory outside the chip to implement the functions in the corresponding methods as shown in fig. 4 or fig. 5.

As an implementation manner, the functions of the input port 33 and the output port 34 may be realized by a transceiver circuit or a dedicated chip for transceiving. The processor 31 may be considered to be implemented by a dedicated processing chip, processing circuitry, a processor, or a general purpose chip.

As another implementation manner, a manner of using a general-purpose computer to implement the network device provided in the embodiment of the present application may be considered. Program code that implements the functions of the processor 31, the input ports 33 and the output ports 34 is stored in memory, and a general-purpose processor implements the functions of the processor 31, the input ports 33 and the output ports 34 by executing the code in the memory.

For the concepts, explanations, details and other steps related to the technical solutions provided in the embodiments of the present application related to the apparatus 30, reference is made to the descriptions of the foregoing methods or other embodiments, which are not repeated herein.

Fig. 9 is a schematic structural diagram of a network device according to an embodiment of the present application, which may be used to implement the functions of the network device in the foregoing method. Such as a schematic diagram of the structure of the base station. As shown in fig. 9, the base station can be applied to the system shown in fig. 1. The base station 40 includes one or more radio frequency units, such as a Remote Radio Unit (RRU) 401 and one or more baseband units (BBUs) (also referred to as digital units, DUs) 402. The RRU 401 may be referred to as a transceiver unit, transceiver circuitry, or transceiver, etc., which may include at least one antenna 4011 and a radio frequency unit 4012. The RRU 401 is mainly used for transceiving radio frequency signals and converting radio frequency signals and baseband signals, for example, for sending signaling messages described in the above embodiments to a terminal device. The BBU 402 is mainly used for performing baseband processing, controlling a base station, and the like. The RRU 401 and the BBU 402 may be physically disposed together or may be physically disposed separately, that is, distributed base stations.

The BBU 402 is a control center of a base station, and may also be referred to as a processing unit, and is mainly used for performing baseband processing functions, such as channel coding, multiplexing, modulation, spreading, and the like. For example, the BBU (processing unit) 402 can be used to control the base station 40 to execute the operation flow related to the network device in the above-described method embodiment.

In an example, the BBU 402 may be formed by one or more boards, and the boards may support a radio access network of a single access system (e.g., an LTE system or a 5G system) together, or may support radio access networks of different access systems respectively. The BBU 402 further includes a memory 4021 and a processor 4022. The memory 4021 is used to store necessary instructions and data. For example, the memory 4021 stores the codebook and the like in the above-described embodiments. The processor 4022 is configured to control the base station to perform necessary actions, for example, to control the base station to execute the operation flow related to the network device in the above method embodiment. The memory 4021 and the processor 4022 may serve one or more boards. That is, the memory and processor may be provided separately on each board. Multiple boards may share the same memory and processor. In addition, each single board can be provided with necessary circuits.

In one possible implementation, with the development of System-on-chip (SoC) technology, all or part of the functions of the part 402 and the part 401 may be implemented by SoC technology, for example, by a base station function chip, which integrates a processor, a memory, an antenna interface, and other devices, and a program of the related functions of the base station is stored in the memory, and the processor executes the program to implement the related functions of the base station. Optionally, the base station function chip can also read a memory outside the chip to implement the relevant functions of the base station.

It should be understood that the structure of the base station illustrated in fig. 9 is only one possible form, and should not limit the embodiments of the present application in any way. This application does not exclude the possibility of other forms of base station structure that may appear in the future.

According to the method provided by the embodiment of the present application, an embodiment of the present application further provides a communication system, which includes the foregoing network device and one or more terminal devices.

It should be understood that in the embodiments of the present application, the processor may be a Central Processing Unit (CPU), and the processor may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It will also be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of Random Access Memory (RAM) are available, such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct bus RAM (DR RAM).

The above embodiments may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, the above-described embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product comprises one or more computer instructions or computer programs. The procedures or functions according to the embodiments of the present application are wholly or partially generated when the computer instructions or the computer program are loaded or executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains one or more collections of available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium may be a solid state disk.

It should be understood that the term "and/or" herein is merely one type of association relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a removable hard disk, a Read Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A communications apparatus, comprising:

a memory for storing a computer program;

a processor for executing the computer program stored in the memory to cause the apparatus to perform the steps of:

receiving a reference signal for channel measurement;

and sending a Precoding Matrix Indicator (PMI) and a Rank Indicator (RI) according to the reference signal, wherein the PMI is used for indicating a precoding matrix in a codebook corresponding to the RI, the precoding matrix in the codebook comprises a plurality of matrixes which are in one-to-one correspondence with a plurality of antenna port groups, the matrix corresponding to one antenna port group or each antenna port group in at least two antenna port groups has two different antenna port group-to-group phase factors, and any two column vectors in the precoding matrix are orthogonal to each other.

2. A communications apparatus, comprising:

a memory for storing a computer program;

transmitting a reference signal for channel measurement;

receiving a Precoding Matrix Indicator (PMI) and a Rank Indicator (RI), wherein the PMI and the RI are related to the reference signal, the PMI is used for indicating a precoding matrix in a codebook corresponding to the RI, the precoding matrix in the codebook comprises a plurality of matrixes in one-to-one correspondence with a plurality of antenna port groups, the matrix corresponding to one antenna port group or each antenna port group in at least two antenna port groups has two different antenna port group-to-group phase factors, and any two column vectors in the precoding matrix are orthogonal to each other.

3. The apparatus according to claim 1 or 2, wherein the number of columns of the precoding matrix corresponds to a rank, the number of rows of the precoding matrix corresponds to the total number of antenna ports, wherein the rank is M, the number of antenna port groups is N, and N/2 antenna port groups in the precoding matrix correspond to a matrix including a first column vector set and a second column vector set, the antenna port inter-group phase factors of the first column vector set and the antenna port inter-group phase factors of the second column vector set are opposite numbers, wherein M is an integer greater than 1, and N is an even number greater than or equal to 2.

4. The apparatus according to any of claims 1 to 3, wherein M is 8, N is 2, and the precoding matrix in the codebook corresponding to the rank is:

5. the apparatus according to any of claims 1-3, wherein M < 8, N is 2, and a precoding matrix in a codebook corresponding to the rank comprises M column vectors, wherein the M column vectors are a subset of column vectors in the following precoding matrices:

6. the apparatus according to any of claims 1 to 3, wherein M is 8, N is 4, and the precoding matrix in the codebook corresponding to the rank is:

wherein, b₁、b₂Is the DFT vector, c is the polarized antenna phase factor,

and

and

and

i is 1,2 or 3.

7. The apparatus according to any of claims 1-3, wherein M < 8, N is 4, and a precoding matrix in a codebook for rank mapping comprises M column vectors, wherein the M column vectors are a subset of column vectors in the following precoding matrices:

wherein, b₁、b₂Is the DFT vector, c is the polarized antenna phase factor,

and

and

and

The value of the phase factor between the other antenna port group satisfies

i is 1,2 or 3.

8. The apparatus according to any of claims 1-7, wherein the PMIs comprise a first PMI, a second PMI and/or a third PMI, the first PMI indicating a DFT vector, the second PMI indicating the antenna port inter-group phase factor, and the third PMI indicating a polarized antenna phase factor.

9. The apparatus according to any of claims 1-7, wherein the PMIs comprise a first PMI and a fourth PMI, the first PMI indicating a DFT vector, the fourth PMI indicating the antenna port inter-group phase factor and a polarization antenna phase factor.

10. The apparatus according to any of claims 1 to 3, wherein M is 8, N is 2, and the precoding matrix in the codebook corresponding to the rank is:

wherein, b₁、b₂Is a DFT vector, z₁＝1，z₂Is a polarized antenna phase factor, z₃、-z₃Is the inter-antenna port group phase factor, z₄Is the product of the phase factor of the polarized antenna and the phase factor between the antenna port groups.

11. The apparatus according to any of claims 1-3, wherein M < 8, N is 2, and a precoding matrix in a codebook corresponding to the rank comprises M column vectors, wherein the M column vectors are a subset of column vectors in the following precoding matrices:

12. Device according to claim 10 or 11, characterized in that z is_kThe value of (a) is a value in { +1, -1, + j, -j }, and the value of k is 2,3, 4.

13. The apparatus of claim 12, wherein the PMIs comprise a first PMI and a fifth PMI, wherein the first PMI is used for indicating DFT vectors, and wherein the fifth PMI is used for indicating z₂、z₃、z₄At least one of (a).

14. Device according to claim 10 or 11, characterized in that z is_m＝x_m×y_m，x_mAnd y_mIs z_mM takes on one or more of the values 2,3, 4.

15. The apparatus of claim 14, wherein the PMIs comprise a first PMI for indicating DFT vectors, a sixth PMI for indicating x, and a seventh PMI_mThe seventh PMI is used to indicate y_m。

16. Root of herbaceous plantThe apparatus of claim 14, wherein the PMIs comprise a seventh PMI and an eighth PMI, the seventh PMI being used to indicate y_mThe eighth PMI is used to indicate a DFT vector sum x_m。

17. A communication system comprising an apparatus as claimed in claim 1, or any one of claims 3 to 16 when dependent on claim 1 and/or an apparatus as claimed in claim 2, or any one of claims 3 to 16 when dependent on claim 2.