KR20140042723A - Method of device to device communication and apparatus thereof - Google Patents

Abstract

Disclosed is a device-to-device (D2D) communications method and apparatus. A communications method performed in a second device comprises the steps of: receiving first configuration information for receiving a reference signal and second configuration information for reporting channel state information from a base station; receiving the reference signal based on the first configuration information from a first device; generating the channel state information on a communications link between the first device and the second device based on the reference signal; and transmitting the channel state information based on the second configuration information to the base station. Therefore, the D2D communications can be performed effectively. [Reference numerals] (10) First base station; (11) First terminal; (20) Second base station; (21) Second terminal; (S100) CSI-SRS transmission configuration information; (S110) CSI-SRS reception configuration information D2D-CSI report configuration information; (S130) D2D-CSI generation; (S140) D2D-CSI report

Description

Method and device for direct communication between terminals {METHOD OF DEVICE TO DEVICE COMMUNICATION AND APPARATUS THEREOF}

The present invention relates to a direct communication technology between terminals, and more particularly, to a communication method and apparatus for effectively performing direct communication between terminals.

In a cellular communication environment, a general method by which terminals transmit and receive data is through a base station. That is, when there is data to be transmitted to the second terminal, the first terminal transmits the data to the first base station to which the first terminal belongs. The first base station transmits the data received from the first terminal to the second base station to which the second terminal belongs. Finally, the second base station transmits the data received from the first base station to the second terminal. Here, the first base station and the second base station may be the same base station or different base stations.

Meanwhile, device to device communication (D2D) means that terminals communicate directly without going through a base station. That is, the first terminal can directly communicate with the second terminal without going through the base station to transmit / receive data.

An object of the present invention for solving the above problems is to provide a direct communication method between terminals for reporting the channel state information for the direct communication link between terminals.

Another object of the present invention for solving the above problems is to provide a direct communication method between terminals for transmitting control information for direct communication between terminals.

In accordance with an aspect of the present invention, there is provided a communication method of a second terminal, the method comprising: receiving first configuration information for receiving a reference signal and second configuration information for reporting channel state information from a base station; Receiving a reference signal from the first terminal based on the first configuration information, generating channel state information on a communication link between the first terminal and the second terminal based on the reference signal; And transmitting the channel state information to the base station based on the 2 configuration information.

In the generating of the channel state information, channel state information including channel quality indicator information may be generated.

In the generating of the channel state information, when the transmission rank is 1 and one codeword is transmitted, channel quality indicator information for the one codeword is generated for the entire band in which the reference signal is transmitted. Can be.

In the generating of the channel state information, channel state information including rank indicator information may be generated.

The generating of the channel state information may generate rank indicator information for the entire band on which the reference signal is transmitted, based on at least one reference signal.

In the generating of the channel state information, channel state information including precoder matrix indicator information and channel quality indicator information may be generated.

In the generating of the channel state information, the precoder matrix indicator information and the channel quality indicator information may be generated based on the number of codewords and the transport layer determined according to the transmission rank.

The transmitting of the channel state information to the base station may include communication between the first terminal and the second terminal using a physical channel for transmitting channel state information on downlink between the base station and the second terminal. Channel state information for the link may be provided to the base station.

In the transmitting of the channel state information to the base station, a transmission period and an offset different from a physical channel for transmitting channel state information for downlink between the base station and the second terminal may be used.

The communication method of the first terminal according to an embodiment of the present invention for achieving the another object, generating data indicator information indicating whether the at least one codeword is transmitted to the second terminal; And transmitting a physical shared channel including data indicator information and D2D data to the second terminal, and receiving a physical control channel, which is a response of the physical shared channel, from the second terminal.

Here, the physical shared channel may further include D2D control information having power control command information for the physical control channel.

Here, the physical control channel may include power control command information for a physical shared channel.

Herein, the data indicator information may be allocated to both symbols adjacent to a symbol where a demodulation reference signal is located in the physical shared channel.

Here, the data indicator information may be allocated to both symbols adjacent to the symbol where the demodulation reference signal is located in the physical shared channel, and the D2D control information may be allocated to a symbol adjacent to the symbol where the data indicator information is located.

According to another aspect of the present invention, there is provided a communication method of a first terminal, the method comprising: generating D2D control information including control information transmitted to the second terminal through a physical control channel; And transmitting a physical shared channel including control information and D2D data to the second terminal.

Here, in the generating of the D2D control information, if simultaneous transmission of a physical control channel and a physical shared channel for the second terminal is not allowed, response information for data reception and power control command information for the physical shared channel The D2D control information including may be generated.

The generating of the D2D control information may include response information for data reception, power control command information for a physical shared channel, when simultaneous transmission of a physical control channel and a physical shared channel for the second terminal is permitted. The D2D control information including power control command information for a physical control channel may be generated.

Here, the physical shared channel may further include data indicator information indicating whether the at least one codeword transmitted to the second terminal is super-transmitted.

Herein, the data indicator information may be allocated to both symbols adjacent to a symbol where a demodulation reference signal is located in the physical shared channel.

Here, the data indicator information may be allocated to both symbols adjacent to the symbol where the demodulation reference signal is located in the physical shared channel, and the D2D control information may be allocated to a symbol adjacent to the symbol where the data indicator information is located.

According to the present invention, direct communication between terminals can be effectively performed.

1 is a conceptual diagram illustrating an embodiment of direct communication between terminals.
2 is a conceptual diagram illustrating another embodiment of direct communication between terminals.
3 is a flowchart illustrating a direct communication method between terminals according to an embodiment of the present invention.
4 is a flowchart illustrating a direct communication method between terminals according to another embodiment of the present invention.
5 is a conceptual diagram illustrating an embodiment of a configuration of a D2D-PSCH.
6 is a conceptual diagram illustrating another embodiment of the configuration of the D2D-PSCH.
7 is a conceptual diagram illustrating another embodiment of the configuration of the D2D-PSCH.
8 is a flowchart illustrating a direct communication method between terminals according to another embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

Throughout the specification, the network can be, for example, a wireless Internet such as WiFi (Wireless Fidelity), a WiBro (Wireless Broadband Internet) or a WiMax (World Interoperability for Microwave Access) A 3G mobile communication network such as a Wideband Code Division Multiple Access (WCDMA) or CDMA2000, a High Speed Downlink Packet Access (HSDPA) or a High Speed Uplink Packet Access (HSUPA) 3.5G mobile communication network, and 4G mobile communication network such as LTE (Long Term Evolution) network or LTE-Advanced network.

In addition, the base station in the entire specification may mean a control device that controls one cell. A physical base station in an actual wireless communication system can control a plurality of cells, in which case the physical base station can be considered to include multiple base stations. That is, parameters assigned differently for each cell can be regarded as being allocated to different values by each base station.

Here, the base station includes an access point, a radio access station, a node B, an evolved Node B, a base transceiver station, an MMR A BS, an access point, a radio access station, a Node B, an eNodeB, a base transceiver station, an MMR-BS, and the like.

Also, throughout the specification, a terminal may be referred to as a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, A terminal, a mobile station, a mobile station, a subscriber station, a mobile subscriber station, a user equipment, an access terminal, and the like.

Here, a desktop computer, a laptop computer, a tablet PC, a wireless phone, a mobile phone, a smart phone, an e- a book reader, a portable multimedia player (PMP), a portable game machine, a navigation device, a digital camera, a digital multimedia broadcasting (DMB) player, a digital audio recorder, A digital picture recorder, a digital picture player, a digital video recorder, a digital video player, or the like can be used.

1 is a conceptual diagram illustrating an embodiment of direct communication between terminals.

Referring to FIG. 1, the first terminal 11 and the second terminal 21 may perform device to device communication (D2D), and the first terminal 11 and the second terminal 21. ) Is located within the cell range of the first base station 10. Each terminal 11 and 21 may transmit and receive information for direct communication between terminals with the first base station 10.

2 is a conceptual diagram illustrating another embodiment of direct communication between terminals.

Referring to FIG. 2, the first terminal 11 and the second terminal 21 may perform direct communication between the terminals, and the first terminal 11 is located within a cell range of the first base station 10. The second terminal 21 is located within the cell range of the second base station 20. The first terminal 11 may transmit and receive information for direct communication between terminals with the first base station 10, and the second terminal 21 may transmit and receive information for direct communication between the terminals with the second base station 20. can do.

The first base station 10 and the second base station 20 may be connected to the central China 30. The centralized China 30 may collect information transmitted from each of the base stations 10 and 20 and control direct communication between terminals based on the information. The central station 30 may be separate from the base station, or may be within the base station.

Comparing the case where two terminals performing direct communication between terminals belong to the same base station and different base stations, the first terminal 11 transmits and receives information for direct communication between the first base station 10 and the terminal. The same is true in that the first terminal 11 and the second terminal 21 transmit and receive information with each other. Although the subject (1st base station 10 or the 2nd base station 20) which transmits and receives information with the 2nd terminal 21 differs from each other, the 2nd terminal 21 transmits and receives with the 1st base station 10. FIG. Information to be transmitted and the information transmitted and received by the second terminal 21 and the second base station 20 may be the same. As a result, in the direct communication between terminals, the information transmitted and received by the terminal and the terminal and the information transmitted and received by the terminal and the base station may be regarded as the same when both the terminal belongs to the same base station and different base stations.

In the following embodiment, the description will be made based on direct communication between two terminals belonging to different base stations, but unless otherwise specified, the present invention may also be applied to direct communication between two terminals belonging to the same base station.

In the terminal-to-terminal direct communication, the terminal-to-terminal direct communication may be classified according to a duplex method of a link from the first terminal to the second terminal and a link from the second terminal to the first terminal. Direct communication between terminals in which the link from the first terminal to the second terminal and the link from the second terminal to the first terminal uses the same frequency band and is divided by time may be defined as direct communication between time division terminals. Direct communication between terminals in which the link from the first terminal to the second terminal and the link from the second terminal to the first terminal uses different frequency bands and is divided into frequencies may be defined as direct communication between frequency division terminals.

When the communication between the terminal and the base station is a time division duplex (TDD), the direct communication between the time division terminals may use only an uplink subframe among the frequency bands used in the communication between the terminal and the base station. Alternatively, only downlink subframes may be used, or both uplink and downlink subframes may be used.

When the communication between the terminal and the base station is a frequency division duplex (FDD), the direct communication between the time division terminals may use only an uplink subframe among frequency bands used in the communication between the terminal and the base station, or downlink subframes. Only frames may be used, or both uplink and downlink subframes may be used.

In addition, direct communication between time division terminals may use a frequency band different from that used in the communication between the terminal and the base station.

When the communication between the terminal and the base station is a frequency division scheme, the direct communication between the frequency division terminals may use both an uplink frequency band and a downlink frequency band used in the communication between the terminal and the base station, or may be used in the communication between the terminal and the base station. It is possible to use a frequency band different from the frequency band.

Unless otherwise specified below, direct communication between terminals is assumed and described as a link from a first terminal to a second terminal. That is, the first terminal refers to a terminal for transmitting data, and the second terminal refers to a terminal for receiving data.

3 is a flowchart illustrating a direct communication method between terminals according to an embodiment of the present invention.

Referring to FIG. 3, the first terminal 11 and the second terminal 21 perform direct communication between the terminals, the first terminal 11 is located within the cell range of the first base station 10, and the second terminal. 21 is located within the cell range of the second base station 20.

In direct communication between terminals, the base station transmits resource allocation information, modulation and coding scheme (MCS) information, precoding information, and the like to the terminal. In order to perform this adaptive transmission, the base station needs channel state information (CSI) of a direct communication link between terminals. The direct communication link between terminals is called D2D, and the channel state information of the D2D is called D2D-CSI.

The first terminal 11 must transmit a reference signal (RS) to the second terminal 21 so that the second terminal 21 can measure the D2D-CSI. A reference signal for measuring D2D-CSI is called a channel state information-sounding reference signal (CSI-SRS).

The first base station 10 transmits the CSI-SRS configuration information related to the CSI-SRS transmission through higher layer signaling to enable the first terminal 11 to transmit the CSI-SRS. It can be transmitted to (S100). Here, the higher layer signaling may mean radio resource control (RRC) signaling in 3GPP. The CSI-SRS configuration information may include resource allocation information, MCS information, precoding information, and the like for CSI-SRS transmission.

The second base station 20 may transmit the CSI-SRS configuration information related to the CSI-SRS reception to the second terminal 21 through higher layer signaling so that the second terminal 21 may receive the CSI-SRS. Configuration information related to the D2D-CSI report may be transmitted to the second terminal 21 through higher layer signaling (S110). The CSI-SRS configuration information may include resource allocation information, MCS information, precoding information, etc. for receiving the CSI-SRS, and configuration information related to D2D-CSI reporting may include resource allocation information and MCS information for D2D-CSI transmission. , Precoding information, and the like.

Here, step S110 is described as being performed after step S100, but the order in which step S110 is performed is not limited thereto, and step S110 may be performed before step S100 or may be performed simultaneously with step S100.

In operation S120, the first terminal 11 may transmit the CSI-SRS to the second terminal 21 based on the CSI-SRS transmission configuration information, and the second terminal 21 may be based on the CSI-SRS reception configuration information. CSI-SRS may be received.

The second terminal 21 may generate a D2D-CSI based on the received CSI-SRS (S130), and transmit the generated D2D-CSI to the second base station 20 based on the D2D-CSI report configuration information. It may be (S140).

Meanwhile, according to an embodiment, the transmission structure of the CSI-SRS may be the same as the SRS (hereinafter, referred to as '3GPP-SRS') in 3GPP. However, configuration information of the CSI-SRS and the 3GPP-SRS may be different. 3GPP-SRS configuration information may be divided into cell-specific SRS configuration information and UE-specific SRS configuration information. Similarly, the CSI-SRS configuration information may also be divided into SRS configuration information for each cell and SRS configuration information for each terminal.

The CSI-SRS configuration information transmitted by the base station to the terminal may basically include CSI-SRS configuration information for each terminal. In addition, the CSI-SRS configuration information may or may not include CSI-SRS configuration information for each cell. If the CSI-SRS configuration information for each cell is not included in the CSI-SRS configuration information, the UE may use cell-specific 3GPP-SRS configuration information of the cell to which it belongs as CSI-SRS configuration information for each cell.

Upon receiving the CSI-SRS, the UE may periodically or aperiodically report the D2D-CSI to the base station. The D2D-CSI report can be divided into several types according to the type of information constituting the D2D-CSI. The first type is a D2D-CSI report including channel quality indicator (CQI) information for one codeword. The second type is a D2D-CSI report that includes rank indicator (RI) information. The third type is a D2D-CSI report that includes precoding matrix indicator information and respective channel quality indicator information for a plurality of codewords.

The base station may determine which MCS to use based on the channel quality indicator information included in the D2D-CSI report, and determine how many layers to use for the D2D link based on the rank indicator information included in the D2D-CSI report. In addition, based on the precoding matrix indicator information included in the D2D-CSI report, it is possible to determine which precoding matrix to use for the D2D link.

The base station may inform the terminal of the D2D-CSI report type through higher layer signaling. For example, the base station may request the terminal to perform the first type of D2D-CSI report, and may request the terminal to perform the second type of D2D-CSI report and the third type of D2D-CSI report together.

In detail, when the transmission rank is 1 in the first type and only one codeword is transmitted, the UE may generate channel quality indicator information for one codeword for the entire band in which the CSI-SRS is transmitted. Can be.

In the second type, the terminal may generate rank indicator information for the entire band in which the CSI-SRS is transmitted. In this case, the terminal may use a plurality of CSI-SRS, the CSI-SRS may be transmitted in different bands.

In the third type, the terminal may assume the rank indicator information calculated through the second type as the transmission rank, and the number of codewords assumed by the terminal may vary according to the transmission rank. For example, if the transmission rank is 1, the terminal may assume that one codeword is transmitted. If the transmission rank is greater than 1, the terminal may assume that a plurality of codewords are transmitted.

The UE may assume the number of codewords and the transmission layer determined based on the transmission rank, and simultaneously calculate precoding matrix indicator information and channel quality indicator information for the entire band in which the CSI-SRS is transmitted. In this case, when the transmission rank is 1, the terminal may calculate channel quality indicator information for one codeword, and when the transmission rank is greater than 1, the terminal may calculate channel quality indicator information for a plurality of codewords. . If there is only one precoding matrix corresponding to a transport layer determined according to a transmission rank in a precoding codebook, the UE may calculate channel quality indicator information assuming the one precoding matrix, and D2D-CSI. You can exclude the precoding matrix indicator information from the report.

The terminal may transmit the D2D-CSI generated based on the above scheme to the base station, and the physical channel for transmitting the D2D-CSI report may be the same as the physical channel for transmitting channel state information on downlink between the base station and the terminal. have. However, the transmission period and offset of the physical channel for transmitting the D2D-CSI report may be different from the transmission period and offset of the physical channel for transmitting the channel state information on the downlink between the base station and the terminal. In addition, the physical resource of the physical channel for transmitting the D2D-CSI report may be different from the physical resource of the physical channel for transmitting the channel state information for the downlink between the base station and the terminal.

In direct communication between terminals, a physical channel may include a physical data channel (ie, a physical shared channel) and a physical control channel. The physical data channel used in the direct communication between terminals may be defined as a D2D-physical shared channel (D2D-PSCH), and the physical control channel may be defined as a D2D-physical control channel (D2D-PCCH). D2D data may be transmitted through the D2D-PSCH, and hybrid automatic repeat request-acknowledgment (HARQ-ACK) for the D2D-PSCH may be transmitted through the D2D-PCCH. Here, the HARQ-ACK may indicate whether reception of the D2D-PSCH is successful. That is, when the first terminal transmits the D2D-PSCH to the second terminal, the second terminal may transmit the D2D-PCCH to the first terminal in response to the D2D-PSCH.

Next, power control in direct communication between terminals will be described. The UE receiving the D2D-PSCH or the D2D-PCCH may acquire the received power of the D2D-PSCH or the D2D-PCCH, and transmit power control command to the UE that has transmitted the D2D-PSCH or the D2D-PCCH based on the received power. Power can be controlled by transmitting control command (TPC) information. Transmit power control command information for the D2D-PSCH is defined as TPC-D2D-PSCH, and transmit power control command information for the D2D-PCCH is defined as TPC-D2D-PCCH.

For example, when the first terminal transmits the D2D-PSCH to the second terminal, the second terminal may transmit the D2D-PCCH to the first terminal as a response to the D2D-PSCH. In this case, the second terminal may transmit the D2D-PCCH including the TPC-D2D-PSCH for the received D2D-PSCH to the first terminal. The first terminal receiving the D2D-PCCH may transmit a D2D-PSCH including the TPC-D2D-PSCH for the D2D-PCCH to the second terminal.

Next, the structure of the D2D-PSCH will be described. The D2D-PSCH may include new data indicator (NDI) information and D2D control information (D2D-CI). The new data indicator information is an indicator for distinguishing whether at least one codeword transmitted to another terminal is initial transmission or retransmission. According to the scheduling scheme of the D2D-PSCH, new data indicator information or D2D control information may not be transmitted. When the D2D control information is transmitted through the D2D-PSCH, the D2D control information may be configured by a combination of reception success information (ie, HARQ-ACK), TPC-D2D-PSCH, TPC-D2D-PCCH, and the like. Information constituting the D2D control information may vary according to the following situations.

Referring to a case where a D2D-PSCH is transmitted on a link from a first terminal to a second terminal, the first terminal transmits a D2D-PSCH to the second terminal, and the second terminal responds to the received D2D-PSCH. Send the PCCH to the first terminal. In this case, the first terminal may transmit the D2D control information through the D2D-PSCH, and the D2D control information may include the TPC-D2D-PCCH. The second terminal may transmit the TPC-D2D-PSCH to the first terminal through the D2D-PCCH.

Referring to the case where the D2D-PSCH is transmitted in both the link from the first terminal to the second terminal and the link from the second terminal to the first terminal, the first terminal and the second terminal respectively identify D2D-PSCH and D2D-PCCH. Can transmit at the same time. The first base station determines whether to allow simultaneous transmission of D2D-PSCH and D2D-PCCH for each of the first terminal and the second terminal, and performs upper layer signaling to the first terminal (the first terminal is located within a cell range of the first base station). You can tell me. The second base station determines whether to allow simultaneous transmission of the D2D-PSCH and the D2D-PCCH for each of the first terminal and the second terminal, and provides higher layer signaling to the second terminal (the second terminal is located within a cell range of the second base station). You can tell me.

When simultaneous transmission of the D2D-PSCH and the D2D-PCCH is allowed, the UE may simultaneously transmit the D2D-PSCH and the D2D-PCCH. On the other hand, if the D2D-PSCH and the D2D-PCCH should be transmitted at the same time, but simultaneous transmission of the D2D-PSCH and the D2D-PCCH is not allowed, the UE can transmit only the D2D-PSCH including the D2D control information without transmitting the D2D-PCCH. have. In this case, the D2D control information includes information to be transmitted through the D2D-PCCH.

The configuration of the D2D control information may vary depending on whether the simultaneous transmission of the D2D-PSCH and the D2D-PCCH for the first terminal and the simultaneous transmission of the D2D-PSCH and the D2D-PCCH for the second terminal are allowed.

In the following, it is assumed that each of the first terminal and the second terminal should simultaneously transmit the D2D-PSCH and the D2D-PCCH. First, when simultaneous transmission of the D2D-PSCH and the D2D-PCCH for the first terminal is not allowed, the first terminal may generate D2D control information including information to be transmitted through the D2D-PCCH, and the generated D2D control information. It may transmit a D2D-PSCH including.

If simultaneous transmission of the D2D-PSCH and the D2D-PCCH for the second terminal is not allowed, the second terminal may transmit only the D2D-PSCH. Accordingly, when generating the D2D control information, the first terminal may generate the D2D control information including the HARQ-ACK and the TPC-D2D-PSCH. On the other hand, when simultaneous transmission of the D2D-PSCH and the D2D-PCCH for the second terminal is allowed, the second terminal may simultaneously transmit the D2D-PSCH and the D2D-PCCH. Therefore, when generating D2D control information, the first terminal may generate D2D control information including HARQ-ACK, TPC-D2D-PSCH, and TPC-D2D-PCCH.

Next, when simultaneous transmission of the D2D-PSCH and the D2D-PCCH for the first terminal is allowed, the first terminal may simultaneously transmit the D2D-PSCH and the D2D-PCCH. In this case, if simultaneous transmission of the D2D-PSCH and the D2D-PCCH for the second terminal is not allowed, the second terminal may transmit only the D2D-PSCH to the first terminal. Therefore, the first terminal does not transmit the D2D control information. On the other hand, when simultaneous transmission of the D2D-PSCH and the D2D-PCCH for the second terminal is allowed, the second terminal may simultaneously transmit the D2D-PSCH and the D2D-PCCH. Therefore, the first terminal can transmit the D2D control information including the TPC-D2D-PSCH.

4 is a flowchart illustrating a direct communication method between terminals according to another embodiment of the present invention.

Referring to FIG. 4, a first terminal and a second terminal perform direct communication between terminals, and the first terminal may transmit a D2D-PSCH (ie, a physical shared channel) to the second terminal, and the second terminal may receive the second terminal. The D2D-PCCH (ie, a physical control channel) may be transmitted to the first terminal in response to the received D2D-PSCH. Here, the first terminal and the second terminal may belong to the same base station, or may belong to different base stations.

The first terminal may generate data indicator (ie, NDI) information indicating whether the at least one codeword transmitted to the second terminal is super-transmitted (S200). That is, the data indicator information may indicate whether at least one codeword transmitted to the second terminal is supertransmission or retransmission.

The first terminal can transmit a physical shared channel including data indicator information and D2D data to the second terminal (S210). The physical shared channel may further include D2D control information (ie, D2D-CI), and the D2D control information may include power control command information (ie, TPC-D2D-PCCH) for the physical control channel transmitted by the second terminal. It may include. Therefore, the second terminal receiving the physical shared channel may set the transmit power of the physical control channel based on the power control command information for the physical control channel included in the D2D control information.

The first terminal may receive a physical control channel, which is a response to the physical shared channel, from the second terminal (S220). The physical control channel may include power control command information (ie, TPC-D2D-PSCH) for a physical shared channel transmitted by the first terminal. Therefore, when transmitting the physical shared channel later, the first terminal may set the transmit power of the physical shared channel based on the power control command information.

Here, the data indicator information may be allocated to both symbols adjacent to the symbol where the demodulation reference signal is located in the physical shared channel, and the D2D control information may be allocated to the symbol adjacent to the symbol where the data indicator information is located. Hereinafter, a configuration of a D2D-PSCH including data indicator information and D2D control information will be described with reference to FIGS. 5 to 7.

5 is a conceptual diagram illustrating an embodiment of the configuration of the D2D-PSCH, FIG. 6 is a conceptual diagram illustrating another embodiment of the configuration of the D2D-PSCH, and FIG. 7 is another conceptual diagram of the configuration of the D2D-PSCH. It is a conceptual diagram which shows an Example.

5 to 7, the D2D-PSCH may include a plurality of symbols in the time domain and a plurality of physical resource blocks (PRBs) in the frequency domain. The subframe of the D2D-PSCH may include a first slot and a second slot, and the frequency position where each slot is transmitted may be different. Each slot may include seven symbols, and the first symbol in the first slot and the last symbol in the second slot (ie, the seventh symbol) may not be used for transmission. In the center of each slot, a demodulation reference signal (DM-RS) used for demodulation of the D2D-PSCH may be located.

Both data indicator (NDI) information and D2D control information (D2D-CI) may be transmitted through the D2D-PSCH, or only one of the two may be transmitted, or both may not be transmitted.

When the data indicator information or the D2D control information is transmitted, as shown in FIG. 5, the data indicator information or the D2D control information may be allocated to both of the symbols adjacent to the demodulation reference signal. For example, when the demodulation reference signal is located in the fourth symbol in the slot, the data indicator information or the D2D control information may be located in the third symbol and the fifth symbol.

When both the data indicator information and the D2D control information are transmitted, data indicator information may be allocated to both the symbol where the demodulation reference signal is located and the symbol adjacent to each other, as shown in FIGS. 6 and 7, and the symbol that is adjacent to the symbol where the data indicator information is located. D2D control information may be allocated to the.

For example, if the first symbol of the first slot and the last symbol of the second slot are not used for transmission, if the demodulation reference signal is located in the fourth symbol within the first slot and the second slot, the data indicator information is set to three. The second and fifth symbols may be located, and the D2D control information may be located in the second and sixth symbols.

On the other hand, if the first symbol of the first slot and the sixth and seventh symbols of the second slot are not used for transmission, if the demodulation reference signal is located in the fourth symbol within the first slot, the data indicator information is the third symbol. And the fifth symbol, and the D2D control information may be located in the second symbol and the sixth symbol. If the demodulation reference signal is located in the fourth symbol in the second slot, the data indicator information may be located in the third and fifth symbols, and the D2D control information may be located in the second symbol.

8 is a flowchart illustrating a direct communication method between terminals according to another embodiment of the present invention.

Referring to FIG. 8, the first terminal and the second terminal perform direct communication between the terminals, and the first terminal and the second terminal may belong to the same base station or may belong to different base stations.

When simultaneous transmission of a physical shared channel (ie, D2D-PSCH) and a physical control channel (ie, D2D-PCCH) for the first terminal is not allowed, the first terminal is transmitted to the second terminal through a physical control channel. D2D control information (ie, D2D-CI) including the control information may be generated (S300).

In this case, when simultaneous transmission of the physical control channel and the physical shared channel for the second terminal is not allowed, the first terminal responds to data reception (ie, HARQ-ACK) and power control command information for the physical shared channel. (Ie, TPC-D2D-PSCH) can be generated. On the other hand, when simultaneous transmission of the physical control channel and the physical shared channel for the second terminal is allowed, the first terminal responds to data reception, power control command information for the physical shared channel, and power control for the physical control channel. D2D control information including command information (ie, TPC-D2D-PCCH) may be generated.

The first terminal may transmit a physical shared channel including the D2D control information and the D2D data to the second terminal (S310). Here, the physical shared channel may further include data indicator information (ie, NDI) indicating whether the at least one codeword transmitted to the second terminal is super-transmitted. The data indicator information may indicate whether at least one codeword transmitted to the second terminal is supertransmission or retransmission.

The first terminal may receive a response of the physical shared channel from the second terminal (S320). When simultaneous transmission of the physical shared channel and the physical control channel to the second terminal is allowed, the first terminal may receive the physical shared channel and the physical control channel from the second terminal. On the other hand, when simultaneous transmission of the physical shared channel and the physical control channel to the second terminal is not allowed, the first terminal may receive the physical shared channel from the second terminal.

Here, the data indicator information may be allocated to both symbols adjacent to the symbol where the demodulation reference signal is located in the slot, and the D2D control information may be allocated to the symbol adjacent to the symbol where the data indicator information is located. That is, the data indicator information and the D2D control information may be allocated to the positions shown in FIGS. 5 to 7.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

10: First base station
11:
20: second base station
21:
30: Central China

Claims (20)

A communication method of the second terminal for direct communication between a first terminal and a second terminal,
Receiving first configuration information for receiving a reference signal and second configuration information for reporting channel state information from the base station;
Receiving a reference signal from the first terminal based on the first configuration information;
Generating channel state information on a communication link between the first terminal and the second terminal based on the reference signal; And
And transmitting the channel state information to the base station based on the second configuration information. The method according to claim 1,
Generating the channel state information,
And generating channel state information including channel quality indication information. The method according to claim 2,
Generating the channel state information,
When the transmission rank is 1 and one codeword is transmitted, second channel quality indicator information for the one codeword is generated for the entire band in which the reference signal is transmitted. Communication method of the terminal. The method according to claim 1,
Generating the channel state information,
And generating channel state information including rank indication information. The method of claim 4,
Generating the channel state information,
And generating rank indicator information for the entire band on which the reference signal is transmitted based on at least one reference signal. The method according to claim 1,
Generating the channel state information,
And generating channel state information including precoder matrix indication information and channel quality indicator information. The method of claim 6,
Generating the channel state information,
And generating precoder matrix indicator information and channel quality indicator information based on the number of codewords and the transmission layer determined according to the transmission rank. The method according to claim 1,
The step of transmitting the channel state information to the base station,
And providing channel state information on a communication link between the first terminal and the second terminal to the base station by using a physical channel for transmitting downlink channel state information between the base station and the second terminal. The communication method of the second terminal. The method of claim 8,
The step of transmitting the channel state information to the base station,
And a transmission period and an offset different from a physical channel for transmitting channel state information on downlink between the base station and the second terminal. A communication method of the first terminal for direct communication between a first terminal and a second terminal,
Generating data indicator information indicating whether initial transmission of at least one codeword transmitted to the second terminal is performed;
Transmitting a physical shared channel including the data indicator information and device to device (D2D) data to the second terminal; And
Receiving from the second terminal a physical control channel which is a response of the physical shared channel. The method of claim 10,
The physical shared channel is,
The method of claim 1, further comprising D2D control information having power control command information for the physical control channel. The method of claim 10,
The physical control channel,
And a power control command information for a physical shared channel. The method of claim 10,
The data indicator information,
And a symbol in which a demodulation reference signal is located in the physical shared channel, and a neighboring symbol. The method of claim 11,
The data indicator information is allocated to both symbols adjacent to the symbol where the demodulation reference signal is located in the physical shared channel, and the D2D control information is allocated to a symbol adjacent to the symbol where the data indicator information is located. 1 terminal communication method. A communication method of the first terminal for direct communication between a first terminal and a second terminal,
Generating device to device (D2D) control information including control information transmitted to the second terminal through a physical control channel; And
And transmitting a physical shared channel including the D2D control information and the D2D data to the second terminal. 16. The method of claim 15,
Generating the D2D control information,
When simultaneous transmission of a physical control channel and a physical shared channel for the second terminal is not allowed, the D2D control information including response information for receiving data and power control command information for the physical shared channel is generated. Communication method of the first terminal. 16. The method of claim 15,
Generating the D2D control information,
When simultaneous transmission of the physical control channel and the physical sharing channel to the second terminal is allowed, the response information including response information for data reception, power control command information for the physical sharing channel, and power control command information for the physical control channel are included. And generating D2D control information. 16. The method of claim 15,
The physical shared channel is,
And a data indicator information indicating whether or not initial transmission of at least one codeword transmitted to the second terminal. 19. The method of claim 18,
The data indicator information,
And a symbol in which a demodulation reference signal is located in the physical shared channel, and a neighboring symbol. 19. The method of claim 18,
The data indicator information is allocated to both symbols adjacent to the symbol where the demodulation reference signal is located in the physical shared channel, and the D2D control information is allocated to a symbol adjacent to the symbol where the data indicator information is located. 1 terminal communication method.

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