KR20150128477A - Method and apparatus of power control for d2d communication - Google Patents

Abstract

The present invention relates to a method which supports a power control for device-to-device (D2D) communications. The method comprises the following steps: receiving an RRC message including a TPC-RNTI parameter and a TPC index parameter from a base station (eNB); receiving a PDCCH having DCI format 3/3A including a TPC command from the eNB; detecting the PDCCH based on a certain RNTI included in the TPC-RNTI parameter; and detecting the TPC command for the D2D communications from the DCI format 3/3A based on at least one between the TPC-RNTI parameter and the TPC index parameter. According to the present invention, the method can efficiently perform the power control, and mitigate an interference which occurs on a cellular network by the D2D communications.

Description

TECHNICAL FIELD [0001] The present invention relates to a power control method for a D2D communication,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communication, and more particularly, to a power control method and apparatus for device to device (D2D) communication.

Transmission power control (TPC) is a technique for solving the perspective problem that occurs when the UEs are distributed close to or far from the base station and transmit signals. Assuming that all terminals transmit signals with the same power, the signal transmitted by the terminal located close to the base station is much larger than the signal transmitted by the terminal located far away. Therefore, a nearby terminal has no problem in talking, but a far-away terminal experiences a relatively large interference. Therefore, the TPC is a technique for adjusting the transmission power of each terminal and receiving the signal with uniform power intensity. For the transmission power control, the base station can transmit a TPC command (commnand) to the terminal. The TPC command may be applied to a specific subframe.

On the other hand, device to device communication (D2D communication) is a communication method that has been available since the time of an analog radio, and has a very long history. However, the inter-terminal communication in the wireless communication system is different from the existing inter-terminal communication.

The direct communication between the terminals in the wireless communication system is performed by using the transmission / reception technology (for example, physical channel, etc.) of the wireless communication system in the frequency band of the wireless communication system or other bands, And communication of user data directly between terminals. That is, the two terminals perform communication while being a source and a destination of data, respectively. This provides the advantage of enabling wireless communication in areas other than the limited wireless communication infrastructure and reducing the network load of the wireless communication system.

Direct communication between terminals may be performed using a communication method using a wireless LAN such as IEEE 802.11 or a license-exempt band such as Bluetooth, but it is difficult to provide a planned and controlled service using the communication method using the license-exempt band. In particular, performance can be drastically reduced by interference. On the other hand, the direct communication between the terminals operated or provided in the licensed band or inter-system interference controlled environment can support QoS (Quality of Service), increase frequency utilization efficiency through frequency reuse, The possible distance can be increased.

In this case, resources for direct communication between terminals in the license band, i.e., direct communication between terminals based on cellular communication, may be predefined or allocated through a base station, and a cellular uplink channel or an uplink service Frames may be used. That is, the direct communication between the UEs based on the cellular communication can transmit a signal from the Tx UE to the Rx UE through the cellular uplink. In this case, the signal is transmitted to a cellular network (for example, a WAN Interference may occur. Power control for D2D communication is required to minimize the influence of the above-mentioned interference to the cellular network and to support the D2D communication properly.

SUMMARY OF THE INVENTION The present invention provides a power control method and apparatus for D2D communication.

Another aspect of the present invention is to provide a D2D power control signaling method and apparatus considering a DCI (Downlink Control Information) format.

A further technical object of the present invention is to provide a D2D power control signaling method and apparatus based on DCI format 3 / 3A.

A further technical object of the present invention is to provide a TPC index for power control of D2D communication.

Another aspect of the present invention is to provide an RNTI for power control of D2D communication.

According to an aspect of the present invention, there is provided a power control method for D2D (Device to Device) communication performed by a base station (evolved-NodeB, eNB). The method includes generating a Radio Resource Control (RRC) message including a TPC (Transmission Power Control) -RNTI (Radio Network Temporary Identifier) parameter and a TPC index parameter, transmitting the generated RRC message to a Tx (UE), generating a Physical Downlink Control Channel (PDCCH) having a Downlink Control Information (DCI) Format 3 or 3A including a TPC command, and transmitting the generated PDCCH to the Tx terminal , Wherein at least one of the TPC-RNTI parameter and the TPC index parameter indicates that the TPC command included in the DCI format 3 or 3A is a TPC command for D2D communication.

According to another aspect of the present invention, there is provided a method for supporting D2D (Device to Device) communication performed by a transmission (Tx) terminal UE. The method includes receiving an RRC (Radio Resource Control) message including a TPC (Radio Network Temporary Identifier) parameter and a TPC index parameter from a base station (eNB) Comprising the steps of: receiving from a Node B a Physical Downlink Control Channel (PDCCH) having a Downlink Control Information (DCI) format 3 or 3 A; detecting the PDCCH based on a specific RNTI included in the TPC-RNTI parameter; Detecting a TPC command for D2D communication from the DCI format 3 or 3A based on at least one of the RNTI parameter and the TPC index parameter.

According to another aspect of the present invention, there is provided an evolved-NodeB (eNB) supporting power control for D2D (Device to Device) communication. The base station generates an RRC (Radio Resource Control) message including a TPC (Transmission Power Control) -RNTI (Radio Network Temporary Identifier) parameter and a TPC index parameter, and transmits a Downlink Control Information (DCI) A processor for generating a Physical Downlink Control Channel (PDCCH) having a format 3 or 3A and an RF unit for transmitting the generated RRC message and PDCCH to a transmission (Tx) user equipment (UE), wherein the TPC- Parameter and the TPC index parameter indicates that the TPC command included in the DCI format 3 or 3A is a TPC command for D2D communication.

According to another aspect of the present invention, there is provided a transmission (Tx) terminal (UE) supporting power control for D2D (Device to Device) communication. The Tx terminal receives an RRC (Radio Resource Control) message including a TPC (Transmission Power Control) -RNTI (Radio Network Temporary Identifier) parameter and a TPC index parameter from a base station (eNB) An RF unit for receiving a Physical Downlink Control Channel (PDCCH) having a Downlink Control Information (DCI) format 3 or 3A from the base station, and a PDCCH based on a specific RNTI included in the TPC-RNTI parameter, And a processor for detecting a TPC command for D2D communication from the DCI format 3 or 3A based on at least one of the RNTI parameter and the TPC index parameter.

According to the present invention, in performing D2D communication, power control can be efficiently performed, and interference generated in a cellular network can be mitigated by D2D communication.

1 shows a wireless communication system to which the present invention is applied.
2 and 3 schematically show the structure of a radio frame applied to the present invention.
4 is a diagram for explaining the concept of a cellular network-based D2D communication applied to the present invention.
5 is a flow chart illustrating a method for supporting power control for D2D communication in accordance with the present invention.
6 is a block diagram illustrating a wireless communication system supporting D2D communication according to the present invention.

Hereinafter, some embodiments will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals even though they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present disclosure rather unclear.

1 shows a wireless communication system to which the present invention is applied.

Referring to FIG. 1, a wireless communication system 10 is widely deployed to provide various communication services such as voice, packet data, and the like. The wireless communication system 10 includes at least one base station 11 (evolved-NodeB, eNB). Each base station 11 provides communication services to specific cells (15a, 15b, 15c). The cell may again be divided into multiple regions (referred to as sectors).

A user equipment (UE) 12 may be fixed or mobile and may be a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, (personal digital assistant), a wireless modem, a handheld device, and the like. The base station 11 may be referred to by other terms such as a base station (BS), a base transceiver system (BTS), an access point, a femto base station, a home node B, and a relay. Cells are meant to cover various coverage areas such as megacell, macrocell, microcell, picocell, and femtocell.

Hereinafter, downlink (DL) refers to communication from the base station 11 to the terminal 12, and uplink (UL) refers to communication from the terminal 12 to the base station 11. In the downlink, the transmitter may be part of the base station 11, and the receiver may be part of the terminal 12. In the uplink, the transmitter may be part of the terminal 12, and the receiver may be part of the base station 11. There are no restrictions on multiple access schemes applied to wireless communication systems. (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA , OFDM-CDMA, and the like. A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

The layers of the radio interface protocol between the terminal and the base station are divided into a first layer (L1), a second layer (L1), and a second layer (L2) based on the lower three layers of an Open System Interconnection A second layer (L2), and a third layer (L3). Among them, the physical layer belonging to the first layer provides an information transfer service using a physical channel.

The physical layer is connected to a MAC layer (Media Access Control) layer through a transport channel. The data is transmitted between the MAC layer and the physical layer through a transmission channel. The transport channel is classified according to how the data is transmitted over the air interface. Further, data is transmitted through physical channels between different physical layers (i.e., between the physical layer of the terminal and the base station). The physical channel can be modulated by an Orthogonal Frequency Division Multiplexing (OFDM) scheme, and uses time, frequency, and space generated by a plurality of antennas as radio resources.

2 and 3 schematically show the structure of a radio frame applied to the present invention.

Referring to FIG. 2 and FIG. 3, one radio frame includes ten subframes, and one subframe includes two consecutive slots. A basic time (length) unit for transmission control in a radio frame is referred to as a transmission time interval (TTI). The TTI may be 1ms. The length of one subframe (1 subframe) is 1 ms, and the length of one slot may be 0.5 ms.

A slot may comprise a plurality of symbols in the time domain. For example, in a wireless system using OFDMA in a downlink (DL), the symbol may be an Orthogonal Frequency Division Multiplexing (OFDM) symbol, and in an uplink (UL) In the case of a wireless system using Single Carrier-Frequency Division Multiple Access (FDMA), the symbol may be a Single Carrier-Frequency Division Multiple Access (SC-FDMA) symbol. On the other hand, the representation of the symbol period in the time domain is not limited by the multiple access scheme or name.

The number of symbols included in one slot may vary according to the length of a CP (Cyclic Prefix). For example, in the case of a normal CP, one slot includes seven symbols, and in the case of an extended CP, one slot may include six symbols.

A resource element (RE) represents a smallest time-frequency unit to which a modulation symbol of a data channel or a modulation symbol of a control channel is mapped. A resource block (RB) is a resource allocation unit and includes time-frequency resources corresponding to 180 kHz on the frequency axis and 1 slot on the time axis. On the other hand, a resource block pair (PBR) means a resource unit including two consecutive slots on the time axis.

Several physical channels can be used in the physical layer, and the physical channels can be mapped to the radio frame and transmitted. As a downlink physical channel, a physical downlink control channel (PDCCH) / enhanced physical downlink control channel (EPDCCH) includes a resource allocation of a paging channel (PCH) and a downlink shared channel (DL-SCH) Request information. The PDCCH / EPDCCH may carry an uplink grant informing the UE of the resource allocation of the uplink transmission. PDCCH and EPDCCH are different in the resource area to be mapped. A DL-SCH is mapped to a PDSCH (Physical Downlink Shared Channel). The Physical Control Format Indicator Channel (PCFICH) informs the UE of the number of OFDM symbols used in the PDCCH and is transmitted every subframe. The Physical Hybrid ARQ Indicator Channel (PHICH) is a downlink channel that carries an HARQ (Hybrid Automatic Repeat reQuest) ACK (Acknowledgment) / NACK (Non-acknowledgment) signal, which is a response of an uplink transmission. The HARQ ACK / NACK signal may be referred to as an HARQ-ACK signal.

As an uplink physical channel, Physical Random Access Channel (PRACH) carries a random access preamble. The Physical Uplink Control Channel (PUCCH) includes HARQ-ACK, which is a response of downlink transmission, channel status information (CSI) indicating a downlink channel status, for example, a channel quality indicator (CQI) Uplink control information such as a precoding type indicator (PTI), a rank indicator (RI), and the like. The Physical Uplink Shared Channel (PUSCH) carries an Uplink Shared Channel (UL-SCH).

A plurality of PDCCH / EPDCCHs may be transmitted within the control domain, and the UE may monitor a plurality of PDCCH / EPDCCHs. The PDCCH / EPDCCH is transmitted on an aggregation of one or several consecutive control channel elements (CCEs). The CCE is a logical allocation unit used to provide the coding rate according to the state of the radio channel to the PDCCH / EPDCCH. The CCE corresponds to a plurality of resource element groups. The format of the PDCCH / EPDCCH and the number of possible PDCCH / EPDCCH bits are determined according to the relationship between the number of CCEs and the coding rate provided by the CCEs.

The control information transmitted through the PDCCH / EPDCCH is referred to as downlink control information (DCI). Table 1 below shows the DCI according to various formats.

A plurality of PDCCH / EPDCCHs may be transmitted within the control domain, and the UE may monitor a plurality of PDCCH / EPDCCHs. The PDCCH / EPDCCH is transmitted on an aggregation of one or several consecutive control channel elements (CCEs). The CCE is a logical allocation unit used to provide the coding rate according to the state of the radio channel to the PDCCH / EPDCCH. The CCE corresponds to a plurality of resource element groups. The format of the PDCCH / EPDCCH and the number of possible PDCCH / EPDCCH bits are determined according to the relationship between the number of CCEs and the coding rate provided by the CCEs.

The control information transmitted through the PDCCH / EPDCCH is referred to as downlink control information (DCI). Table 1 below shows the DCI according to various formats.

DCI format Explanation 0 Used in scheduling of PUSCH (uplink common channel) in uplink cell One Used for scheduling one PDSCH codeword in one cell 1A Used for simple scheduling of one PDSCH codeword in one cell and in a random access procedure initiated by a PDCCH command. 1B Used for simple scheduling of one PDSCH codeword in one cell using precoding information 1C Used for brief scheduling of one PDSCH codeword and notification of MCCH changes 1D Used for simple scheduling of one PDSCH codeword in one cell, including precoding and power offset information. 2 Used for PDSCH scheduling for terminals configured in spatial multiplexing mode. 2A Used for PDSCH scheduling of UEs configured in CDD mode with large delay. 2B Used in transmission mode 8 (dual layer transmission, etc.) 2C Used in transmission mode 9 (multi layer transmission) 2D Used in transfer mode 10 (CoMP) 3 Used for transmission of TPC commands for PUCCH and PUSCH with 2-bit power adjustment 3A Used for transmission of TPC commands for PUCCH and PUSCH with single bit power adjustment. 4 Used for scheduling of PUSCH in multi-antenna port transmission mode cell for uplink

Referring to Table 1, the DCI format includes a format 0 for PUSCH scheduling in a UL cell, a format 1 for scheduling one PDSCH codeword, a format 1A for compact scheduling of one PDSCH codeword, a DL- SCH for very simple scheduling, Format 2 for PDSCH scheduling in a closed-loop spatial multiplexing mode, Format 2A for PDSCH scheduling in an open-loop spatial multiplexing mode, A format 2B used in a transmission mode (TM) 8, a format 2C used in a transmission mode 9, a format 2D used in a transmission mode 10, a format for transmission of a transmission power control (TPC) command for an uplink channel 3 and 3A, and a format 4 for PUSCH scheduling in a multi-antenna port transmission mode for an uplink.

Each field of the DCI is sequentially mapped to _n information bits a ₀ through a _{n -1} . For example, if the DCI is mapped to a total of 44 bits of information bits, each DCI field is sequentially mapped to a ₀ to a ₄₃ . DCI formats 0, 1A, 3, and 3A may all have the same payload size. The DCI formats 0 and 4 may be referred to as UL grants (uplink grants).

Meanwhile, user data may be transmitted on the PUSCH, and the user data may be a transport block (TB), which is a data block for a UL-SCH transmitted during a TTI (Transmission Time Interval).

The setting of the transmission power of the terminal for PUSCH transmission can be defined as follows.

If the UE transmits a PUSCH not simultaneously with the PUCCH for the serving cell c (PUSCH without a simultaneous PUCCH for the serving cell c), then the PUSCH is transmitted in the subframe i for the serving cell c P _{PUSCH , c} (i), which is the terminal transmission power for the mobile station, is given by Equation 1 below.

If the UE transmits a PUSCH for the serving cell c simultaneously with the PUCCH, then P _{PUSCH, c} (i) _, which is the UE transmission power for the PUSCH transmission in the subframe i for the serving cell c, Given.

If the UE is not transmitting a PUSCH for accumulation of TPC commands received with DCI format 3 / 3A for PUSCH for serving cell c (if the UE is not transmitting PUSCH for the serving cell c, for the accumulation of TPC command received with DCI format 3 / 3A for PUSCH), P _{PUSCH , c} (i) _, which is the terminal transmission power for PUSCH transmission in subframe i for the serving cell c, the terminal assumes that it is computed by the terminal.

는 P_{CMAX ,c}(i)의 선형 값이다.Where P _{CMAX , c} (i) is the maximum UE transmit power configured for serving cell c,

Is the linear value of P _{CMAX , c} (i).

는 P_PUCCH(i)의 선형 값이다. P_PUCCH(i)는 서브프레임 i에서의 PUCCH 전송 전력이다.

Is the linear value of P _PUCCH (i). P _PUCCH (i) is the PUCCH transmit power in subframe i.

Also, M _{PUSCH , c} (i) is a value expressed by the number of RBs in the bandwidth of the resource to which the PUSCH is allocated in the subframe i for the serving cell c.

In _{addition, P O _ PUSCH, c (} j) is the sum of the P _{O _ NOMINAL _ PUSCH, c} (j) and P _{O _ UE _ PUSCH, c} (j) for the serving cell c, the value j from the upper layer 0 or 1. J is 0 for semi-persistent grant PUSCH transmission (or retransmission) whereas j is 1 for dynamic scheduled grant PUSCH transmission (or retransmission), while random access response grant PUSCH transmission (Or retransmission), j is 2. In the case where the random access response grant PUSCH transmission (or retransmission) P _{O _ UE _} and _{PUSCH, c (2) = 0} , P O_NOMINAL_PUSCH, c (2) is the sum of the P _{O _ PRE} and Δ _{PREAMBLE _ Msg3,} here, the parameter P _{O_PRE} (preambleInitialReceivedTargetPower) and Δ _{PREAMBLE _ Msg3} is signaled from higher layers.

If j is 0 or 1, one of the values α _c ∈ {0, 0, 4, 0.5, 0.6, 0.7, 0.8, 0.9, 1} may be selected by the 3-bit parameter provided in the upper layer. When j is 2, α _c (j) = 1 at all times.

PL _c is the dB value of the downlink path loss (PL, or path attenuation) estimate for the serving cell c at the terminal, and can be obtained from "referenceSignalPower - higher layer filtered RSRP". Here, referenceSignalPower is a value provided in the upper layer, and is a unit of dBm of the EPRE (Energy Per Resource Element) value of the DL reference signal. Reference Signal Received Power (RSRP) is the received power value of the reference signal for the reference serving cell. The decision of the serving cell selected as the reference serving cell and the referenceSignalPower and the higher layer filtered RSRP used for the calculation of the PL _c is made by the upper layer parameter pathlossReferenceLinking. Here, the reference serving cell formed by the pathlossReferenceLinking may be the DL serving cell of the serving cell or the serving serving cell connected to the UL CC and the SIB2 connection.

이다. 여기서, K_s는 각 서빙셀 c에 대하여 상위계층에서 deltaMCS-Enabled으로 제공되는 파라미터이며 1.25 또는 0이며, 특히, 전송 다이버시티(Transmit diversity)를 위한 모드인 전송 모드2(transmission mode 2)인 경우 K_s는 언제나 0이다. 또한, UL-SCH 데이터 없이 PUSCH를 통해 제어정보만이 전송되는 경우 BPRE=O_CQI/N_RE이고, 그 밖의 경우

인데, C는 코드블록의 개수이며, K_r은 코드블록의 크기이며, O_CQI는 CRC 비트수를 포함한 CQI/PMI 비트 개수이며, N_RE는 결정된 자원 요소(Resource Element)들의 개수(즉,

)이다. M^{PUSCH-initial} _sc는 동일한 전송 블록에 대한 초기(initial) PUSCH 전송을 위한 부반송파의 수이고, N^{PUSCH - initial} _Symb는 동일한 전송 블록에 대한 초기(initial) PUSCH 전송을 위한 서브프레임당 SC-FDMA 심벌의 수이다. 또한, 만일 PUSCH를 통해 UL-SCH 데이터 없이 제어정보만이 전송되는 경우 β^PUSCH _offset=β^CQI _offset로 설정하고, 그 이외의 경우는 β^PUSCH _offset는 항상 1로 설정한다.Further,? _{TF , c} (i) is a parameter for reflecting an influence by a modulation coding scheme (MCS)

to be. Here, K _s is a parameter provided as deltaMCS-Enabled in the upper layer for each serving cell c and is 1.25 or 0. In particular, in the case of transmission mode 2, which is a mode for transmit diversity K _s is always zero. Also, when only control information is transmitted through the PUSCH without UL-SCH data, BPRE = O _CQI / N _RE , and in other cases

Inde, C is the number of code blocks, K _r is the size of the code block, O _CQI is CQI / PMI bit number including the number of CRC bits, N _RE is the number of the determined resource element (Resource Element) (i.e.,

)to be. M ^{PUSCH-initial} _sc is the number of subcarriers for initial PUSCH transmission for the same transport block, and N ^{PUSCH - initial} _Symb is the number of SC-FDMA symbols per subframe for initial PUSCH transmission for the same transport block. ≪ / RTI > Also, if only the control information is transmitted without UL-SCH data through the PUSCH,? ^PUSCH _offset =? ^CQI _offset is set. Otherwise ^{,? PUSCH} _offset is always set to 1.

In addition, f _c (i) is the PUSCH power control adjustment state (PUSCH power control adjustment state) for the serving cell c.

Also,? _{PUSCH , c} is a correction value and may also be referred to as a "TPC command ". δ _{PUSCH , c} may be included in the PDCCH / EPDCCH with DCI format 0 or 4 (0/4) for the serving cell c or jointly with other TPC commands on the PDCCH with DCI format 3 / 3A coded. In the DCI format 3 / 3A, the CRC parity bits are scrambled with a TPC-PUSCH-RNTI (Radio Network Temporary Identifier) so that only the UEs to which the RNTI value is assigned can be checked.

For example, DCI format 3 / 3A has the following characteristics.

이고, L_format0은, DCI 포맷 0이 공용 검색 공간(common search space)에 맵핑된 때(when), CRC 부가(attachment) 전 DCI 포맷 0의 페이로드 사이즈와 같다. 여기서 상기 페이로드 사이즈는 상기 DCI 포맷 0에 패딩 비트들이 첨부된(apended) 것을 고려한다. 파라미터 TPC 인덱스(tpc-Index)는 상위 계층에 의하여 제공되며, 상기 TPC 인덱스는 단말을 위한 TPC 명령에 대한 인덱스를 결정한다. 만약

인 경우, 0 값의 비트가 DCI 포맷 3에 첨부된다.DCI Format 3 is used for transmission of TPC commands for PUCCH and PUSCH with 2 bit power adjustments.
The following information is transmitted by means of DCI format 3:
- TPC command number 1 (TPC command number 1), TPC command number 2, ..., TPC command number N
here,

And L _format0 is equal to the payload size of DCI format 0 before CRC attachment when DCI format 0 is mapped to the common search space. Where the payload size considers padding bits to be appended to the DCI format 0. The parameter TPC index (tpc-Index) is provided by the upper layer, and the TPC index determines the index for the TPC command for the terminal. if

, A bit of zero value is appended to DCI Format 3.

DCI format 3A is used for transmission of TPC commands for PUCCH and PUSCH with 1 bit power control.
The following information is transmitted by means of DCI format 3A:
- TPC command number 1 (TPC command number 1), TPC command number 2, ..., TPC command number M
Where M = L _format0 and L _{format0 equals} the payload size of DCI format 0 before CRC attachment when DCI format 0 is mapped to the common search space. Where the payload size considers padding bits to be appended to the DCI format 0. The parameter TPC index (tpc-Index) is provided by the upper layer, and the TPC index determines the index for the TPC command for the terminal.

The size of the DCI format 3 / 3A is the same as that of the DCI format 0 (1A) in order to prevent an increase in the number of blind decodings of the UE. That is, DCI format 3 / 3A determines the number of TPC commands that can be transmitted at maximum depending on the payload size of DCI format 0.

 In order to perform TPC command-based power control, an RNTI and a TPC index for the UE are required. The RNTI and the TPC index may be indicated through higher layer signaling, i.e., RRC signaling. For example, the RRC signaling may include the following syntax.

Referring to Table 4, the RRC signaling includes a TPC-PDCCH-Config information element (IE), and the TPC-PDCCH-Config information element includes a tpc-RNTI field and a tpc-Index field. The tpc-RNTI field indicates the RNTI value used for power control based on DCI format 3 / 3A. The RNTI may be a TPC-PUSCH-RNTI or a TPC-PUCCH-RNTI.

The tpc-Index field indicates the above-described TPC index (TPC-Index) parameter, and indicates an index of N or M. Indicating the index of N may mean indicating any one of the indices 1 to N corresponding thereto. Indicating the index of M may mean indicating any one of the indices 1 to M. [ Where N or M depends on the DCI format (3 or 3A) used. Specifically, the TPC index parameter includes indexOfFormat3 information and indexOfFormat3A information. The indexOfFormat3 information indicates an index of a TPC command number when the DCI format 3 is used, and the indexOfFormat3A information indicates an index of a TPC command number when the DCI format 3A is used.

Meanwhile, in recent years, in the frequency band of the wireless communication system or in other bands, D2D communication using direct transmission / reception technology of the wireless communication system but directly exchanging user data between terminals without going through an infrastructure (for example, a base station) A plan is being considered. D2D communication enables wireless communication in an area other than a limited wireless communication infrastructure and reduces the network load of the wireless communication system. In addition, D2D communication provides advantages such as disaster information and the like can be transmitted to terminals even when the base stations do not operate smoothly in a situation of war, disaster or the like.

A terminal transmitting a signal based on D2D communication is referred to as a transmission terminal (Tx UE), and a terminal receiving a signal based on communication between terminals is defined as a reception terminal (Rx UE). The transmitting terminal transmits a discovery signal, and the receiving terminal can receive the discovery signal. The roles of the transmitting terminal and the receiving terminal may be changed. On the other hand, the signal transmitted by the transmitting terminal may be received by two or more receiving terminals. Also, in the D2D communication according to the present invention, the first terminal transmits data and control signals in the uplink, and the second terminal receives the uplink data and the control signal transmitted from the first terminal. Thus, an SC-FDMA symbol may be used to construct a physical channel carrying data and control signals.

4 is a diagram for explaining the concept of a cellular network-based D2D communication applied to the present invention.

Referring to FIG. 4, a cellular communication network including a first base station 410, a second base station 420, and a first cluster 430 is configured. The first terminal 411 and the second terminal 412 belonging to the cell provided by the first base station 410 perform communication through a normal access link (cellular link) through the first base station 410. [ This is an In-coverage-single-cell inter-terminal communication scenario. Meanwhile, the first terminal 411 belonging to the first base station 410 can perform terminal-to-terminal communication with the fourth terminal 421 belonging to the second base station 420. This is an In-coverage-multi-cell inter-terminal communication scenario. The fifth terminal 431 other than the network coverage may create one cluster 430 together with the sixth terminal 432 and the seventh terminal 433 to perform communication with the terminals. This is an out-of-coverage inter-terminal communication scenario. Also, the third terminal 413 can perform terminal-to-terminal communication with the sixth terminal 432, which is a partial-coverage terminal-to-terminal communication scenario. In this way, the inter-terminal communication link can be performed between devices having the same cell as a serving cell, between devices having different cells as a serving cell, and can be performed between a device connected to a serving cell and a serving cell ), Or between devices not connected to a serving cell. In particular, D2D communication may be required between devices outside of network coverage for the purpose of public safety and the like.

In order to perform D2D data transmission / reception through D2D communication, relevant control information must be transmitted / received between the terminals. The relevant control information may be referred to as a Scheduling Assignment (SA). The Rx terminal may perform a configuration for receiving D2D data based on the SA. The SA includes, for example, a New Data indicator (NDI), a Transmit UE Identification (Tx) ID, a Redundancy Version indicator, an MCS indication, a Resource Allocation , And a power control indication.

Here, NDI indicates whether the current transmission is a repetition of data, i.e., retransmission or new. The receiver can combine the same data based on NDI. The Tx terminal ID indicates the ID of the transmitting terminal. The RV indicator indicates the redundancy version by specifying the different starting points in the circular buffer for the encoded buffer reading. Based on the RV indicator, the transmitting terminal may choose various redundancy versions for the repetition of the same packet. The MCS indication indicates the MCS level for D2D communication. The resource allocation instruction indicates to which time / frequency physical resource the corresponding D2D data is allocated to be transmitted. The power control instruction will be a command for the terminal that has received the information to control the size of power appropriate for the D2D transmission.

For a terminal supporting D2D communication, a radio resource for D2D communication may be an uplink channel of the (cellular) radio communication system. In this case, the SA and data for the D2D communication may be transmitted based on the structure of the PUSCH among the uplink physical channels of the wireless communication system. That is, for the physical channel for D2D communication, the PUSCH structure can be reused. For example, a 24-bit CRC (Cyclic Redundancy Check) can be inserted in the physical channel for D2D communication, and turbo coding can be used. Rate matching may also be used for bit size matching and generating multiple transmissions. Scrambling can be used for interference randomization. Also, a PUSCH demodulation reference signal (DMRS) can be used for channel estimation.

At the perspective of the Tx terminal, the Tx terminal may operate in two modes for resource allocation.

Mode 1 is the case where a base station or relay node (hereinafter referred to as a base station, which may include a relay node) schedules certain resource (s) for D2D communication. That is, in mode 1, the specific resource (s) used for transmitting the D2D data and the D2D control information (SA) of the Tx terminal is designated by the base station or the relay node. Mode 2 is a case where the UE directly selects a specific resource (s) in the resource pool. That is, in mode 2, the Tx terminal directly designates specific resource (s) for transmission of D2D data and D2D control information.

A D2D capable terminal supports at least mode 1 for in-coverage D2D communication. A D2D capable terminal supports mode 2 for at least out-of-coverage or edge-of-coverage D2D communication.

D2D communications may include unicast communications, groupcast communications, and broadcast communications. In this case, the Tx terminal performing the D2D broadcast communication may be called a broadcasting terminal. For D2D broadcast communication, an SA indicating the location of the resource (s) for reception of an associated physical channel carrying D2D data must be transmitted by the broadcasting terminal. The resource (s) may be implicitly and / or explicitly indicated based on the content of the SA resource or SA.

In Mode 1, the location of the resource (s) for transmission of the (by) SA by the broadcasting terminal and the location of the resource (s) for transmission of the D2D data is given by the base station. That is, the D2D SA grant and the D2D data grant are given from the base station to the terminal. Here, the D2D SA grant instructs the Tx terminal to transmit the D2D SA, and the D2D data grant instructs the Tx terminal to transmit the D2D data. The D2D data grant may be transmitted concurrently with or at the same time as the SA grant. The D2D SA grant and the D2D data grant may be transmitted via the PDCCH / EPDCCH.

In Mode 2, the resource pool for the SA may be pre-configured and / or semi-statically allocated. In this case, the Tx UE can select a resource for the SA in the resource pool for transmission of the SA.

If the Tx terminal is located outside of coverage, the resources for D2D broadcast data are selected in the resource pool. In this case, the resource pool may be pre-configured or semi-statically allocated.

The Tx terminal must instruct the at least one D2D Rx terminal with the control information SA associated with the D2D data before transmitting the D2D data to at least one Rx terminal (broadcast / group cast / unicast). Due to the nature of the D2D communication link, it does not currently support HARQ-ACK feedback for at least D2D broadcast communication. Also, the D2D communication link is in a half-duplex constraint state. That is, it does not support simultaneous transmission and reception on the same time or subframe. Multiple Transmission Opportunity (MTO) can be defined for reliable and flexible D2D communication in such an environment. One or more SAs and / or data transmissions may be performed within one multiplex transmission opportunity. That is, the same SA and / or data may be transmitted in duplicate within one multiplex transmission opportunity, and other (or multiple) SAs and / or data may be transmitted. Herein, another (or multiple) SA (and / or data) is transmitted includes not only cases where all of the SAs (and / or data) transmitted in the multiple transmission opportunity are different, but only some others. The multiple transmit opportunity may be referred to as a multiple SA transmit opportunity for SA transmissions and multiple data transmit opportunities for data transmissions.

In addition, Resource Pattern for Transmission (RPT), which is a pattern for time and / or frequency resources for multiple transmission opportunities, may be used.

For example, for control information for D2D communication, an SA corresponding to the control information may be transmitted from a resource corresponding to the RPT. At this time, for an RPT which is a pattern of time and / or frequency resources for multiple transmission opportunities, one SA may be transmitted in one RPT, and a plurality of SAs may be transmitted.

Also, for data for D2D communication, a data transmission block (TB), which is a unit of transmission of the data, can be transmitted from a resource corresponding to the RPT. At this time, for RPT, which is a pattern of time and / or frequency resources for multiple transmission opportunities, one data TB may be transmitted in one RPT, and a plurality of data TBs may be transmitted.

The RPT can be implicitly or explicitly signaled by the base station (or relay node) in the mode 1 resource allocation of D2D. And may be signaled via SA in case of RPT for the data TB for Mode 1 and Mode 2 resource allocation.

The D2D communication may transmit a signal from the Tx terminal to the Rx terminal through the cellular uplink resource, and in this case, the signal may cause interference to the cellular network (for example, a WAN (Wide Area Network)). Where the WAN includes a Long Term Evolution (LTE) -based network (including LTE-A (LTE-Advnaced)).

In the cellular network, the interference is controlled by adjusting the transmission power of each terminal based on the TPC command as described above. However, the D2D communication does not disclose a specific configuration or method for power control. Power control for D2D transmission is required to minimize the influence of interference and interference on the cellular network and to support D2D communication as well. In particular, first layer (L1) control signaling overhead for D2D communication is low, such as using multiple transmission opportunities through a single grant, and power control must be performed for efficient D2D transmission . Also, for D2D discovery or D2D synchronization, first layer power control signaling should be considered.

D2D physical channels to be considered for power control for D2D transmission can be divided as follows. D2D SA transmission channel, D2D data transmission channel, D2D discovery channel, D2D synchronization channel (if supported). Here, the D2D synchronization channel may be referred to as a PD2DSCH (Physical D2D Synchronization Channel). The present invention proposes a power control signaling method for D2D communication considering the above D2D physical channels. Hereinafter, D2D communication may include D2D SA / data transmission, D2D discovery signal transmission, and D2D synchronization signal transmission.

1. D2D power control signaling method based on DCI format 3 / 3A _with New RRC signaling

According to the current standard, the DCI format 3 / 3A has the same size as the DCI format 0 and the size of the DCI format 3 / 3A is set to "N" (DCI format 3), "M" (DCI format 3A), and uses it for power control instruction to the terminals. Each terminal can recognize a TPC command for the corresponding terminal based on the index indicated by the tpc-Index field included in the RRC signaling.

Example 1-1)

In the embodiment of the present invention, a method of indicating an additional TPC command for D2D communication based on the existing TPC-PUCCH-RNTI / TPC-PUSCH-RNTI is proposed. In the past, a TPC index was used for power control on a WAN UL channel (PUSCH or PUCCH), and in the embodiment of the present invention, a D2D TPC index can be added for power control for D2D transmission.

That is, according to an embodiment of the present invention, the RRC signaling includes a D2D index for D2D transmission. In this case, the TPC-PDCCH-Config information element included in the RRC signaling may include the following syntax.

Referring to Table 5, the TPC-PDCCH-Config information element includes a tpc-Index field, and the tpc-Index field indicates a TPC index parameter. The TPC index parameter includes indexOfFormat3 information, indexOfFormat3A information, indexOfFormat3_D2D information, and indexOfFormat3A_D2D information. The indexOfFormat3 information indicates an index of a TPC command number for WAN communication when the DCI format 3 is used, and the indexOfFormat3A information indicates an index of a TPC command number for WAN communication when the DCI format 3A is used. The indexOfFormat3_D2D information indicates an index of a TPC command number for D2D communication when DCI format 3 is used, and the indexOfFormat3A_D2D information indicates an index of a TPC command number for D2D communication when the DCI format 3A is used.

In Table 5, the indexOfFormat3 information and the indexOfFormat3_D2D information have the same category value, and the indexOfFormat3A information and the indexOfFormat3A_D2D information have the same category value. When WAN communication and D2D communication are indicated through the same DCI format, the TPC index for WAN communication and the TPC index for D2D communication must have different values. The TPC index for WAN communication and the TPC index for D2D communication can be controlled by the base station.

For power control of the D2D communication based on the RRC signaling including the above parameters, a TPC command can be indicated. The TPC command can be applied to all D2D communications (transmissions or signals) or to some D2D communications (transmissions or signals).

Example 1-2)

In the embodiment 1-1 described above, when the RRC signaling and the TPC command based on the DCI format 3 / 3A are acquired, the D2D signals (for example, D2D SA signal, D2D data signal, D2D search signal, ), It is assumed that the corresponding TPC command is applied to some or all of them. If power control is applied to a specific D2D signal, a setting indicating a specific D2D signal should be added.

In this case, for example, the TPC-PDCCH-Config information element included in the RRC signaling may include the following syntax.

Referring to Table 6, the TPC-PDCCH-Config information element includes a tpc-Index field, and the tpc-Index field indicates a TPC index parameter. The TPC-Index parameter includes indexOfFormat3 information, indexOfFormat3A information, indexOfFormat3_D2D_Data information, and indexOfFormat3A_D2D_SA information. The indexOfFormat3 information indicates an index of a TPC command number for WAN communication when the DCI format 3 is used, and the indexOfFormat3A information indicates an index of a TPC command number for WAN communication when the DCI format 3A is used. The indexOfFormat3_D2D_Data information indicates an index of a TPC command number for D2D data transmission when DCI format 3 is used, and the indexOfFormat3A_D2D_SA information indicates an index of a TPC command number for D2D SA transmission when DCI format 3A is used. Of course, as an example, the indexOfFormat3_D2D_Data information may be replaced with the indexOfFormat3_D2D_SA information, and the indexOfFormat3A_D2D_SA information may be replaced with the indexOfFormat3A_D2D_Data information.

When WAN communication and D2D communication are indicated through the same DCI format, the TPC index for WAN communication and the TPC index for D2D communication must have different values. The TPC index for WAN communication and the TPC index for D2D communication can be controlled by the base station.

And may indicate a TPC command for a specific D2D signal based on the RRC signaling including the above parameters.

Examples 1-3)

Embodiment 1-3 is based on the RRC signaling shown in Table 5 described in Embodiment 1-1, and it is determined whether the CRC parity bits of the PDCCH carrying the corresponding DCI format 3 / 3A are scrambled with the TPC-PUCCH-RNTI, TPC-PUSCH-RNTI based on whether or not scrambled with the TPC-PUSCH-RNTI, the TPC command for D2D data transmission or the TPC command for D2D SA transmission. For example, a terminal supporting D2D communication can recognize a TPC command included in DCI format 3 / 3A scrambled with TPC-PUCCH-RNTI as a TPC command for D2D data transmission (power control related to D2D data transmission). On the other hand, a terminal supporting D2D communication can recognize a TPC command included in DCI format 3 / 3A scrambled with TPC-PUSCH-RNTI as a TPC command for power control (D2D SA transmission). Of course, this is an example of the transmission of a specific D2D signal by different combinations between the TPC-PUCCH / PUSCH-RNTI and the above-described D2D signals (e.g., D2D SA signal, D2D data signal, D2D search signal, D2D sync signal) Gt; TPC < / RTI >

2. D2D power control signaling method based on DCI format 3 / 3A _with New TPC-D2D-RNTI

This method proposes a new RNTI for power control of D2D communication.

Example 2-1)

Embodiment 2-1 proposes a new TPC-D2D-RNTI for power control of D2D communication. In this case, the CRC parity bits of the PDCCH carrying the corresponding DCI format 3 / 3A are scrambled with the TPC-D2D-RNTI, and only the terminal (s) to which the RNTI value is assigned carry the PDCCH carrying the corresponding DCI format 3 / Can be confirmed. According to the present method, the DCI format 3 / 3A does not use the index of the TPC command for WAN communication and the index of the TPC command for the D2D communication, and independently uses the index in the entire category (1 to N (or M) In this case, the terminal must additionally perform one or more CRC checks on the new TPC-D2D-RNTI in order to receive the TPC command for D2D communication. Thus, according to the present method, a new D2D dedicated TPC Command transmission can be performed and a TPC command for D2D communication can be received by increasing some complexity from a terminal point of view.

In this case, the TPC-PDCCH-Config information element included in the RRC signaling may include the following syntax.

Referring to Table 7, the TPC-PDCCH-Config information element includes a tpc-RNTI field and a tpc-Index field. The tpc-RNTI field indicates an RNTI value used for power control of D2D communication based on DCI format 3 / 3A. Herein, the RNTI means TPC-D2D-RNTI. The tpc-Index field indicates a TPC index parameter. The TPC index parameter includes indexOfFormat3_D2D information and indexOfFormat3A_D2D information. The indexOfFormat3_D2D information indicates an index of a TPC command number for D2D communication when DCI format 3 is used, and the indexOfFormat3A_D2D information indicates an index of a TPC command number for D2D communication when the DCI format 3A is used.

In Table 5, the indexOfFormat3 information and the indexOfFormat3_D2D information have the same category value, and the indexOfFormat3A information and the indexOfFormat3A_D2D information have the same category value. When WAN communication and D2D communication are indicated through the same DCI format, the TPC index for WAN communication and the TPC index for D2D communication must have different values. The TPC index for WAN communication and the TPC index for D2D communication can be controlled by the base station.

For power control of the D2D communication based on the RRC signaling including the above parameters, a TPC command can be indicated. The TPC command can be applied to all D2D communications (transmissions or signals) or to some D2D communications (transmissions or signals).

Example 2-2)

In Embodiment 2-2, another RNTI value is defined by distinguishing the D2D signals (for example, the D2D SA signal, the D2D data signal, the D2D search signal, and the D2D synchronization signal) for a specific D2D signal. For example, TPC-D2D_Data-RNTI may be defined for power control for D2D data signal transmission and TPC-D2D_SA-RNTI may be defined for power control for D2D SA signal transmission. Also, TPC-D2D_D-RNTI may be defined for power control for D2D search signal transmission, and TPC-D2D_S-RNTI may be defined for power control for D2D synchronization signal transmission.

According to the embodiment 2-2, the BS can transmit RRC signaling as shown in Table 7, and the UE can know which RNTI is the RNTI based on the RNTI value indicated by the tpc-RNTI field, A CRC check based on the RNTI may be performed to obtain a TPC command for a specific D2D signal.

According to the embodiments of the present invention described above, the network is capable of indicating TPC commands for D2D communication utilizing RRC signaling according to the present invention and DCI format 3 / 3A to D2D enabled terminals in coverage. Through power control for D2D communication, it is possible to mitigate the interference to WAN communication within the cell coverage, and to perform efficient D2D communication.

5 is a flow chart illustrating a method for supporting power control for D2D communication in accordance with the present invention.

Referring to FIG. 5, the base station transmits an RRC message including a TPC-RNTI parameter and a TPC index parameter to the Tx terminal (S500). The RRC message may be an RRC Connection Reconfiguration message. The RRC message includes a TPC-PDCCH-Config information element. The TPC-PDCCH-Config information element may be as shown in Table 5, Table 6, or Table 7 above.

For example, the TPC index parameter may indicate an index of a TPC command for D2D communication for DCI format 3 / 3A (Embodiment 1-1). A TPC command may be detected based on the index of the TPC command number. In this case, it is possible to detect a TPC command for power control for transmission of a specific D2D signal according to whether the TPC-RNTI indicates a TPC-PUCCH-RNTI or a TPC-PUSCH-RNTI (Embodiment 1-3) . The specific D2D signal may include at least one of a D2D SA signal, a D2D data signal, a D2D search signal, and a D2D synchronization signal.

As another example, the TPC index parameter may indicate an index of a TPC command for transmission of a specific D2D signal for DCI format 3 / 3A (embodiment 1-2).

As another example, the TPC-RNTI parameter may indicate a new TPC-D2D-RNTI for D2D communication (embodiment 2-1).

As another example, the TPC-RNTI parameter may indicate an RNTI for a specific D2D signal (embodiment 2-2). For example, the TPC-RNTI parameter may indicate at least one of TPC-D2D_Data-RNTI, TPC-D2D_SA-RNTI, TPC-D-RNTI and TPC-S-RNTI.

The base station transmits the PDCCH having the DCI format 3 / 3A to the Tx terminal (S510). The DCI format 3 / 3A may be as shown in Table 2 / Table 3 above. In the DCI format 3 / 3A, CRC parity bits are scrambled with a specific RNTI to form the PDCCH.

The Tx terminal detects a TPC command for D2D communication based on the RRC message and the DCI format 3 / 3A (S520). The Tx UE can detect the PDCCH based on a specific RNTI acquired based on the TPC-RNTI parameter included in the RRC message, and based on the TPC index parameter, transmits the DCI format 3 / 3A included in the PDCCH And detect a TPC command for D2D communication for the included terminal.

The Tx terminal performs transmission power control for D2D communication based on the TPC command (S530). In this case, the Tx terminal may perform power control based on the TPC command for a specific D2D signal, based on whether the TPC index parameter indicates a specific D2D signal. Alternatively, based on whether the particular RNTI indicates a particular D2D signal, it may perform power control based on the TPC command for a particular D2D signal.

The Tx terminal transmits the D2D signal to the receiving terminal based on the transmission power control (S540). The Tx terminal may apply the transmission power control only to a specific D2D signal. In this case, the specific D2D signal includes at least one of a D2D SA signal, a D2D data signal, a D2D search signal, and a D2D synchronization signal. Are as described above.

Although not shown in FIG. 5, the terminal may receive the D2D SA grant and the D2D data grant from the base station. If the D2D signal is a D2D SA signal or a D2D data signal, the terminal may generate the D2D SA signal based on the D2D SA grant and transmit the D2D SA signal to the Rx terminal or generate a D2D data signal based on the D2D data grant To the Rx terminal.

6 is a block diagram illustrating a wireless communication system supporting D2D communication according to the present invention.

Referring to FIG. 6, a base station 600 includes a processor 605, a memory 610, and an RF unit (radio frequency) unit 615. The memory 610 is coupled to the processor 605 and stores various information for driving the processor 605. [ The RF unit 615 is connected to the processor 605 to transmit and / or receive a radio signal. The processor 605 implements the proposed functions, procedures and / or methods for performing the operations according to the present invention. The operation of the base station in the above embodiments may be implemented by the processor 605. [

Specifically, the processor 605 may generate the RRC message and the DCI format 3 / 3A, which are published herein, and transmit the generated RRC message and the DCI format 3 / 3A to the Tx terminal 630 through the RF unit 615. In the DCI format 3 / 3A, the CRC parity bits may be scrambled with a specific RNTI and transmitted to the Tx terminal 930 in the form of a PDCCH.

The Tx terminal 630 includes a processor 635, a memory 640, and an RF unit 645. The memory 640 is coupled to the processor 635 and stores various information for driving the processor 635. [ The RF unit 645 is coupled to the processor 635 to transmit and / or receive wireless signals. The processor 645 implements the proposed functions, procedures and / or methods for performing the operations according to the present invention. The operation of the Tx terminal 630 in the above-described embodiment may be implemented by the processor 635. [

The RF unit 645 receives the RRC message including the TPC-RNTI parameter and the TPC index parameter. Also, the RF unit 945 receives the DCI format 3 / 3A. The processor 935 may detect a PDCCH carrying the DCI format 3 / 3A based on the specific RNTI included in the TPC-RNTI parameter.

Processor 935 detects TPC commands for D2D communication based on the RRC message and the DCI format 3 / 3A or for transmission of a specific D2D signal. The processor 935 performs power control based on the detected TPC command and can perform the D2D communication or the transmission of the specific D2D signal through the RF unit 945. [

For example, the RF unit 645 may receive the D2D SA grant and the D2D data grant from the base station 600, and the processor 935 may receive the D2D SA signal and the D2D data based on the D2D SA grant and the D2D data grant Signal can be generated. The processor 935 performs power control for transmitting the D2D SA signal based on the detected TPC command when the specific signal is a D2D SA signal and performs transmission of the D2D SA signal through the RF unit 945 . The processor 935 performs power control for transmitting the D2D data signal based on the detected TPC command when the specific signal is a D2D data signal and performs transmission of the D2D data signal through the RF unit 945 .

The Rx terminal 660 includes a processor 665, a memory 670, and an RF section 675. The memory 670 is coupled to the processor 665 and stores various information for driving the processor 665. [ RF section 675 is coupled to processor 665 to transmit and / or receive wireless signals. Processor 665 implements a set of functions, processes, and / or methods for performing D2D communications.

The RF unit 645 receives the (specific) D2D signal whose transmission power is controlled from the Tx terminal 630. [

The processor may comprise an application-specific integrated circuit (ASIC), other chipset, logic circuitry and / or a data processing device. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices. The RF unit may include a baseband circuit for processing the radio signal. When the embodiment is implemented in software, the above-described techniques may be implemented with modules (processes, functions, and so on) that perform the functions described above. The module is stored in memory and can be executed by the processor. The memory may be internal or external to the processor and may be coupled to the processor by any of a variety of well known means.

In the exemplary system described above, although the methods are described on the basis of a flowchart or a flowchart as a series of steps or blocks, the present invention is not limited to the order of steps, and some steps may be performed in a different order than the steps described above Can occur at the same time. It will also be appreciated by those skilled in the art that the steps depicted in the flowcharts or flowcharts are not exclusive and that other steps may be included or that one or more steps in a flowchart or flowchart may be deleted without affecting the scope of the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (19)

A power control method for D2D (Device to Device) communication performed by a base station (evolved-NodeB, eNB)
Generating a Radio Resource Control (RRC) message including a TPC (Transmission Power Control) -RNTI (Radio Network Temporary Identifier) parameter and a TPC index parameter;
Transmitting the generated RRC message to a transmission (Tx) user equipment (UE);
Generating a physical downlink control channel (PDCCH) having a downlink control information (DCI) format 3 or 3A including a TPC command; And
And transmitting the generated PDCCH to the Tx terminal,
Wherein at least one of the TPC-RNTI parameter and the TPC index parameter indicates that the TPC command included in the DCI format 3 or 3A is a TPC command for D2D communication. The method according to claim 1,
Wherein the RRC message includes a TPC-PDCCH-Config information element (IE), and the TPC-RNTI parameter and the TPC index parameter are included in the TPC-PDCCH-Config information element. . 3. The method of claim 2,
Wherein the TPC index parameter indicates an index of a TPC command for the D2D communication for the DCI format 3 or 3A. The method of claim 3,
(TPC-RNTI) indicating whether a TPC-PUCCH (Physical Uplink Control Channel) -RNTI or a TPC-PUSCH (Physical Uplink Shared Channel) -RNTI indicates whether the TPC command is transmitted through D2D communication Indicating that it is applied to a specific D2D signal among the signals,
Wherein the specific D2D signal includes at least one of a D2D SA signal, a D2D data signal, a D2D search signal, and a D2D synchronization signal. 3. The method of claim 2,
The TPC index parameter indicates an index of the TPC command for transmission of a specific D2D signal for the DCI format 3 or 3A,
Wherein the specific D2D signal includes at least one of a D2D SA signal, a D2D data signal, a D2D search signal, and a D2D synchronization signal. 3. The method of claim 2,
And the TPC-RNTI parameter indicates a TPC-D2D-RNTI for the D2D communication. 3. The method of claim 2,
Wherein the TPC-RNTI parameter indicates at least one of a TPC-D2D_Data-RNTI, a TPC-D2D_SA (Scheduling Assignment) -RNTI, a TPC-D (Discovery) -RNTI, and a TPC-S (Synchronization) Power control method. (Tx) A method for supporting D2D (Device to Device) communication performed by a terminal UE,
Comprising: receiving from a base station (eNB) an RRC (Radio Resource Control) message including a TPC (Transmission Power Control) -RNTI (Radio Network Temporary Identifier) parameter and a TPC index parameter;
Comprising: receiving from a base station a PDCCH (Physical Downlink Control Channel) having a downlink control information (DCI) format 3 or 3A including a TPC command;
Detecting the PDCCH based on a specific RNTI included in the TPC-RNTI parameter; And
Detecting a TPC command for D2D communication from the DCI format 3 or 3A based on at least one of the TPC-RNTI parameter and the TPC index parameter. 9. The method of claim 8,
Performing transmit power control for the D2D communication or a specific D2D signal based on the TPC command;
And performing transmission of the D2D communication or the specific D2D signal based on the transmission power control. 10. The method of claim 9,
Wherein the RRC message includes a TPC-PDCCH-Config information element (IE), and the TPC-RNTI parameter and the TPC index parameter are included in the TPC-PDCCH-Config information element. . 11. The method of claim 10,
Detecting the TPC command based on an index of a TPC command for the D2D communication for the DCI format 3 or 3A included in the TPC index parameter. 12. The method of claim 11,
(TPC-RNTI) indicating whether a TPC-PUCCH (Physical Uplink Control Channel) -RNTI or a TPC-PUSCH (Physical Uplink Shared Channel) -RNTI indicates whether the TPC command is transmitted through D2D communication Detecting the application of the specific D2D signal among the signals,
Wherein the specific D2D signal includes at least one of a D2D SA signal, a D2D data signal, a D2D search signal, and a D2D synchronization signal. 11. The method of claim 10,
Detecting the TPC command based on an index of the TPC command for transmission of the specific D2D signal for the DCI format 3 or 3A included in the TPC index parameter,
Wherein the specific D2D signal includes at least one of a D2D SA signal, a D2D data signal, a D2D search signal, and a D2D synchronization signal. 11. The method of claim 10,
And the specific RNTI included in the TPC-RNTI parameter is a TPC-D2D-RNTI for the D2D communication. 11. The method of claim 10,
The specific RNTI included in the TPC-RNTI parameter is at least one of a TPC-D2D_Data-RNTI, a TPC-D2D_SA (Scheduling Assignment) -RNTI, a TPC-D (Discovery) -RNTI, and a TPC-S (Synchronization)
And performs transmission power control on a specific D2D signal based on the specific RNTI. 11. The method of claim 10,
Receiving a D2D Scheduling Assignment (SA) grant from the base station;
Generating a D2D SA signal based on the D2D SA grant,
And the specific D2D signal is a D2D SA signal. 11. The method of claim 10,
Receiving a D2D data grant from the base station;
Generating a D2D data signal based on the D2D data grant,
And the specific D2D signal is a D2D data signal. A base station (evolved-NodeB, eNB) that supports power control for D2D (Device to Device) communication,
(Radio Resource Control) message including a TPC (Transmission Power Control) -RNTI (Radio Network Temporary Identifier) parameter and a TPC index parameter, generates DCR (Downlink Control Information) format 3 including PC commands A physical downlink control channel (PDCCH) having a physical uplink control channel (PDCCH); And
And an RF unit for transmitting the generated RRC message and the PDCCH to a transmission (Tx) user equipment (UE)
Wherein at least one of the TPC-RNTI parameter and the TPC index parameter indicates that the TPC command included in the DCI format 3 or 3A is a TPC command for D2D communication. A transmission (Tx) terminal (UE) supporting power control for D2D (Device to Device) communication,
(Radio Network Control) message including a TPC (Transmission Power Control) -RNTI (Radio Network Temporary Identifier) parameter and a TPC index parameter from a base station (eNB) Information) An RF unit that receives a PDCCH (Physical Downlink Control Channel) having a format of 3 or 3A from the BS; And
Detecting a PDCCH based on a specific RNTI included in the TPC-RNTI parameter; detecting a TPC command for D2D communication from the DCI format 3 or 3A based on at least one of the TPC-RNTI parameter and the TPC index parameter; The processor comprising:

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