WO2015115738A1

WO2015115738A1 - Method and apparatus for operating transmission/reception terminal through resource allocation of d2d communication in wireless communication system

Info

Publication number: WO2015115738A1
Application number: PCT/KR2014/012996
Authority: WO
Inventors: 류현석; 박승훈; 박정호; 유현규; 정철
Original assignee: 삼성전자주식회사
Priority date: 2014-01-29
Filing date: 2014-12-29
Publication date: 2015-08-06

Abstract

The embodiments of the present invention provide a method and an apparatus for operating a transmission/reception terminal through a resource allocation of a device to device (D2D) communication in a wireless communication system. According to one embodiment of the present invention, a method for operating a transmission terminal through a resource allocation of a device to device (D2D) communication in a wireless communication system comprises the steps of: mapping D2D control information for the D2D communication to at least any one of a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH) and demodulation-reference signals (DM-RS); and transmitting, to a reception terminal, the D2D control information mapped to at least any one of the PDCCH, the PUSCH and the DM-RS.

Description

Operation method and apparatus of transmitting / receiving terminal through resource allocation of D2D communication in wireless communication system

The present invention relates to an apparatus and a method for supporting a device to device (D2D), and more particularly, a technology related to resource allocation for communication in D2D and control information transmission therefor.

Recently, as the spread of smartphones is accelerated, various application services using smartphones are being activated, and this aspect is expected to accelerate further. Therefore, various technologies are emerging to effectively prevent the increase of data caused by these various application services in cellular systems. For example, as a large amount of mobile contents are used, device-to-device communication (D2D) for distributing the load of a base station efficiently by using the proximity of a mobile communication terminal is drawing attention. An example of this is the current D2D ^{3GPP (3 rd Generation Partnership Project)} LTE is adopted (Long Term Evolution) of the release study item 12 is being standardized in RAN1 in progress.

In LTE, D2D communication is being standardized for the purpose of public safety. That is, D2D communication aims to achieve reliable communication between terminals in a situation where a base station is collapsed due to a natural disaster such as an earthquake or tsunami. In addition, D2D communication in the areas outside the base station's coverage (e.g., shaded areas and base station coverage halls) during the emergency operations such as fire and terror suppression must be seamlessly communicated between terminals without the help of the base station. . Therefore, it is important to secure link reliability, rather than to increase bandwidth efficiency or system throughput, which was a requirement of existing cellular communications.

Conventional cellular systems support various kinds of control information. However, D2D communication, which is currently being standardized for LTE Rel-12, may not require all such control information. For example, D2D communication is currently aimed at groupcast / broadcast communication, rather than unicast communication, which is commonly used in cellular, so that some form of L1 (layer 1: PHY) / L2 (layer 2: MAC, It was already agreed at the 3GPP RAN1 / RAN2 meeting that no PDCP, RLC) feedback would be performed. Under these assumptions, it is necessary to study what control information is required for D2D groupcast / broadcast communication.

In addition, the existing cellular frequency division duplexing (FDD) system uses different frequency bands for downlink and uplink transmission / reception (for example, downlink is f ₁ band and uplink is f ₂ band). Therefore, the base station transmits in the f ₁ band, receives the f ₂ band, and the terminal receives the f ₂ transmission in the band, f ₁ band. Meanwhile, in the existing cellular time division duplexing (TDD) system, downlink and uplink are performed in the same frequency band, but they are time-divided. That is, the uplink and downlink transmission is characterized by being divided on the frequency or time axis.

However, D2D communication is performed via the uplink. For example, assuming D2D communication operating in an FDD system, a D2D transmitter transmits in an uplink f ₂ band and a D2D receiver receives in an uplink f ₂ band. Similarly, in the case of D2D communication operating in a TDD system, the D2D transmitter transmits using an uplink subframe and the D2D receiver receives using an uplink subframe. Since the D2D communication is performed through the uplink, it may be considered to reuse the uplink control information (UCI) and the physical uplink control channel (PUCCH) used in the existing cellular system as control information and control channel for the D2D. However, in LTE, uplink uses SC-FDMA (Single Carrier-Frequency Division Multiple Access), which has superior peak-to-average power ratio (PAPR) characteristics compared to orthogonal frequency-division multiple access (OFDMA) regardless of FDD / TDD. do. When one UE simultaneously transmits the PUCCH and the PUSCH, it is not preferable to transmit the D2D control information through the PUCCH because it cannot maintain the characteristics of the single carrier. Therefore, a new type of control channel design is needed for D2D.

In addition, in the existing cellular system, the base station centralized resource allocation based on various feedback information from the terminal. However, in D2D communication, since there is no feedback information between terminals, a method for distributed resource allocation is needed. In distributed resource allocation, there is no coordinator that can arbitrate the resource allocation. Therefore, when allocating a resource, a resource collision may occur due to the same resource allocation. Therefore, a solution to this problem is needed.

The problem to be solved by the present invention is the design and resource allocation of control information and control channel for D2D communication, the content and size of the control information, the design of the control channel for transmitting the control information, and distributed among the terminals The present invention relates to a method and apparatus for operating a transmitting / receiving terminal through resource allocation of device to device (D2D) communication in a wireless communication system for allocating resources.

According to an embodiment of the present invention for solving the above problems, in a wireless communication system, a method of operating a transmitting terminal through resource allocation of device to device (D2D) communication, the D2D control information for the D2D communication PDCCH Mapping to at least one of Physical Downlink Control CHannel, Physical Uplink Shared CHannel, and Demodulation-Reference Signals (DM-RS); And transmitting the D2D control information mapped to at least one of the PDCCH, the PUSCH, and the DM-RS to a receiving terminal.

According to another embodiment of the present invention for solving the above problems, in the wireless communication system in the operating device of the transmitting terminal through the resource allocation of the D2D (Device to Device) communication, the D2D control information for the D2D communication A mapping processor for mapping to at least one of a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), and a demodulation-reference signal (DM-RS); And a transmitter for transmitting the D2D control information mapped to at least one of the PDCCH, the PUSCH, and the DM-RS to a receiving terminal.

According to another embodiment of the present invention for solving the above problems, in a method of operating a receiving terminal through resource allocation of device to device (D2D) communication in a wireless communication system, the D2D control information for the D2D communication is When the PDCCH is mapped and transmitted to at least one of a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), and a demodulation-reference signal (DM-RS), the PDCCH, the PUSCH, and the D2D control information are mapped. Receiving at least one of the DM-RSs; And extracting the D2D control information by restoring at least one of the received PDCCH, the PUSCH, and the DM-RS.

In various embodiments of the present disclosure, the extracting of the D2D control information may include: out of a groupcast ID and a broadcast ID for a group defining a range of the D2D communication when the D2D control information is received mapped to a symbol of the PDCCH. At least one can be extracted from the D2D control information.

In various embodiments of the present disclosure, the extracting of the D2D control information may include demultiplexing the D2D control information from the modulated data information of the PUSCH when the D2D control information is mapped and received from a symbol of the PUSCH. have.

In various embodiments of the present disclosure, the extracting of the D2D control information may extract new data indicator information as the D2D control information when the D2D control information is mapped and received in the DM-RS. .

Extracting the new data identifier information may be performed using a parameter value having a size of 1 bit.

According to another embodiment of the present invention for solving the above problems, in the operation apparatus of the receiving terminal through the resource allocation of the device to device (D2D) communication in a wireless communication system, the D2D control information for the D2D communication is When the PDCCH is mapped and transmitted to at least one of a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), and a demodulation-reference signal (DM-RS), the PDCCH, the PUSCH, and the D2D control information are mapped. Receiving unit for receiving at least one of the DM-RS; And a control information extracting unit which extracts the D2D control information by restoring at least one of the received PDCCH, the PUSCH, and the DM-RS.

According to another embodiment of the present invention for solving the above problems, in a wireless communication system, a method of operating a transmitting terminal through resource allocation of device to device (D2D) communication, a plurality of resource blocks based on a predetermined time Setting up a resource structure to include at least one resource pool having Resouce Blocks; Allocating a resource for a signal to be transmitted by shifting the resource blocks included in the resource pool on a time axis every predetermined time; And transmitting the signal to a receiving terminal by using the allocated resource.

In various embodiments, the allocating of the resource may shift the resource blocks such that the shift interval of the resource pool is different from the shift interval of another resource pool at every predetermined time.

In the process of allocating the resource, when the predetermined time is a sum of a predetermined number of times, a unit cycle, the resource may be allocated by grouping the unit cycle.

According to another embodiment of the present invention for solving the above problems, in a wireless communication system, a plurality of resource blocks on the basis of a predetermined time in the operating device of the transmitting terminal through the resource allocation of device to device (D2D) communication A resource structure setting unit configured to set a resource structure to include at least one resource pool having Resouce Blocks; A resource allocator for allocating a resource for a signal to be transmitted by shifting the resource blocks included in the resource pool on a time axis every predetermined time; And a transmission interface unit for transmitting the signal to a receiving terminal by using the allocated resource.

According to another embodiment of the present invention for solving the above problems, in a wireless communication system, a method of operating a receiving terminal through resource allocation of device to device (D2D) communication, a plurality of resource blocks based on a predetermined time Receiving the signal from a transmitting terminal through the allocated resource when the resource for the signal is allocated according to a resource structure including at least one resource pool having Resume Blocks; And decoding the received signal.

The allocated resources may be allocated by grouping the unit periods when the periods in which the predetermined time is added up a predetermined number of times are unit cycles.

The receiving of the signal from the transmitting terminal may further include determining whether the signal is information related to its own group when the signal is transmitted through an allocated resource grouped by the unit period. May receive the signal if it corresponds to information associated with its group.

The determining of whether the signal is information related to its own group may include: receiving system frame information indicating information on allocated resources grouped by the unit period from the transmitting terminal, using the system frame information. It may be determined whether the signal is information related to its group.

The receiving of the signal from the transmitting terminal may further include switching to a standby mode when the signal is not information related to its group when the signal is transmitted through the allocated resource grouped by the unit period. Can be.

According to another embodiment of the present invention for solving the above problems, in the wireless communication system, the reception device for the operation of the receiving terminal through the resource allocation of the D2D (Device to Device) communication, the reception of the signal transmitted from the transmitting terminal A receiving interface unit for interfacing; When a resource for a signal is allocated according to a resource structure including at least one resource pool having a plurality of resource blocks based on a predetermined time, the transmitting terminal through the allocated resource A control unit controlling to receive the signal from the computer; And a decoder for decoding the received signal.

According to another embodiment of the present invention for solving the above problems, in a wireless communication system, a method for operating a transmitting terminal through resource allocation of device to device (D2D) communication, the signal for the D2D communication for a predetermined time Receiving them; Detecting energy levels of each of the resource blocks corresponding to the signals received during the predetermined time; And determining a transmission timing of data for the D2D communication according to a congestion class corresponding to the detected energy levels.

The determining of the transmission timing of the data for the D2D communication may include: comparing the energy levels with a predetermined threshold value; Determining the congestion class according to a result of comparing the energy levels with the predetermined threshold value; And determining the transmission timing corresponding to the determined congestion class.

The determining of the transmission timing may increase a transmission window size of the transmission timing as the degree of congestion according to the determined congestion level increases.

According to another embodiment of the present invention for solving the above problems, in the wireless communication system in the operating device of the transmitting terminal through the resource allocation of the device to device (D2D) communication, the signal for the D2D communication for a predetermined time Signal receiving unit for receiving the; An energy level detector for detecting an energy level of each of the resource blocks corresponding to the signals received during the predetermined time; And a transmission timing controller configured to determine a transmission timing of data for the D2D communication according to a congestion class corresponding to the detected energy levels.

According to the present invention, through the control information and control channel design for the D2D communication, the D2D communication can be made more reliable.

In addition, by reducing the overhead of control information for D2D communication, it is possible to transmit control information only by transmitting data channels without designing a separate physical control channel.

In addition, when resources are distributed among terminals, the terminal itself may determine its own situation and adjust a transmission opportunity to prevent resource collision in advance. Therefore, it can be effectively used to guarantee the reliability of D2D communication.

In addition, in the receiving terminal, the power consumption can be reduced by switching to the standby mode when it is not information related to its own group.

For a more complete understanding of the present invention and its effects, the following description will be made with reference to the accompanying drawings, wherein like reference numerals denote like parts.

1 is a reference diagram illustrating a structure of a PUCCH control channel to which the present invention is compared.

2 is a reference diagram illustrating a PDCCH control channel structure to which the present invention is compared.

3 is a reference diagram illustrating the physical processing of the PDCCH to be compared of the present invention.

4 is a reference diagram illustrating piggybacking control information on a PUSCH to be compared according to the present invention.

5 is a reference diagram illustrating physical processing for format A type of D2D control information (CI) through a PDCCH structure corresponding to an embodiment of the present invention.

FIG. 6 is a reference diagram illustrating piggyback processing for formats A and B of D2D control information (CI) through a PUSCH structure corresponding to an embodiment of the present invention.

FIG. 7 is a reference diagram illustrating mapping of format A type of D2D control information (CI) of FIG. 6 to PUSCH.

8A and 8B are reference diagrams illustrating a resource structure for resource allocation according to an embodiment of the present invention.

9 is a reference diagram illustrating a random back-ff operation in WiFi to which the present invention is compared.

FIG. 10 is a reference diagram illustrating a random back-ff operation according to a degree of congestion in D2D corresponding to an embodiment of the present invention.

11 is a flowchart of an embodiment for explaining a method of operating a transmitting terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

FIG. 12 is a flowchart of an exemplary embodiment for describing a process of mapping D2D control information illustrated in FIG. 11.

FIG. 13 is a flowchart of another embodiment for explaining a process of mapping D2D control information illustrated in FIG. 11.

14 is a block diagram illustrating an embodiment of an operation apparatus of a transmitting terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

FIG. 15 is a block diagram of an exemplary embodiment for describing the mapping processor illustrated in FIG. 14.

FIG. 16 is a block diagram of another embodiment for describing the mapping processor illustrated in FIG. 14.

17 is a flowchart of an embodiment for explaining a method of operating a reception terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

18 is a block diagram illustrating an embodiment of an operation apparatus of a receiving terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

19 is a flowchart of an embodiment for explaining a method of operating a transmitting terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

20 is a block diagram illustrating an embodiment of an operation apparatus of a transmitting terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

21 is a flowchart of an embodiment for explaining a method of operating a reception terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

FIG. 22 is a block diagram illustrating an embodiment of an operation apparatus of a receiving terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

23 is a flowchart of another embodiment for explaining a method of operating a transmitting terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

24 is a flowchart of an exemplary embodiment for explaining a process of determining transmission timing according to the congestion class illustrated in FIG. 23.

25 is a block diagram of another embodiment for explaining an operation apparatus of a transmitting terminal through resource allocation of D2D communication in a wireless communication system according to the present invention.

FIG. 26 is a block diagram of an exemplary embodiment for describing the transmission timing controller illustrated in FIG. 25.

1 to 26 used in the present patent specification to explain the principles of the present invention are for illustration only and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any wireless communication system in which it is appropriately arranged.

Description of control information, control channel, and resource allocation necessary for describing the contents of the present invention will be described first.

l. Control Information

In cellular communication, a base station transmits control information through various downlinks to a terminal through a downlink to a base station. Control information transmitted by the base station through the downlink to the terminal is referred to as Downlink Control Information (DCI), and control information transmitted by the terminal through the uplink to the base station is referred to as Uplink Control Information (UCI). DCI and UCI have various formats and control information according to the purpose of control, respectively.

(1) Summary of DCI's various formats and important control information:

1) DCI format 0: PUSCH scheduling information

2) DCI format 1: PDSCH (Physical Downlink Shared CHannel) scheduling information

3) DCI format 1A: PDSCH compact scheduling information

4) DCI format 1B: DCI format 1A + precoding information

5) DCI format 1C: PDSCH very compact scheduling + MCCH (Multicast Control CHannel) information

6) DCI format 1D: DCI format 1B + power offset information (Multi-User MIMO: for MU-MIMO)

7) DCI format 2: PDSCH scheduling (for closed-loop MIMO) information

8) DCI format 2A: PDSCH scheduling (for open-loop MIMO) information

9) DCI format 2B: PDSCH scheduling (beamforming) using DM-RS

10) DCI format 2C: PDSCH scheduling (spatial multiplexing) information using DM-RS

11) DCI format 3: 1-bit PUCCH, PUSCH TPC (Transmit Power Control) command information

12) DCI format 3A: 2-bit PUCCH, PUSCH TPC (Transmit Power Control) command information

13) DCI format 4: PUSCH scheduling (multi-antenna port transmission mode)

(2) Summary of various formats and important control information of UCI

1) UCI format 1: Scheduling Request (SR)

2) UCI format 1a: 1-bit HARQ ACK / NACK with or without SR

3) UCI format 1b: 2-bit HARQ ACK / NACK with or without SR

4) UCI format 2: CQI (Channel Quality Information)

5) UCI format 2a: CQI + 1-bit HARQ ACK / NACK

6) UCI format 2b: CQI + 2-bit HARQ ACK / NACK

2. Control channel

In order to transmit various kinds of control information, LTE uses various methods and can be classified into two types.

1) Send control information through independent physical control channel

2) Control information is multiplexed with data information to transmit control information through the data channel

LTE defines various physical control channels. The above control information is transmitted through PDCCH (Physical Downlink Control CHannel) and PUCCH (Physical Uplink Control CHannel). For example, the DCI is transmitted from the base station to the terminal through the downlink PDCCH, and is located in 1 to 3 OFDM symbols of every subframe. On the other hand, the UCI is transmitted to the base station through the PUCCH of the uplink to the base station, and is located in the Resource Block (s) of the frequency axis located at both ends of every subframe.

On the other hand, when the terminal is allocated a PUSCH resource for data transmission in the uplink, the corresponding terminal may need to transmit control information in the uplink. In this case, rather than simultaneously using the PUSCH and the PUCCH, the corresponding UE may multiplex uplink control information on the allocated PUSCH and transmit the same to the base station.

3. Resource Allocation

The resource allocation agent in the cellular system is the base station. That is, the base station allocates resources to the terminal according to various scheduling conditions (for example, fairness, etc.) based on channel information with all terminals located in the cell managed by the base station. For example, a terminal having an uplink resource allocated from the base station reports its buffer status to the base station. At this time, the information for the Buffer Status Report (BSR) is transmitted through the MAC control element of the PUSCH. If the terminal does not have resources allocated for reporting the buffer status, the UE sends a scheduling request (SR) to the base station. At this time, since the scheduling request is made through the PUCCH, only terminals capable of using the PUCCH at the time of requesting scheduling to the base station may perform a status report (SR) (that is, the terminal assigned the PUCCH). In the case of a terminal that has not been allocated a PUCCH to transmit an SR to a base station, resources for buffer status reporting are obtained through a random access process. In addition, the terminal reports the downlink channel measurement result to the base station periodically or by a command of the base station through the PUCCH (eg, UCI formats 4, 5, 6). The base station informs the terminal of the resource information (eg, resource size, MCS: modulation and coding scheme) to be received by the terminal on the basis of the PDCCH. The UE may obtain control information by decoding the PDCCH, and may decode its own data transmitted in downlink through the PDSCH based on the PDCCH.

Meanwhile, for uplink channel measurement, the base station may periodically or aperiodically request a SRS (Sounding Reference Signal) transmission from the UE. The terminal transmits the SRS to the base station according to the command of the base station, and the base station may obtain the uplink channel state of each terminal through the received SRS. The base station allocates an uplink resource that can be used by each terminal based on the uplink channel state obtained by the base station and BSR information transmitted by the terminal through the PUSCH. The uplink resource allocation information is transmitted to the terminal through the PDCCH using DCI (eg, DCI format 0, DCI format 4).

The present invention defines the control information and the control channel as follows for the design and content of the control information for D2D communication, the design of the control channel for transmitting the control information. Hereinafter, the contents of the present invention will be described based on the above-described contents related to control information, control channel, and resource allocation.

1. Content and size of control information

1) common cellular system

D2D communication is performed through the uplink PUSCH. Therefore, DCI format 0 or DCI format 4 which is information related to scheduling of PUSCH among DCIs used in the existing LTE cellular system may be a candidate group of control information for D2D communication. Since the antenna configuration for the D2D communication is assumed to be the transmit antenna 1 and the receive antenna 2, DCI format 0 is used as control information for D2D communication rather than DCI format 4 supporting multi-antenna ports. It is expected to be suitable. However, since there may be D2D communication using multiple antennas in Rel-13 or Rel-14, using DCI format 4 as control information for D2D communication cannot be excluded. The control information included in DCI format 0 and DCI format 4 is described in more detail as follows.

① DCI format 0

Carrier indicator (0 or 3 bits)

-Flag for DCI format 0 / DCI format 1A differentiation (1 bit)

Frequency hopping flag for PUSCH (1 bit)

Resource block assignment

bits)

here

Denotes the number of RBs (Resource Blocks) configuring the UL subframe. If we assume a bandwidth of 10 [MHz],

Since = 50, a total of 11 bits are needed.

MCS and redundancy version (5 bits)

New data indicator (1 bit)

Cyclic shift for DM-RS and OCC index (3 bits)

CSI request (1 or 2 bits)

SRS request (0 or 1 bit)

Resource allocation type (1 bit, only present if)

② DCI format 4

Carrier indicator (0 or 3 bits)

Resource block assignment

bits)

TPC command for PUCCH (2 bits)

MCS per transport block (5 × 2 = 10 bits)

Redundancy version per transport block (2 × 2 = 4 bits)

New data indicator per transport block (1 × 2 = 2 bits)

Cyclic shift for DM-RS and OCC index (3 bits)

SRS request (0 or 1 bit)

Resource allocation type (1 bit, only present if)

The control information constituting DCI format 4 and DCI format 0 is almost similar. However, since DCI format 4 supports multi antennas, MCS, redundancy version (RV), and new data indicator (NDI) information are required for each transport block. In LTE, multi-antennas can transmit up to two transport blocks, so in DCI format 4, such control information is doubled compared to DCI format 0.

2) D2D communication of the present invention

A general cellular system uses PUSCH hopping to obtain frequency diversity in uplink PUSCH transmission, and there are two PUSCH hoppings of type 1 and type 2. Type 2 PUSCH hopping has a cell-specific hopping pattern and hopping is performed in sub-band units. 1 bit hopping flag information transmitted through DCI format 0 corresponds to Type 1, and slot hopping is applied. That is, if PUSCH hopping flag = 0 in DCI format 0, it means that there are no hoppings in two slots constituting one PUSCH subframe. Since the present invention considers a separate pre-defined time hopping pattern for D2D communication, the 1 bit PUSCH hopping flag may be information that is no longer needed.

Meanwhile, since there is no feedback in D2D communication, feedback information such as a TPC command for PUCCH, an SRS request, or a CSI request may no longer be required in the D2D. In addition, since control information (CI) for D2D will use only one format, a flag bit for identifying format 0 and format 1 may not be needed. Carrier indicator may not be suitable as control information for D2D because it is information required for carrier aggregation. Finally, since D2D transmits / receives through an uplink subframe, there may be no distinction between UL and DL. Therefore, 1 bit information for resource allocation type may not be necessary in D2D. Therefore, the summary is as follows.

① D2D CI format A

Resource block assignment

bits)

here

Since = 50, a total of 11 bits are required.

MCS (5 bits or 10 bits)

Redundancy version (1 bit or 4 bits)

New data indicator (1 bit or 2 bits)

Cyclic shift for DM-RS and OCC index (3 bits)

Therefore, assuming a bandwidth of 10 [MHz], the control information for D2D is 11 + 5 + 1 + 1 + 3 = 21 bits (for DCI format 0) or 11 + 10 + 4 + 2 + 3 = 30 bits (for DCI format 4) is required.

However, if the amount of resources that can be used for D2D communication is fixed to each terminal in D2D in the same manner, 11 bits of control information required for resource block assignment may be reduced. In addition, in the case of D2D communication, since there is no feedback, link adaptation such as adaptive modulation and coding or power control may be difficult. In addition, since D2D communication is not aimed at improving bandwidth efficiency or throughput, but is aimed at link reliability, it may be desirable to use a fixed MCS using a low modulation rate and a low coding rate. Therefore, 5 bits or 10 bits information indicating the MCS information may not be needed. In the existing cellular communication, redundancy version (RV) and new data indicator (NDI) are used in HARQ technique. For example, when performing HARQ Chase Combining (CC), NDI information is needed because the same information is retransmitted. This is to determine whether the terminal should perform combining because it is data to perform combining or new data. However, when performing HARQ Incremental Redundancy (IR), since the same information is not retransmitted, RV information indicating the starting point of the circular buffer is needed. The receiving end may perform IR even when information different from the initial transmission is received using the RV information transmitted by the transmitting end. In D2D communication, there seems to be no need for control information such as RV or NDI because there is no feedback. However, since the D2D communication needs to perform reliable transmission, the transmitting end should perform repeated transmission. In other words, in case of HARQ, the transmitter performs transmission-> CRC check at the receiving end and then detects errors-> transmits NACK from the receiving end to the transmitting end-> retransmits at the transmitting end. However, in D2D communication, the transmitting end performs repetitive transmission. In this case, information on the number of repetitions and whether to repeatedly transmit in the form of IR or CC may be necessary. IR can achieve higher coding gain than CC, but it is well known to increase the complexity of the receiver. In addition, the coding gain of IR has been known to increase with the use of a high MCS. Since D2D communication will use a low MCS (e.g. QPSK 1/12), even if CC-type repeated transmission is performed, it is expected that there will be no significant difference in performance compared to IR-type repeated transmission. It is expected to be reduced. Therefore, 1 bit (for DCI format 0) or 2 bits (for DCI format 4) control information for NDI may be needed. Finally, when using the cyclic shift value previously defined in the D2D communication, the control information of 3 bits is no longer needed. Therefore, information necessary for D2D can be reduced to 1 bit as below.

② D2D CI format B

New data indicator (1 bit or 2 bits)

2. Control channel

1) common cellular system

In the case of an independent physical control channel PDCCH, a 16-bit CRC masked by a UE ID (C-RNTI) is added to DCI information of each UE generated by an eNB in an existing cellular system, and a rate 1/3 tailbiting convolution code is added. After encoding, the signal is multiplexed with DCI information of other UEs through a rate matching process. The multiplexed multiple DCI information performs cell-specific and subframe specific scrambling and is symbolized through QPSK modulation. The symbolized DCI information performs interleaving and is mapped to OFDM symbols of the PDCCH through a cell-specific cyclic shift pattern.

In the case of the independent physical control channel PUCCH, the terminal transmits various feedback information to the base station through the PUCCH. Since PUCCH cannot be the subject of comparison of the present invention, detailed description thereof will be omitted.

When the control information is multiplexed with the data information and transmitted, when the terminal has data to be transmitted on the PUSCH, the control information may be transmitted on the PUSCH without transmitting on the PUCCH. That is, after data and control information pass through different coding blocks, rate matching, and modulators, data symbols and control information symbols are multiplexed through time division multiplexing (TDM). The TDM data symbol and the control information symbol constitute an SC-FDM symbol through the DFT and the IFFT.

2) D2D communication of the present invention

When the size of control information for D2D communication is D2D CI format A, a structure for transmitting uplink control information through a PDCCH structure and a PUSCH may be taken. However, in the case of CI format B, it may be transmitted through a structure for transmitting uplink control information through a PUSCH or through a DM-RS.

① Transmit D2D CI format A through independent physical control channel PDCCH

The difference from the existing cellular communication is that D2D communication is performed by groupcast or broadcast method, so that 16-bit CRC added to the control information cannot be masked with UE-ID (C-RNTI). Therefore, masking is performed by newly defined group-RNTI or broadcast-RNTI. On the other hand, instead of cell-specific scrambling, group-specific scrambling should be used. So the scrambling sequence generator

Should be initialized to At this time

A group of exemplifies a firefighter group, a police officer group, and the like, and each group may use a group-specific predefined ID.

② Multiplex D2D CI format A / B with data information (uplink control information is transmitted by PUSCH)

Follow the same procedure as the existing cellular method. At this time, the control information is mapped to the symbols nearest to the DM-RS of the PUSCH.

③ Send D2D CI format B to DM-RS

In the existing cellular communication, the type and size of control information vary, so that information cannot be loaded on the DM-RS. However, in the case of D2D CI format B, since it is 1 bit information, it may be possible to transmit control information through the DM-RS. First, let's take a look at the cyclic shift and Orthogonal Complementary Code (OCC) information used in the existing cellular communication. A sequence currently mapped to uplink DM-RS of LTE will be described with reference to Equations 1 to 4 below.

Equation 1

Here, the meaning of each parameter is as follows.

-

: Number of layers used for transmission (υ: number of antenna ports)

m = 0, 1

-

(

: number of subcarriers constituting the reference signal)

-

: orthogonal sequence

-

: base sequence

u: sequence group number (0 ~ 29)

v: base sequence number

-

: cyclic shift in a slot n _s where

At this time

Is the same as Equation 2 below.

Equation 2

here

Is transmitted to the terminal through a higher layer,

It is a cyclic shift value included in this DCI. Meanwhile

Is as shown in Equation 3 below.

Equation 3

At this time

Is the number of uplink symbols and c (i) represents the pseudo-random sequence. c (i) is initialized using the value of Equation 4 below at the beginning of each radio frame.

Equation 4

At this time

Means the sequence shift pattern of the PUSCH.

to be.

ego

to be.

Means cell ID

Is configured via a higher layer.

In D2D communication, overhead can be reduced by using cyclic shift and OCC values defined in advance. Therefore, all parameters that are changed through the higher layer in Equations 1 to 4 must use fixed values. E.g,

Etc. In addition, in conventional cellular communication, DCI format 0 is used for PUSCH.

Wow

The value of was sent. In D2D these values must be fixed. Meanwhile, the equation 4

silver

Must be defined as In order to transmit 1 bit information of new data indicator to DM-RS, two predefined parameter values can be used.

The above values are one example, and any two fixed values may be used. Since the receiving end may not know which of the two parameters the DM-RS is to be transmitted, the final value should be determined after detecting in all cases.

3. Resource allocation

1) General Distributed Resource Allocation

The distributed resource allocation operation based on the existing energy sensing is as follows. First, signals are received during a predefined sensing period. Thereafter, energy levels of all resource blocks (RBs) within the received sensing interval are measured. The RB (s) having the lowest energy level is then selected to transmit data.

Through this procedure, resources for D2D communication can be spatially reused. However, this distributed-based greedy approach has a disadvantage in that it is vulnerable to a collision problem or congestion problem caused by several terminals simultaneously selecting the same resource.

To overcome this disadvantage, X [%] minimum energy rule or blank RB has been considered. The X [%] minimum energy rule does not select the lowest energy RB (s) when the UE selects RB (s) to transmit data, but sorts the energy levels to lower X [%] (eg , RB (s) having an energy level of 5 [%]). This method has the advantage of randomizing collision or congestion, but it is not a solution when the traffic is increased or the load is heavy.

On the other hand, the blank RB is to stop the transmission and receive in the RB it transmits. The assumption here is that the same data transfer is repeated. That is, if a TX repeatedly transmitting data stops transmitting for a predetermined time and receives the data, it may be determined whether or not another user performs data transmission in the RB used by the TX. If there is no data transmission of another user, the user performs data transmission again. Otherwise, if there is another user's data transmission, the user gives up the data transmission from the RB selected by the user and selects another RB again to perform data transmission. The Blank RB method has a disadvantage of losing its transmission opportunity.

2) Distributed resource allocation in the present invention

In the present invention, distributed resource allocation is also operated based on energy sensing and has the following procedure.

First, signals are received during a predefined sensing period. Thereafter, energy levels of all resource blocks (RBs) within the received sensing interval are measured. Then, the transmission timing is adjusted based on the predefined congestion level.

That is, instead of transmitting data in the next section after energy sensing, the data transmission section is changed according to the congestion level determined by the terminal itself. Congestion level is 2 levels of high / low, 3 levels of high / medium / low, or Level 1, Level 2, Level 3, Level 4,... It can be defined as four or more steps. For example, in the case of step 2: If the number of RBs with energy levels below the predefined threshold is X or more, or if the number of RBs with energy levels above the predefined threshold is X or below, the congestion level is determined to be low. (Conversely, the congestion level is high). In addition, when the number of RBs having energy levels below the predefined threshold is above Y [%] of the total RBs, or when the number of RBs with energy levels above the predefined threshold is below Y% of the total RBs, the congestion level is low. (Conversely, you can judge that the level of congestion is high). Similarly, congestion levels can be defined in three, four, or more steps. At this time, the transmission timing corresponding to each congestion level is a value that must be predefined in advance.

Detailed description of the present invention will be described below with reference to the accompanying drawings.

1 is an example of a structure of a PUCCH control channel to which the present invention is compared. Assuming that there are N resource blocks (RBs) on the frequency axis within a given bandwidth, the PUCCH occupies N _PUCCH RBs at both ends of the frequency band. The remaining RBs are used for transmission of the (N _PUSCH ) PUSCH. In this case, the RB configures an L subcarrier on the frequency axis and an M symbol (SC-FDM symbol) on the time axis.

When designing a control channel for D2D communication, the PUCCH control channel structure of the existing LTE system may be considered. However, simultaneous transmission of PUCCH and PUSCH is not possible in order for a D2D transmitter to transmit data in D2D communication to maintain the characteristics of a single carrier. Therefore, the PUCCH structure may be undesirable as a control channel for D2D communication.

2 is an example of a structure of a PDCCH control channel to which the present invention is compared. The PDCCH occupies N _PDCCH symbols (OFDM symbols) of M symbols on a time axis within one subframe and uses the full bandwidth on the frequency axis.

As a control channel for D2D communication, the PDCCH control channel structure of the existing LTE system may be considered. A base station is the only transmitter that transmits control information in downlink in an existing LTE system. In addition, the base station is the only receiver to receive the control information transmitted in the uplink in the LTE system. However, in D2D communication, a plurality of transmitters may transmit control information and a plurality of receivers may receive control information. Therefore, multiplexing on control channels transmitted by each D2D transmitter should be considered. When considering distributed resource allocation in D2D communication, multiplexing of control channels may not be easy because coordinator does not exist separately. In addition, when the D2D CI format B is selected as the D2D control information, bringing a separate physical control channel structure may cause a lot of system overhead.

Figure 3 shows the physical processing of the PDCCH to be compared of the present invention. 16-bit CRC masked with UE-ID (or C-RNTI) is added to the CI information generated from the upper layer. For example, assuming that the CI information is X bits, X + 16 bits are generated. CI information for each UE is encoded using a tailbiting convolution code having a coding rate 1/3, and multiplexed through rate matching. E.g,

Assumes that after indicating the rate matching, indicates a bits string transmitted to the PDCCH (i) (or UE (i)) in one subframe (ie

To send). The number of PDCCHs that can be transmitted in one subframe

In this case, the following bits columns are generated after multiplexing.

The generated bits columns are scrambled through a cell-specific scramble sequence to randomize the interference of the inter-cell control channel. In particular, at the start of each subframe, the scramble sequence generator is initialized with the value of Equation 5 below.

Equation 5

The scrambled bits columns are mapped to resource elements through interleaving and cell-specific cyclic shifts after QPSK modulation.

4 illustrates an example of piggybacking control information on a PUSCH, which is a comparison target of the present invention. In case of uplink PUSCH transmission (ie, when resources are allocated for PUSCH transmission) in LTE / LTE-A, CQI (channel quality information), PMI (precode matrix index), RI (rank indicator), HARQ Control information such as ACK may be fed back to the base station through a data channel (PUSCH: physical uplink shared channel). Each control information is divided into data information (UL-SCH) and Time Division Multiplexing (TDM) to enter the input of the SC-FDM.

FIG. 5 is a reference diagram illustrating physical processing for format A type of D2D link control information (CI) over a PDCCH corresponding to an embodiment of the present invention. 16-bit CRC masked with Group-ID (or Group-RNTI) and Broadcast-ID (or Broadcast-RNTI) is added to the D2D CI information generated from the upper layer. Group-ID is used for groupcast communication and Broadcast-ID is used for broadcast communication. CI information is encoded using a tailbiting convolution code having a coding rate of 1/3, and scrambled through a group-specific scramble sequence to randomize interference of control channels between different groups through rate matching. In particular, at the start of each subframe, the scramble sequence generator is initialized with the value of Equation 6 below.

Equation 6

The scrambled bits columns are mapped to resource elements through interleaving and group-specific cyclic shifts after QPSK modulation.

FIG. 6 is a reference diagram illustrating piggyback processing for formats A and B of D2D control information (CI) through PUSCH according to an embodiment of the present invention. That is, FIG. 6 illustrates an example of piggybacking D2D CI format A or D2D CI format B with a PUSCH. D2D CI format A or D2D CI format B is time division multiplexed (TDM) with data information (UL-SCH) and enters the input of SC-FDM.

FIG. 7 is a reference diagram illustrating mapping of format A type of D2D control information (CI) of FIG. 6 to PUSCH. That is, FIG. 7 is an example in which the TDM-D2D control information and data information generated in FIG. 6 are mapped to the PUSCH. To increase the reception reliability of the D2D control information, it is mapped to the left or right side of the DM-RS. FIG. 7A illustrates an example of using a long CP and FIG. 7B illustrates an example of using a long CP.

8A is a reference diagram illustrating a resource structure for resource allocation according to an embodiment of the present invention. The bandwidth of the frequency axis is composed of L resource pools (RP), each RP is used by a predefined group, and the basic unit of the size of the RP is N SC-FDM symbols on the time axis and M subcarriers on the frequency axis. RB pair with (subcarrier). When using normal CP, N = 14, M = 12, and when using long CP, N = 12, M = 12. The size of the RP may vary depending on the number of groups and the bandwidth. For example, assuming B-RB for bandwidth, and the predefined number of groups is G, the size of each RP becomes B / G RBs on the frequency axis. That is, the size of the RB constituting each RP is characterized by the same. However, since information on the RP that each group can use may be predefined, the size of the RB in the RP that each group can use may be different.

In addition, each RP has a predefined time shift pattern. For example, during the first K TTI period and the next K TTI period, the resource block of RP1 is shifted once on the time axis and the resource block of RP2 is shifted twice on the time axis. The purpose of this shift is to solve the half-duplex problem. That is, when A1 transmits from RP1 and B1 transmits from RP2 during the K TTI period, A1 and B1 cannot receive each other's signals. Therefore, when different shifts are performed on the time axis in the next K TTI interval, signals may be received from each other. To this end, each D2D transmitter repeatedly transmits its own data N times. Repeated transmission of such data should be transmitted with New Data Indicator (NDI) or Redundancy Version (RV) control information at the transmitter, respectively, so that the receiver can perform chase combining (CC) or incremental redundancy (IR). In this example, a shift pattern shifting only one by one in the time axis between adjacent RPs is assumed, but various shift patterns may exist.

If not a groupcast, a transmitter which intends to perform broadcast communication may transmit control information and data information generated through a broadcast ID instead of a group ID in its RP. However, this method has a disadvantage that the receiving end should always attempt to decode using two IDs, group ID and broadcast ID, and decode all resources. Therefore, in the example of FIG. 8, it is necessary to ensure that a specific RP (s) can be used for broadcast purposes. For example, RP _L can be used only by a transmitter that wants to broadcast, and a terminal performing groupcast communication should always monitor its RP and RP _L.

8B is a reference diagram illustrating a resource structure for resource allocation according to another embodiment of the present invention. The difference from FIG. 8A is that the RP for each group is divided on the time axis. That is, RP1 for group 1 lasts for N1 TTI, and then RP2 for group 2 for another N2 TTI. At this time, N1 and N2 may be the same or different operations.

On the other hand, the following operation is possible to reduce the power consumption of the receiving end. In each RP, the receiving end performs decoding by receiving a signal during the first K TTI period, and then switches to the idle mode during the N-K TTI if it is not related to its group. This requires the assumption that the synchronization is exactly the same between all group members and that the system frame number / frame number is known. It may be assumed that synchronization has been performed between terminals through a separate synchronization channel, and system frame number / frame number may be assumed that all terminals have received through a channel for transmitting separate system information. That is, the transmitting terminal should transmit the MIB like the MIB (Master Information Block) that the base station broadcasts to the terminals existing in the cell it manages.

If the receiving end detects a signal from the first K TTIs and then detects information related to the group to which it belongs or information related to the group to which it should communicate, but not to the group to which it belongs, N does not switch to Idle state. -Receive corresponding data during K TTIs.

9 is a reference diagram illustrating a random back-ff operation in WiFi to which the present invention is compared. In WiFi, a contention window size (eg, 8 or 16) having a default size is operated, and when a NACK is received from the receiver, the contention window size is increased (32, 64, 128,...).

FIG. 10 is a reference diagram illustrating a random back-ff operation according to a degree of congestion in D2D corresponding to an embodiment of the present invention. That is, FIG. 10 shows a table for backoff to prevent congestion in D2D. In FIG. 8, the D2D UE that wants to transmit in the RP of each group scans the energy level during the transmission time interval (T T = 1 ms) and selects the RB having the lowest energy level, and then selects the next TTI (ie, K). + 1 TTI). For example, when the RB having the lowest energy level measured during K TTI at RP1 is A1, the UE transmits data to a resource corresponding to the position of A1 at the next K TTI. It is assumed that the UE belonging to each group knows the RP used by the group and the time shift pattern in the corresponding RP in advance. However, if the next TTI is transmitted after the scan during the K TTI, there is a need for a method of preventing the transmission because the probability of transmitting the same resource between terminals increases. Backoff in WiFi may be a similar scheme, but as shown in FIG. 9, the contention window size increases when WiFi is NACKed. Since D2D communication does not have a separate feedback channel, the transmitter should determine its state and adjust the contention window size accordingly.

Therefore, in the present invention, the data transmission section is changed according to the congestion level determined by the terminal itself, rather than transmitting data in the next section after energy sensing. Congestion level is 2 levels of high / low, 3 levels of high / medium / low, or Level 1, Level 2, Level 3, Level 4,... It can be defined as four or more steps. For example, in the case of step 2: If the number of RBs with energy levels below the predefined threshold is X or more, or if the number of RBs with energy levels above the predefined threshold is X or below, the congestion level is determined to be low. (Or vice versa, the congestion level is high). In addition, when the number of RBs having energy levels below the predefined threshold is above Y [%] of the total RBs, or when the number of RBs with energy levels above the predefined threshold is below Y% of the total RBs, the congestion level is low. It can be determined (or vice versa, the level of congestion is high). Similarly, congestion levels can be defined in three, four, or more steps. At this time, the transmission timing corresponding to each congestion level is a value that should be predefined in advance.

The transmitting terminal maps the D2D control information for the D2D communication to at least one of Physical Downlink Control CHannel (PDCCH), Physical Uplink Shared CHannel (PUSCH), and Demodulation-Reference Signals (DM-RS) (S100).

After step S100, the transmitting terminal transmits the D2D control information mapped to at least one of the PDCCH, the PUSCH, and the DM-RS to a receiving terminal for D2D communication (S102).

FIG. 12 is a flowchart of an exemplary embodiment for describing a process of mapping D2D control information illustrated in FIG. 11. 12 illustrates a mapping process when the D2D control information is mapped to a symbol of the PDCCH. In this case, the D2D control information mapped to the symbol of the PDCCH includes resource block assignment information, Modulation and Coding Scheme (MCS) information, redundancy version information, new data identifier information, and DM information. Cyclic shift information and Orthogonal Complementary Code (OCC) index information for a demodulation-reference signal (RS) may be included.

First, the transmitting terminal adds at least one of the groupcast ID and the broadcast ID for the group defining the range of the D2D communication to the D2D control information (S200). When the transmitting terminal adds a groupcast ID or broadcast ID to the D2D control information, the transmitting terminal adds masking of the groupcast ID or broadcast ID to a cyclic redundancy code (CRC) to the D2D control information. Since D2D communication is performed by groupcast or broadcast method, 16-bit CRC masked by newly defined group cast ID (or Group-RNTI) and broadcast ID (or Broadcast-RNTI) in 16-bit CRC added to the control information. Is added to the D2D control information.

After step S200, the transmitting terminal convolutionally codes the D2D control information to which the groupcast ID or the broadcast ID is added (S202). The D2D control information may be encoded using a tailbiting convolution code having a coding rate 1/3.

After step S202, the transmitting terminal matches the transmission rate for the convolution coded D2D control information (S204).

After step S204, the transmitting terminal scrambling the D2D control information matched with the transmission rate using the groupcast ID or the broadcast ID (S206). In the present invention, group specific scrambling should be used. In order to randomize the interference of control channels between different groups with respect to the rate-matched D2D control information, scrambling is performed through a group-specific scramble sequence. In particular, it is initialized to the value of Equation 6 at the start of each subframe. Each group uses a group-specific predefined ID.

After step S206, the transmitting terminal modulates the scrambled D2D control information (S208). The D2D control information may perform quadrature phase shift keying (QPSK) modulation as an example of a modulation scheme.

After step S208, the transmitting terminal interleaves the modulated D2D control information (S210).

After step S210, the transmitting terminal performs a group-specific cyclic shift processing on the interleaved D2D control information (S212). It is mapped to a resource element via a group specific cyclic shift.

FIG. 13 is a flowchart of another embodiment for explaining a process of mapping D2D control information illustrated in FIG. 11. FIG. 13 illustrates a mapping process when the D2D control information is mapped to a symbol of the PUSCH. In this case, the D2D control information mapped to the symbol of the PSCCH includes resource block assignment information, Modulation and Coding Scheme (MCS) information, redundancy version information, new data identifier information, and DM information. Cyclic shift information and Orthogonal Complementary Code (OCC) index information for a demodulation-reference signal (RS) may be included. In addition, the D2D control information mapped to the symbol of the PSCCH may include only new data indicator information corresponding to 1 bit.

First, when the transmitting terminal maps the D2D control information to a symbol of the PUSCH, convolutional coding is performed on the D2D control information (S300). After the step S300, the transmitting terminal matches the transmission rate for the convolutionally coded D2D control information (S302). After step S302, the transmitting terminal modulates the D2D control information matched with the transmission rate (S304).

After step S304, the transmitting terminal multiplexes the modulated D2D control information with the modulated data information of the PUSCH (S306). When multiplexing the D2D control information with the data information, the transmitting terminal maps to symbols nearest to the demodulation-reference signals (DM-RSs) of the PUSCH. The mapping of the D2D control information to the symbols of the PUSCH is to perform piggyback processing on the format A and B types of the D2D control information (CI) through the PUSCH in FIG. Therefore, format A or format B of the D2D control information is time-division-divided (Time Division Multiplexing (TDM)) with data information (UL-SCH) and enters the input of the SC-FDM. At this time, in order to increase the reception reliability of the D2D control information, it is mapped to the left or right side of the DM-RS.

Meanwhile, as another embodiment of mapping the D2D control information, the D2D control information may be directly mapped to the demodulation-reference signal (DM-RS). At this time, the transmitting terminal maps the new data indicator information as the D2D control information mapped to the DM-RS.

In the existing cellular communication, since the type and size of control information vary, information cannot be loaded on the DM-RS. However, in the case of format B of the D2D control information, only new data indicator information corresponding to 1 bit information is available. Since it is transmitted, it is possible to transmit the D2D control information through the DM-RS.

In order to transmit 1 bit information of new data indicator corresponding to D2D control information to DM-RS, two predefined parameter values may be used.

The above values are one example, and any two fixed values may be used. Since the receiving end may not know which of the two parameters the DM-RS is to be transmitted, the detection is performed in all cases and then the final value is determined.

FIG. 14 is a block diagram of an exemplary embodiment for describing an operation apparatus 400 of a transmitting terminal through resource allocation of D2D communication in a wireless communication system, including a mapping processor 410 and a transmitter 420. do.

The mapping processor 410 maps the D2D control information for D2D communication to at least one of Physical Downlink Control CHannel (PDCCH), Physical Uplink Shared CHannel (PUSCH), and Demodulation-Reference Signals (DM-RS). It is transmitted to the transmitter 420.

The transmitter 420 transmits the D2D control information mapped to at least one of the PDCCH, the PUSCH, and the DM-RS to a receiving terminal. To this end, the transmitter 420 includes a wireless communication module for interfacing wireless communication with a receiving terminal.

FIG. 15 is a block diagram illustrating an example of the mapping processing unit 410 illustrated in FIG. 14, and is a block diagram 410A when the D2D control information is mapped to a symbol of the PDCCH. To this end, the mapping processor 410 is a group information addition module 500, the first convolutional coding module 510, the first rate matching module 520, the scrambling module 530, the first modulation module 540, interleaving Module 550 and cyclic shift module 560.

When the group information adding module 500 maps the D2D control information to a symbol of the PDCCH, the group information adding module 500 adds a groupcast ID or broadcast ID for the group defining the range of the D2D communication to the D2D control information. The control information added with the groupcast ID or the broadcast ID is transmitted to the first convolutional coding module 510. The group information adding module 500 adds masking of the groupcast ID or the broadcast ID to a cyclic redundancy code (CRC) to the D2D control information.

In this case, the D2D control information mapped to the symbol of the PDCCH includes resource block assignment information, Modulation and Coding Scheme (MCS) information, redundancy version information, new data identifier information, and DM information. Cyclic shift information for the demodulation-reference signal (RS) and orthogonal complementary code (OCC) index information are included.

The first convolutional coding module 510 convolutionally codes the D2D control information added with the groupcast ID and the broadcast ID, and converts the convolutional coded D2D control information to the first rate matching module 520. To pass. The first convolutional coding module 510 may encode the D2D control information by using a tailbiting convolution code having a coding rate 1/3.

The first rate matching module 520 matches the rate for the convolutional coded D2D control information, and transmits the matched rate of the D2D control information to the scrambling module 530.

The scrambling module 530 uses the groupcast ID or the broadcast ID to scramble the D2D control information having a matching rate, and transmits the scrambled D2D control information to the first modulation module 540. . The scrambling module 530 scrambling through the group-specific scramble sequence to randomize the interference of the control channel between different groups for the D2D control information with a matching rate.

The first modulation module 540 modulates the scrambled D2D control information, and transmits the modulated D2D control information to the interleaving module 550. As an example of a modulation scheme, the first modulation module 540 may perform quadrature phase shift keying (QPSK) modulation on the D2D control information.

The interleaving module 550 interleaves the modulated D2D control information and transmits the interleaved D2D control information to the cyclic shift module 560.

The cyclic shift module 560 performs group-specific cyclic shift on the interleaved D2D control information.

FIG. 16 is a block diagram illustrating another example of the mapping processing unit illustrated in FIG. 14, and is a block diagram 410B when the D2D control information is mapped to a symbol of the PUSCH. To this end, the mapping processor 410 includes a second convolutional coding module 600, a second rate matching module 610, a second modulation module 620, and a multiplexing module 630. In this case, the D2D control information mapped to the symbol of the PSCCH includes resource block assignment information, Modulation and Coding Scheme (MCS) information, redundancy version information, new data identifier information, and DM information. Cyclic shift information and Orthogonal Complementary Code (OCC) index information for a demodulation-reference signal (RS) may be included. In addition, the D2D control information mapped to the symbol of the PSCCH may include only new data indicator information corresponding to 1 bit.

When the second convolutional coding module 600 maps the D2D control information to a symbol of the PUSCH, the second convolutional coding module 600 convolutionally codes the D2D control information, and converts the convolutionally coded D2D control information into a second rate matching module. Forward to 610.

The second rate matching module 610 matches the rate for the convolutionally coded D2D control information, and transmits the D2D control information matched with the rate to the second modulation module 620.

The second modulation module 620 modulates the D2D control information with matching data rates, and transmits the modulated D2D control information to the multiplexing module 630.

The multiplexing module 630 multiplexes the modulated D2D control information with the modulated data information of the PUSCH.

The multiplexing module 630 maps the D2D control information to symbols closest to Demodulation-Reference Signals (DM-RS) of the PUSCH. The multiplexing module 630 maps the D2D control information to the left or right side of the DM-RS in order to increase the reception reliability of the D2D control information.

Meanwhile, when mapping the D2D control information to the DM-RS, the mapping processor 410 may map new data indicator information as the D2D control information. In this case, the mapping processor 410 uses a parameter value having a size of 1 bit as the new data identifier information. In the case of format B of the D2D control information, since only new data indicator information corresponding to 1 bit information is transmitted, it is possible to transmit the D2D control information through the DM-RS. Two predefined parameter values may be used to carry and transmit 1 bit information of a new data indicator corresponding to D2D control information to the DM-RS. Since the receiver does not know which of the two parameters the DM-RS is to be transmitted, the detection is performed in all cases and then the final value is determined.

When the D2D control information is mapped and transmitted from at least one of a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), and a demodulation-reference signal (DM-RS) from a transmitting terminal for D2D communication, the D2D control At least one of the PDCCH, the PUSCH, and the DM-RS to which information is mapped is received (S700).

After operation S700, at least one of the received PDCCH, the PUSCH, and the DM-RS is recovered to extract the D2D control information (S702).

When the D2D control information is received mapped to a symbol of the PDCCH, at least one of a groupcast ID and a broadcast ID for a group defining a range of the D2D communication is extracted from the symbol of the PDCCH. In order to extract the D2D control information from the symbol of the PDCCH, the D2D control information is extracted by restoring data in the reverse order of the mapping process of the PDCCH shown in FIG.

In addition, when the D2D control information is received mapped to the symbol of the PUSCH, the D2D control information is demultiplexed and extracted from the modulated data information of the PUSCH. In order to extract the D2D control information from the symbol of the PUSCH, the D2D control information is extracted by restoring data in the reverse order of the mapping process of the PUSCH shown in FIG.

In addition, when the D2D control information is mapped to the DM-RS and received, new data indicator information is extracted as the D2D control information. At this time, new data identifier information of one bit is extracted using two parameter values as the D2D control information. Since the DM-RS including the D2D control information does not know which of the two parameters, the final value is determined after detection in all cases.

18 is a block diagram of an exemplary embodiment for explaining an operation apparatus of a receiving terminal through resource allocation of D2D communication in a wireless communication system, including a receiving unit 810 and a control information extracting unit 820. .

When the D2D control information for the D2D communication is mapped to at least one of Physical Downlink Control CHannel (PDCCH), Physical Uplink Shared CHannel (PUSCH), and Demodulation-Reference Signals (DM-RS), The PDCCH, the PUSCH, or the DM-RS to which the D2D control information is mapped is received from a transmitting terminal. To this end, the receiver 810 includes a wireless communication module for interfacing wireless communication with a transmitting terminal.

The control information extractor 820 extracts the D2D control information by restoring at least one of the received PDCCH, the PUSCH, and the DM-RS.

When the D2D control information is received mapped to the symbol of the PDCCH, the control information extracting unit 820 includes at least one of a groupcast ID and a broadcast ID for the group defining the range of the D2D communication. Extract from symbol. The control information extractor 820 extracts the D2D control information by restoring data in the reverse order of the mapping process of the PDCCH in order to extract the D2D control information from the symbol of the PDCCH.

In addition, the control information extractor 820 demultiplexes the D2D control information from the modulated data information of the PUSCH when the D2D control information is received mapped to the symbol of the PUSCH. The control information extractor 820 extracts the D2D control information by restoring data in the reverse order of the mapping process of the PUSCH in order to extract the D2D control information from the symbol of the PUSCH.

The control information extractor 820 extracts new data indicator information as the D2D control information when the D2D control information is mapped to the DM-RS and received. At this time, the control information extracting unit 820 extracts new data identifier information of one bit as two-dimensional control information using two parameter values. Since the control information extracting unit 820 does not know which of the two parameters, the DM-RS including the D2D control information has any value, the control information extracting unit 820 determines the final value after performing detection in all cases.

A resource structure is set to include at least one resource pool having a plurality of resource blocks based on a predetermined time (S900). As shown in FIG. 8A, the bandwidth of the frequency axis includes L resource pools RP, and each resource pool RP is used by a predefined group. The basic unit of the size of each resource pool is a resource block pair having N SC-FDM symbols on the time axis and M subcarriers on the frequency axis. N = 14, M = 12 when using Normal CP (Cyclic Prefix), N = 12, M = 12 when using long CP. The size of the RP may vary depending on the number of groups and the bandwidth. For example, assuming B-RB for bandwidth and the predefined number of groups is G, the size of each resource pool becomes B / G RBs on the frequency axis. That is, the size of the resource block constituting each resource pool is the same.

In addition, as shown in FIG. 8B, the RP for each group is divided into a time axis. That is, during N1 TTI is set as RP1 for group 1, and as RP2 for group 2 during another N2 TTI.

After operation S900, the resource blocks included in the resource pool are shifted on a time axis every predetermined time to allocate a resource for a signal to be transmitted (S902). The shifting of the resource blocks to the time axis shifts the resource blocks such that the shift interval of the resource pool is different from the shift interval of another resource pool.

Resource pools each have a predefined time shift pattern. For example, as shown in FIG. 8A, the resource block of resource pool 1 (RP1) is shifted once on the time axis during the first K TTI interval (1 TTI = 1 ms) and during the next K TTI interval. Resource blocks of resource pool 2 (RP2) are shifted twice on the time axis. The purpose of this shift is to solve the half-duplex problem. That is, when A1 transmits in resource pool 1 (RP1) and B1 transmits in resource pool 2 (RP2) during the K TTI interval, A1 and B1 cannot receive signals from each other. Therefore, when different shifts are performed on the time axis in the next K TTI interval, signals may be received from each other. To this end, each transmitting terminal repeatedly transmits its D2D data N times. Repeated transmission of such data should be transmitted together with New Data Indicator (NDI) or Redundancy Version (RV) control information at the transmitting terminal so that the receiving terminal can perform chase combining or incremental redundancy (IR). In this example, a shift pattern shifting only one by one in the time axis between adjacent RPs is assumed, but various shift patterns may exist. On the other hand, a transmitting terminal that wants to perform broadcast communication instead of a groupcast may transmit control information and data information generated through a broadcast ID instead of a group ID from its resource pool. When performing broadcast communication, the receiving terminal should always attempt to decode using two IDs, group ID and broadcast ID, and decode all resources. Therefore, in the example of FIG. 8, it is necessary to ensure that a specific resource pool can be used for broadcast purposes. For example, the resource pool L (RPL) can be used only by a transmitter that wants to broadcast, and the receiving terminal that performs groupcast communication always monitors the resource pool L (RPL) that performs broadcast communication with its own resource pool. )do.

On the other hand, when the period in which the predetermined time is summed a certain number of times as a unit period, it may be grouped by the unit period to allocate resources. As shown in FIG. 8B, when N1 TTI or N2 TTI is used as an example of a unit period, if RP for each group is divided into time axes, RP1 for group 1 is allocated during N1 TTI, and then again. RP2 for group 2 is allocated during another N2 TTI. At this time, N1 and N2 may be the same size or may be operated differently.

After the step S902, the signal is transmitted to the receiving terminal by using the allocated resources (S904).

20 is a block diagram of an exemplary embodiment 1000 for explaining an operation apparatus of a transmitting terminal through resource allocation of D2D communication in a wireless communication system according to the present invention. The resource structure setting unit 1010 and the resource allocating unit are shown. 1020 and a transmission interface unit 1030.

The resource structure setting unit 1010 sets a resource structure to include at least one resource pool having a plurality of resource blocks based on a predetermined time. As shown in FIG. 8A, the resource structure setting unit 1010 configures L resource pools RP based on the frequency axis, and defines each resource pool RP to be used by a predefined group. The resource structure setting unit 1010 allows a pair of resource blocks having N SC-FDM symbols on the time axis and M subcarriers on the frequency axis to form a resource pool, and these resource pools Make a resource structure. In addition, as shown in FIG. 8B, the resource structure setting unit 1010 divides the RP for each group by the time axis, sets N1 TTI as RP1 for group 1, and sets group 2 during another N2 TTI. Is set as RP2.

The resource allocator 1020 allocates a resource for a transmission signal by shifting the resource blocks included in the resource pool on a time axis every predetermined time. The shift control unit 1020 shifts the resource blocks such that the shift interval of the resource pool is different from the shift interval of another resource pool.

The resource allocator 1020 has a predefined time shift pattern for each of the resource pools. For example, as shown in FIG. 8A, the resource allocator 1020 may include resource blocks of resource pool 1 (RP1) during the first K TTI interval (1 TTI = 1ms) and during the next K TTI interval. Is shifted once on the time axis, and resource blocks of resource pool 2 (RP2) are shifted twice on the time axis. Accordingly, when different shifts are performed on the time axis in the next K TTI interval, signals of each other may be received. In this example, a shift pattern shifting only one by one in the time axis between adjacent RPs is assumed, but various shift patterns may exist.

In addition, the resource allocator 1020 may allocate a resource by grouping the unit periods in a unit cycle when the predetermined time sums up a predetermined number of times. As shown in FIG. 8B, when N1 TTI or N2 TTI is used as an example of a unit period, if the RP for each group is divided into time axes, RP1 for group 1 is allocated during N1 TTI, and then again. Allocate RP2 for group 2 during another N2 TTI. In this case, the resource allocator 1020 may allocate N1 and N2 to the same size or operate differently.

Accordingly, the transmission interface unit 1030 transmits a signal to the receiving terminal by using the allocated resource.

In the wireless communication system, an operating device of a transmitting terminal through resource allocation of device to device (D2D) communication may include D2D control information for the D2D communication, including physical downlink control channel (PDCCH), physical uplink shared channel (PUSCH), and DM- A mapping processor configured to map at least one of RS (Demodulation-Reference Signals); And a transmitter for transmitting the D2D control information mapped to at least one of the PDCCH, the PUSCH, and the DM-RS to a receiving terminal.

When the mapping processor maps the D2D control information to a symbol of the PDCCH, the mapping processor adds at least one of a groupcast ID and a broadcast ID for the group defining the range of the D2D communication to the D2D control information. The apparatus may further include a group information adding module, and the D2D control information to which the groupcast ID or the broadcast ID is added may be mapped to a symbol of the PDCCH.

The D2D control information includes resource block assignment information, Modulation and Coding Scheme (MCS) information, redundancy version information, new data indicator information, and DM-RS (Demodulation-Reference). One or more of cyclic shift information for a signal and orthogonal complementary code (OCC) index information may be included.

The group information adding module may add masking one of the groupcast ID and the broadcast ID to a cyclic redundancy code (CRC) to the D2D control information.

The mapping processor may include: a first convolutional coding module configured to convolutionally code the D2D control information added with the groupcast ID and the broadcast ID; A first rate matching module for matching a rate for the convolutionally coded D2D control information; A scrambling module for scrambling the D2D control information whose rate is matched using any one of the groupcast ID and the broadcast ID; A first modulation module for modulating the scrambled D2D control information; An interleaving module for interleaving the modulated D2D control information; And a cyclic shift module for group-specific cyclic shift of the interleaved D2D control information.

The mapping processor may include: a second convolutional coding module configured to convolutionally code the D2D control information when the D2D control information is mapped to a symbol of the PUSCH; A second rate matching module for matching a rate for the convolutionally coded D2D control information; A second modulation module for modulating the D2D control information with matching data rates; And a multiplexing module for multiplexing the modulated D2D control information with the modulated data information of the PUSCH.

The multiplexing module may map the D2D control information to symbols nearest to the demodulation-reference signals (DM-RSs) of the PUSCH.

The mapping processor may map new data indicator information as the D2D control information when the D2D control information is mapped to the DM-RS.

The mapping processor may use a parameter value having a size of 1 bit as the new data identifier information.

According to various embodiments of the present disclosure, in a wireless communication system, an operation apparatus of a receiving terminal through resource allocation of device to device (D2D) communication may include: D2D control information for the D2D communication includes physical downlink control channel (PDCCH) and physical uplink shared (PUSCH). A receiver configured to receive at least one of the PDCCH, the PUSCH, and the DM-RS to which the D2D control information is mapped when it is mapped and transmitted to at least one of CHannel) and Demodulation-Reference Signals (DM-RS); And a control information extracting unit configured to extract at least one of the received PDCCH, the PUSCH, and the DM-RS to extract the D2D control information.

The control information extracting unit extracts at least one of a groupcast ID and a broadcast ID for a group defining a range of the D2D communication from the symbols of the PDCCH when the D2D control information is received mapped to the symbols of the PDCCH. can do.

The control information extractor may extract and extract the D2D control information from the modulated data information of the PUSCH when the D2D control information is received mapped to a symbol of the PUSCH.

The control information extracting unit may extract new data indicator information as the D2D control information when the D2D control information is received mapped to the DM-RS.

The control information extracting unit may extract the new data identifier using a parameter value having a size of 1 bit.

According to various embodiments of the present disclosure, an operating device of a transmitting terminal through resource allocation of device to device (D2D) communication in a wireless communication system may include at least one resource pool having a plurality of resource blocks (Resouce Blocks) based on a predetermined time period. A resource structure setting unit for setting a resource structure to include a Resouce Pool; A resource allocator for allocating a resource for a signal to be transmitted by shifting the resource blocks included in the resource pool on a time axis every predetermined time; And a transmission interface unit for transmitting the signal to a receiving terminal by using the allocated resource.

The resource allocator may shift the resource blocks such that the shift interval of the resource pool is different from the shift interval of another resource pool every predetermined time.

The resource allocator may allocate a resource by grouping the unit periods in a unit cycle when the predetermined time sums up a predetermined number of times.

In various embodiments of the present disclosure, an apparatus for operating a receiving terminal through resource allocation of device to device (D2D) communication in a wireless communication system may include: a receiving interface unit that interfaces reception of a signal transmitted from a transmitting terminal; When a resource for a signal is allocated according to a resource structure including at least one resource pool having a plurality of resource blocks based on a predetermined time, the transmitting terminal through the allocated resource A control unit controlling to receive the signal from the computer; And a decoder for decoding the received signal.

The control unit determines whether the signal is information related to its own group when the signal is transmitted through the allocated resource grouped by the unit period, and if the signal corresponds to information related to its own group, the control unit detects the signal. Can be controlled to receive.

The controller may determine whether the signal is information related to its group by using the system frame information when receiving the system frame information indicating information on the allocated resource grouped by the unit period from the transmitting terminal. Can be.

The controller may control to switch to the standby mode when the signal is not information related to its own group when the signal is transmitted through the allocated resource grouped by the unit period.

According to various embodiments of the present disclosure, an apparatus for operating a transmitting terminal through resource allocation of device to device (D2D) communication in a wireless communication system may include: a signal receiving unit configured to receive signals for the D2D communication for a predetermined time; An energy level detector for detecting an energy level of each of the resource blocks corresponding to the signals received during the predetermined time; And a transmission timing controller configured to determine a transmission timing of data for the D2D communication according to a congestion class corresponding to the detected energy levels.

The transmission timing controller includes an energy level comparison module for comparing the energy levels with a predetermined threshold value; A congestion class determining module configured to determine the congestion class according to a result of comparing the energy levels with the predetermined threshold value; And a timing determination module that determines the transmission timing corresponding to the determined congestion class.

The transmission timing controller may increase a transmission window size of the transmission timing as the degree of congestion according to the determined congestion level increases.

A resource for a signal is allocated according to a resource structure including one or more resource pools having a plurality of resource blocks based on a predetermined time, and is a unit in which the predetermined time is summed up a certain number of times. In the case of a period, when the resource is allocated by grouping by the unit period, when a signal is transmitted through the allocated resource grouped by the unit period, it is determined whether the signal is information related to its own group (S1050). . The process of determining whether the signal is information related to its own group includes receiving the system frame information indicating the information about the allocated resource grouped by the unit period from the transmitting terminal and using the system frame information. Determines whether is information related to its own group.

As shown in FIG. 8B, after receiving a signal during the first K TTI period in each RP, decoding may be performed, and when the information is not related to its own group, it may be switched to the idle mode during the N-K TTI. This requires the assumption that the synchronization is exactly the same between all group members and that the system frame number / frame number is known. It may be assumed that synchronization has been performed between terminals through a separate synchronization channel, and system frame number / frame number may be assumed that all terminals have received through a channel for transmitting separate system information. That is, when the transmitting terminal transmits the MIB to the receiving terminal, such as a MIB (Master Information Block) that the base station broadcasts to the terminals existing in the cell that it manages, the receiving terminal uses the system frame number / frame number in each TTIs. It is determined whether the transmitted signal corresponds to information related to its own group.

In step S1050, if the signal corresponds to information associated with its group, the signal transmitted from the transmitting terminal is received through the allocated resource (S1052). As shown in FIG. 8B, after receiving a signal from the first K TTIs, the receiving terminal may detect information related to a group to which it belongs or information related to a group to which it should communicate, although it is not a group to which it belongs. In this case, the corresponding data is received during the NK TTIs without switching to the idle state.

After step S1052, the received signal is decoded (S1054).

Meanwhile, in step S1050, when the signal is transmitted through the allocated resources grouped by the unit period, if the signal is not information related to its own group, the signal is switched to an idle mode (S1056). In order to reduce the power consumption of the receiver, at each RP, the receiver receives a signal during the first K TTI period, performs decoding, and then switches to the idle mode during the N-K TTI if it is not related to its group.

FIG. 22 is a block diagram of an embodiment for explaining an operation apparatus of a receiving terminal through resource allocation of D2D communication in a wireless communication system according to the present invention. The receiving interface unit 1060, the control unit 1070, and the decoder 1080 are shown in FIG. ).

The reception interface unit 1060 interfaces reception of a signal transmitted from a transmission terminal.

When the resource for the signal is allocated according to a resource structure including at least one resource pool having a plurality of resource blocks based on a predetermined time, the controller 1070 may allocate the allocated resource. Through the control to receive the signal from the transmitting terminal.

The allocated resources are allocated by grouping the unit periods when the periods in which the predetermined time is added a predetermined number of times are unit cycles. In this case, when the signal is transmitted through the allocated resource grouped by the unit period, the controller 1070 determines whether the signal is information related to its own group, and the signal corresponds to information related to its own group. Control to receive the signal.

The controller 1070 determines whether the signal is information related to its own group by using the system frame information when receiving system frame information indicating information on the allocated resource grouped by unit period from the transmitting terminal. .

As the base station transmits the MIB to the receiving terminal, such as a MIB (Master Information Block) that the base station broadcasts to the terminals existing in the cell it manages, the control unit 1070 uses a system frame number / frame number in each TTIs It is determined whether the transmitted signal corresponds to information related to its own group. If the signal corresponds to information associated with its group, the controller 1070 controls to receive the signal transmitted from the transmitting terminal through the allocated resource. As shown in FIG. 8B, the controller 1070 detects a signal in the first K TTIs and then displays information related to the group to which it belongs, or information related to the group to which it should communicate, although it is not the group to which it belongs. If it detects it, it does not switch to idle state and receives the data during NK TTIs.

Meanwhile, when the signal is transmitted through the allocated resource grouped by the unit period, the controller 1070 controls to switch to the standby mode if the signal is not information related to its group. In order to reduce the power consumption of the receiver, the controller 1070 receives a signal during the first K TTI interval and decodes the signal at each RP, and then switches to the idle mode during the NK TTI when the information is not related to its group. .

Decoder 1080 decodes the received signal.

In operation S1100, signals for the D2D communication are received for a predetermined time.

After the step S1100, the energy levels of each of the resource blocks corresponding to the signals received during the predetermined time are detected (S1102). For example, in FIG. 8, a transmitting terminal desiring D2D communication in a resource pool of each group detects energy levels of resource blocks belonging to each resource pool for a transmission time interval (1 TTI = 1ms) time.

After operation S1102, the transmission timing of the data for the D2D communication is determined according to the congestion level corresponding to the detected energy levels (S1104).

The energy levels are compared with a predetermined threshold (S1200). For example, in FIG. 8, when energy levels of resource blocks belonging to each resource pool are respectively detected during a transmission time interval (TTI = 1 ms) time, the detected energy levels are compared with a predetermined threshold value. do.

After the step S1200, the congestion level is determined according to the comparison result of the energy levels and the predetermined threshold value (S1202). Congestion rating is 2 levels of high / low, 3 levels of high / medium / low, or Level 1, Level 2, Level 3, Level 4,. It can be set in four or more steps, and the grade can be adjusted as needed. For example, in the second stage in which the congestion class corresponds to (a) of FIG. 10, the number of resource blocks having an energy level below a certain threshold is greater than or equal to X, or the resource blocks having energy levels above a certain threshold. If the number is less than or equal to X, you can determine that the congestion rating is low. However, on the contrary, it can be determined that the congestion rating is high. In addition, when the number of resource blocks having an energy level below a certain threshold is greater than or equal to Y [%] of all resource blocks, or when the number of resource blocks having an energy level above a certain threshold is less than or equal to Y [%] among all resource blocks. It can be determined that the congestion level is low. However, on the contrary, it can be determined that the congestion rating is high. In addition, even when the congestion grade is three or four or more levels, the congestion grade may be determined in the same manner as described above.

After step S1202, the transmission timing corresponding to the determined congestion class is determined (S1204). As an example of determining the transmission timing, as the degree of congestion according to the determined congestion class increases, a transmission window size of the transmission timing is increased. In FIG. 10, the transmission window size is preset according to the congestion class. That is, in the case of the second stage in which the congestion class corresponds to (a) of FIG. 10, when the congestion class is low (No), collisions due to data transmission occur relatively less, thereby reducing the transmission window size. However, when the congestion level is high (Yes), collisions due to data transmission occur relatively frequently, thereby increasing the transmission window size. In addition, even when the congestion level is three or four or more levels, as the degree of congestion increases in the same manner as described above, the transmission window size of the transmission timing is increased.

FIG. 25 is a block diagram of another exemplary embodiment 1300 for explaining an operation apparatus of a transmitting terminal through resource allocation of D2D communication in a wireless communication system according to the present invention, and includes a signal detector 1310 and an energy level detector. 1320 and the transmission timing controller 1330.

The signal detector 1310 receives signals for the D2D communication for a predetermined time and transmits the received signal to the energy level detector 1320.

The energy level detector 1320 detects an energy level of each of the resource blocks corresponding to the signals received during the predetermined time, and transmits the detected result to the transmission timing controller 1330. For example, the energy level detector 1320 detects energy levels of resource blocks belonging to each resource pool for a transmission time interval (KTTI) of 1 TTI = 1ms.

The transmission timing controller 1330 determines a transmission timing of data for the D2D communication according to a congestion class corresponding to the detected energy levels.

FIG. 26 is a block diagram of an exemplary embodiment for explaining the transmission timing controller illustrated in FIG. 25 and includes an energy level comparison module 1400, a congestion class determination module 1410, and a timing determination module 1420.

The energy level comparison module 1400 compares the energy levels with a predetermined threshold value and transmits the result of the comparison to the congestion grade determination module 1410. For example, the energy level comparison module 1400 may detect the energy levels of the resource blocks belonging to each resource pool during a transmission time interval (KTTI) period of 1 TTI. Compare the value with the size.

The congestion grade determination module 1410 determines the congestion grade according to a result of comparing the energy levels with the predetermined threshold value, and transmits the determined result to the timing determination module 1420. The congestion class determination module 1410 may include two levels of high / low, three levels of high / medium / low, or Level 1, Level 2, Level 3, Level 4,. Table information on a congestion class set in at least four levels, and a transmission window size corresponding to the congestion class are stored. Meanwhile, such table information may be stored in a separate storage space.

For example, in the case of the second stage in which the congestion class corresponds to (a) of FIG. 10, the congestion class determination module 1410 may determine that the number of resource blocks having an energy level equal to or lower than a certain threshold is greater than or equal to X If the number of resource blocks having an energy level greater than or equal to X is less than or equal to, the congestion class may be determined to be low, and conversely, the congestion class may be determined to be high. In addition, the congestion class determination module 1410 may determine that the number of resource blocks having an energy level of less than or equal to a predetermined threshold is greater than or equal to Y [%] of the total resource blocks, or the number of resource blocks having an energy level of more than or equal to a predetermined threshold is the total resource block. In the case of Y [%] or less, it may be determined that the congestion grade is low, and vice versa. In addition, even when the congestion grade is three or four or more stages, the congestion grade determination module 1410 may determine the congestion grade in the same manner as described above.

The timing determination module 1420 determines the transmission timing corresponding to the determined congestion class. The timing determining module 1420 increases the transmission window size of the transmission timing as the degree of congestion according to the determined congestion level increases.

For example, in the case of the second stage in which the congestion class corresponds to FIG. 10A, the timing determination module 1420 reduces the transmission window size when the congestion class is low (No). However, if the congestion class is high (Yes), the transmission window size is increased. In addition, when the congestion level is three or four or more levels, the timing determination module 1420 increases the transmission window size of the transmission timing as the degree of congestion increases in the same manner as described above.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and various modifications and variations are possible to those skilled in the art to which the present invention pertains. Do.

Operations according to an embodiment of the present invention may be implemented by a single control unit. In this case, program instructions for performing various computer-implemented operations may be recorded on a computer-readable medium. The computer-determinable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those skilled in the art. Examples of computer readable recording media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD-ROMs or DVDs, magnetic-optical media such as floppy disks and ROMs. Hardware devices specifically configured to store and execute program instructions, such as memory, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. When all or part of the base station or relay described in the present invention is implemented as a computer program, a computer readable recording medium storing the computer program is also included in the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

Claims

A method of operating a transmitting terminal through resource allocation of device to device (D2D) communication in a wireless communication system,

Mapping the D2D control information for the D2D communication to at least one of a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), and a demodulation-reference signal (DM-RS); And

And transmitting the D2D control information mapped to at least one of the PDCCH, the PUSCH, and the DM-RS to a receiving terminal.
The method of claim 1, wherein the mapping of the D2D control information comprises:

And when the D2D control information is mapped to a symbol of the PDCCH, adding at least one of a groupcast ID and a broadcast ID for the group defining the range of the D2D communication to the D2D control information; ,

And mapping the D2D control information appended with the groupcast ID or the broadcast ID to a symbol of the PDCCH.
The method of claim 2, wherein the D2D control information is

Cyclic shift for resource block assignment information, Modulation and Coding Scheme (MCS) information, Redundancy version information, New data indicator information and Demodulation-Reference Signal (DM-RS) (Cyclic shift) information and orthogonal complementary code (OCC) index information, characterized in that any one or more.
The method of claim 2, wherein adding at least one of the groupcast ID and the broadcast ID to the D2D control information comprises:

And masking any one of the groupcast ID and the broadcast ID to a cyclic redundancy code (CRC) to the D2D control information.
The process of claim 2, wherein the mapping of the D2D control information to a symbol of a PDCCH is performed.

Convolution coding the D2D control information added with the groupcast ID or the broadcast ID;

Matching a transmission rate for the convolutionally coded D2D control information;

Scrambling the D2D control information whose rate is matched using any one of the groupcast ID and the broadcast ID;

Modulating the scrambled D2D control information;

Interleaving the modulated D2D control information; And

And group-specific cyclic shift of the interleaved D2D control information.
The method of claim 1, wherein the mapping of the D2D control information comprises:

Convolution coding the D2D control information when the D2D control information is mapped to a symbol of the PUSCH;

Matching a transmission rate for the convolutionally coded D2D control information;

Modulating the D2D control information with matching data rates;

And multiplexing the modulated D2D control information with the modulated data information of the PUSCH.
The method of claim 6, wherein the D2D control information

Cyclic shift for resource block assignment information, Modulation and Coding Scheme (MCS) information, Redundancy version information, New data indicator information and Demodulation-Reference Signal (DM-RS) (Cyclic shift) information and orthogonal complementary code (OCC) index information, characterized in that any one or more.
The method of claim 6, wherein the multiplexing of the D2D control information with the data information comprises:

And mapping to symbols nearest to the demodulation-reference signals (DM-RSs) of the PUSCH.
The method of claim 1, wherein the mapping of the D2D control information comprises:

And when mapping the D2D control information to the DM-RS, mapping new data indicator information as the D2D control information.
The method of claim 9, wherein the mapping of the D2D control information comprises:

And using a parameter value having a size of 1 bit as the new data identifier information.
In the operation method of the receiving terminal through the resource allocation of the device to device (D2D) communication in a wireless communication system,

When the D2D control information for the D2D communication is mapped and transmitted to at least one of Physical Downlink Control CHannel (PDCCH), Physical Uplink Shared CHannel (PUSCH), and Demodulation-Reference Signals (DM-RS), the D2D control information is transmitted. Receiving at least one of the mapped PDCCH, the PUSCH, and the DM-RS; And

Restoring at least one of the received PDCCH, the PUSCH, and the DM-RS to extract the D2D control information.
A method of operating a transmitting terminal through resource allocation of device to device (D2D) communication in a wireless communication system,

Setting a resource structure to include at least one resource pool having a plurality of resource blocks based on a predetermined time; And

Allocating a resource for a signal to be transmitted by shifting the resource blocks included in the resource pool on a time axis every predetermined time; And

And transmitting the signal to a receiving terminal by using the allocated resource.
A method of operating a receiving terminal through resource allocation of device to device (D2D) communication in a wireless communication system,

When a resource for a signal is allocated according to a resource structure including at least one resource pool having a plurality of resource blocks based on a predetermined time, from a transmitting terminal through the allocated resource Receiving the signal; And

Decoding the received signal.
A method of operating a transmitting terminal through resource allocation of device to device (D2D) communication in a wireless communication system,

Receiving signals for the D2D communication for a predetermined time;

Detecting energy levels of each of the resource blocks corresponding to the signals received during the predetermined time; And

Determining a transmission timing of data for the D2D communication according to the congestion class corresponding to the detected energy levels.
An apparatus of a terminal using resource allocation of device to device (D2D) communication in a wireless communication system to perform all claims or claims of claim 1.