KR20150004256A - Appratus and method for allocating resource in device to device communication in wireless network - Google Patents

Abstract

The present invention relates to an apparatus and a method for allocating resource in device to device communication in a wireless network. In an apparatus and a method for allocating resource in device to device communication in a wireless network according to an embodiment of the present invention, the present invention includes a process of requiring resource allocation with regard to a resource block to a base station; and a process of receiving resource allocation with regard to the resource block from the base station. The process of receiving resource allocation is to allocate the time of the resource block and the positon of frequency.

Description

[0001] APPARATUS AND METHOD FOR ALLOCATING RESOURCE IN DEVICE TO DEVICE COMMUNICATION IN WIRELESS NETWORK [0002]

The present invention relates to a wireless network, and more particularly, to an apparatus and a method for allocating resources in direct communication between devices.

Recently, with the proliferation of wireless devices supporting wireless data communication such as smart phones, efficient use of wireless resources has become a technical issue as well as a social issue. Among the technologies that reflect such a demand, there is a growing interest in direct (D2D: Device-to-Device) communication that performs direct communication between users of wireless devices without using a base station and a network.

D2D communication performed in a wireless network not only increases the efficiency of wireless resources, but also has advantages such as reduction of power consumption of device and network and expansion of service area of wireless network. In addition, D2D communication can efficiently distribute the load of the base station due to the support of the large capacity contents by using the proximity of the device.

The D2D communication can be directly used for mobile-to-mobile (M2M) communication, machine-to-machine communication (M2M), terminal-to-terminal (T2T) And peer-to-peer (P2P) communication.

Based on the D2D communication, it is necessary to transmit a search signal for searching for a neighboring terminal in the terminal, and a resource allocation scheme for supporting the search signal should be provided.

The present invention provides an apparatus and method for a base station to allocate resources of D2D discovery according to a resource request of D2D terminals.

The present invention provides an apparatus and method for allocating resources in direct communication between devices in a wireless network that minimizes overhead increase in resource allocation.

The present invention provides an apparatus and a method for allocating resources in direct communication between devices in a wireless network that controls priority of resource block (RB) selection for transmitting a search signal when priority is given to discovery.

The present invention provides an apparatus and method for allocating resources in direct communication between devices in a wireless network that allocates resources efficiently.

A base station for which a resource allocation is requested from a terminal may transmit data or control information for direct communication between resources or resources to transmit discovery information to the terminal through permanent resource allocation, semi-permanent resource allocation, or dynamic resource allocation. A device and method for allocating resources in direct communication between devices in a wireless network that allocates resources to be transmitted.

A resource allocation method according to an embodiment of the present invention is a resource allocation method in direct communication between devices in a wireless network, the resource allocation method comprising: requesting resource allocation for a resource block for direct communication between devices to a base station; And receiving a resource allocation for the resource block from the base station, wherein a time or frequency of the resource block is allocated to the resource block.

A resource allocation method according to an embodiment of the present invention is a resource allocation method in direct communication between devices in a wireless network, the method comprising: receiving a resource allocation request for a resource block for direct communication between devices from a terminal; And allocating resources for the resource block to the terminal, wherein the resource allocation step allocates time or frequency positions of the resource blocks.

A resource allocation apparatus according to an embodiment of the present invention is a resource allocation apparatus for direct communication between devices in a wireless network, the resource allocation apparatus comprising: a base station for requesting resource allocation for a resource block for direct communication between devices to a base station; And a controller for allocating resources for a resource block, wherein the controller is allocated a time or frequency location of the resource block.

A resource allocation apparatus according to an embodiment of the present invention is a resource allocation apparatus for direct communication between devices in a wireless network, comprising: a resource allocation request for a resource block for direct communication between devices from the terminal; And a controller for allocating resources for the resource blocks, wherein the controller allocates time or frequency positions of the resource blocks.

A method of requesting a resource allocation according to an embodiment of the present invention includes a step of acquiring information on a resource block for direct communication between devices via a received SIB ; Scanning an energy level for the resource block; Determining whether a predetermined condition is satisfied as a result of the scanning; And requesting a base station to allocate a dynamic resource when the predetermined condition is satisfied.

A method of requesting a resource allocation according to an embodiment of the present invention includes a step of receiving a dynamic resource allocation request from a terminal to a base station in a direct communication between devices in a wireless network, Acquiring information on a resource block for direct communication between devices through a SIB (system information block), scanning an energy level of the resource block, and determining whether a predetermined condition is satisfied as a result of the scanning operation .

A resource allocation request apparatus according to an embodiment of the present invention is a resource allocation request apparatus for direct communication between devices in a wireless network, the apparatus comprising: And a control unit for requesting a base station to allocate a dynamic resource if the energy level of the resource block is scanned and the scanning result satisfies a predetermined condition and the predetermined condition is satisfied, .

A method of requesting a resource allocation according to an embodiment of the present invention includes a step of transmitting a resource allocation request for direct communication between devices to a base station in a method of requesting resource allocation in direct communication between devices in a wireless network , The UE receiving PDCCH (Physical Downlink Control CHannel) transmitted from the BS, acquiring resource block information for D2D signal transmission through the PDCCH, and transmitting the resource block information from the resource, D2D terminals that do not perform data communication and control information transmission for direct communication between devices: D2D receiving terminals) includes a process of receiving all resources of a corresponding resource area through which a D2D signal is transmitted through the SIB .

A resource allocation requesting apparatus according to an embodiment of the present invention includes a controller for receiving a resource allocation request from a terminal to a base station when a predetermined condition is satisfied in a device for requesting resource allocation in direct communication between devices in a wireless network , The terminal acquires information on a resource block for direct communication between devices through a received SIB (System Information Block), scans an energy level of the resource block, and determines whether the predetermined condition is satisfied And judging whether or not the current time is equal to the current time.

The present invention can minimize the overhead increase in resource allocation.

The present invention can efficiently control the priority of RB selection when there is a priority in direct communication between devices.

The present invention can be allocated to use resources efficiently.

1 is a frame structure diagram illustrating an example of a static allocation method and a dynamic allocation method in an LTE system according to an embodiment of the present invention;
Figure 2 is an example of a method by which a base station allocates D2D resources in a static (or semi-static) allocation method according to an embodiment of the present invention;
3 is another example of a method by which a base station allocates D2D resources in a static (or semi-static) allocation method according to an embodiment of the present invention;
FIG. 4 is a flowchart illustrating an example of a discovery resource allocation method according to an embodiment of the present invention; FIG.
FIG. 5 illustrates an example of a DRAR transmission method according to an embodiment of the present invention; FIG.
6 is an illustration of a method for reporting SRBI according to an embodiment of the present invention;
FIG. 7 is a flowchart illustrating an example of a method of operation in a base station according to an embodiment of the present invention; FIG.
8 is a diagram illustrating a method of allocating resources using signal strengths or signal-to-interference and noise ratios of neighbor base stations measured by a D2D terminal in a base station according to an embodiment of the present invention;
FIG. 9 illustrates an example of paging terminals that need to receive D2D discovery and communication at a base station, which is an embodiment of the present invention;
FIG. 10 is a flowchart illustrating a resource allocation method according to another embodiment of the present invention; FIG.
11 is a diagram illustrating a discovery process of a D2D terminal located in the same cell when using the network discovery method according to an embodiment of the present invention;
12 is a diagram illustrating a configuration of a terminal in direct communication between devices in a wireless network according to an embodiment of the present invention;
13 is a diagram illustrating a configuration of a base station in direct communication between devices in a wireless network according to an embodiment of the present invention;
14 is a frame structure diagram for D2D included in the downlink;
15 is a frame structure diagram for D2D included in the uplink; And
FIG. 16 illustrates a greedy approach in which each mobile station distributes resources to transmit its discovery information in a static allocation method to which the present invention is compared; FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same components are denoted by the same reference numerals as possible in the accompanying drawings. Further, the detailed description of well-known functions and constructions that may obscure the gist of the present invention will be omitted.

Also, the terms and words used in the present specification and claims should not be construed to be limited to ordinary or dictionary meanings, and the inventor is not limited to the concept of terms in order to describe his invention in the best way. It should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be properly defined.

In the embodiment of the present invention to be described later, a wireless network supporting direct communication between devices will be described as a D2D network. However, the technical structure proposed in the embodiment of the present invention should not be construed as being limited to the D2D network. That is, the technical structure proposed in the embodiment of the present invention can be equally applied to a wireless network or a cellular system supporting direct communication between devices. In particular, in an embodiment of the present invention, a transmitting terminal in the wireless network initiates an operation in response to driving of an application selected based on D2D communication with at least one receiving terminal. The transmitting terminal transmits a discovery signal or discovery information to discover at least one receiving terminal to form a link according to D2D communication. That is, this means a series of processes for informing another terminal located at a close distance of the identity and interest of the transmitting terminal. At this time, the identity and the interest may be an identifier (ID) of the terminal, an application identifier, a service identifier, or the like, and may be variously configured according to the D2D service and the operation scenario.

It is assumed that the hierarchical structure of the D2D terminal is composed of a D2D application layer, a D2D management layer, and a D2D transport layer, though it is not shown in the figure. The D2D application layer refers to a D2D service application program driven by a terminal operating system (OS), and the D2D management layer is responsible for converting the discovery information generated in the D2D application program into a format suitable for the transport layer. Means the physical layer / MAC layer (PHY / MAC) layer of the LTE or Wi-Fi wireless communication standard. At this time, inter-terminal discovery may have the following procedure. When the user executes the D2D application program, information for discovery is generated in the application layer and transmitted to the D2D management layer. The D2D management layer converts the discovery information received from the D2D application layer into a management layer message. The management layer message is transmitted through the transport layer of the MS, and the MSs receiving the management layer message perform a reception operation in a reverse order of the transmission process.

Meanwhile, the inter-terminal communication is a communication method for directly transmitting traffic between terminals without going through an infrastructure such as a base station or an access point (AP). At this time, inter-terminal communication can be performed between the terminals without performing the inter-terminal discovery process and then performing communication based on the result (i.e., with the dis- tributed terminals) or without inter-terminal discovery process. The necessity of the inter-terminal discovery process before the inter-terminal communication can be changed according to the D2D service and the operation scenario.

D2D service scenarios can be broadly categorized into commercial services (eg, commercial services or non public safety services) and public safety services. Each service may include a myriad of use cases, but representatively examples are advertisements, social network services (SNS), games, public safety, and public safety services .

1) Advertisement: A network operator who supports D2D can use pre-registered shops, cafes, movie theaters, restaurants, etc. to communicate their identities to D2D users located at close distances using inter-terminal discovery or inter- can do. At this time, interests can be advertisers' promotions, event information, discount coupons, and the like. Among D2D users, those who are interested in discounting and couponing a specific product upload their interests to the D2D server. If the identity received by the D2D users matches the user's interests, the user can visit the store and obtain more information using existing cellular network or inter-terminal communication. In another example, an individual user can discovery a taxi located in the vicinity of the user through the inter-terminal discovery, and exchange data on the destination, charge information, and the like through the existing cellular communication or inter-terminal communication.

2) SNS (social network service): The user can send his / her application and the interest of the application to other users located in the adjacent area. At this time, the identity or the interest used in inter-terminal discovery may be a friend list or an application identifier of the application. After the user performs the inter-terminal discovery, the user can share the contents of his / her photos, videos, etc. with the nearby users through the inter-terminal communication.

3) Game: The user discovers users and game applications through the inter-terminal discovery process in order to enjoy a mobile game with users located in close proximity, and performs communication between the terminals in order to transmit data necessary for the game can do.

4) Public safety and public safety services: Police officers and firefighters may use D2D communication technology for public safety purposes. That is, if cellular networks are partially destroyed due to an emergency such as a fire or landslide, or natural disasters such as earthquakes, volcanic eruptions, or tsunamis, police and firefighters can use D2D communication technology to discover nearby associates The emergency information of each user can be shared among the adjacent users.

The D2D terminal described below may include one of a transmitting terminal and a receiving terminal. In this specification, a cellular terminal and a D2D terminal can be distinguished from each other. The cellular terminal can communicate with a base station or another terminal using a conventional cellular communication network without a direct link between the terminals. The D2D terminal refers to a terminal that performs D2D discovery or D2D direct communication through a direct link between terminals. At this time, the D2D terminal can perform communication with the base station for transmission and reception of various control information. The term " terminal " used in this specification without any particular distinction can be interpreted to refer to a cellular terminal as well as a D2D terminal.

The terminal described below may operate only discovery without communication, may operate separately communication only without discovery, or may operate in conjunction with discovery and communication (communication after discovery).

There are two types of resource allocation methods for transmitting the discovery signal.

The first method is a static or semi-static resource allocation method.

When a static or semi-static resource is allocated, the base station allocates resources through a system information block (SIB) transmitted in a downlink frame. For example, the base station transmits resource allocation information for a D2D discovery signal to a system information-radio network temporary identifier (SI-RNTI) or a D2D radio network temporary identifier (D2D-RNTI) common to all D2D terminals existing in a base station, Scrambling the data to a physical downlink control channel (PDCCH). That is, the presence of the SIB is known by the transmission of the PDCCH indicated by SI-RNTI (or D2D-RNTI). All terminals in the cell know the SI-RNTI (or D2D-RNTI) in advance and acquire the SIB allocation information from the PDCCH using the SI-RNTI (or D2D-RNTI). The SIB 110 is transmitted through a physical downlink shared channel (PDSCH). That is, the UE obtains the resource allocation information of the SIB allocated to the PDSCH from the PDCCH, decodes the SIB, and finally obtains the resource allocation information 120, 140 for the D2D discovery signal transmission. The SIB 110 may include resource pool information for a D2D receiving terminal and resource pool information for a D2D transmitting terminal. The resource pool information includes information about a resource area (number of subframes) on a time axis, a period of the time axis resource area, and a resource area of a frequency axis (for example, a D2D application in a subframe) that can use D2D discovery or D2D communication The number of resource blocks (hereinafter referred to as "RBs") included in the resource blocks. When resources for D2D discovery signal transmission or D2D terminal communication are allocated through the static or semi-static resource allocation method, terminals desiring D2D transmission are distributed D2D And selects a resource (e. G., RB) for transmission. That is, the D2D terminals select the RB for D2D transmission in a greedy manner, and the following procedure is followed.

1) During the predefined peer discovery interval, measure the energy level of all RBs in the interval.

2) The RB having the lowest energy level among the measured RBs is selected, and the peer discovery information is transmitted to the selected RBs, or one of the RBs whose energy level is within the lower x% (for example, 5% random), and transmits the peer discovery information to the selected RB.

In addition to the greedy method, D2D terminals can randomly select resources. That is, D2D transmission can be performed by selecting one RB at random in the D2D transmission resource region.

The second method is a dynamic resource allocation method.

When allocating dynamic resources, the base station uses the same method as that used for allocating downlink resources and uplink resources of terminals in a conventional LTE (Long Term Evolution) system. That is, downlink resources or uplink resources can be allocated to terminals that want to transmit a D2D signal through a PDCCH transmitted in a downlink frame. In the existing LTE system, resource allocation for the downlink means resources to be received by the UE, and resource allocation for the uplink means resources to be transmitted by the UE.

However, in the D2D communication scheme, when a downlink resource is allocated for transmission of a D2D signal, a base station sets transmission terminals transmitting a D2D signal to transmit in allocated downlink resources, and receiving terminals receiving a D2D signal allocate The base station should set it to receive the downlink resource. For this operation, the D2D transmitting terminal must receive the transmission in the downlink, and the D2D receiving terminal must receive the transmission.

Also, when uplink resources are allocated for the transmission of the D2D signal, the base stations set up the transmitting terminals transmitting the D2D signal to transmit in the allocated uplink resources, and the receiving terminals receiving the D2D signal transmit the allocated uplink resources The base station must set it to receive. For this operation, the operation in which the D2D transmitting end of the uplink receives the transmission and the D2D receiving end receives the uplink should be supported.

A general resource allocation method allocates D2D resources through a static resource allocation method, and a terminal to transmit a search signal in the allocated D2D resource selects a RB to be used by itself in a greedy or random manner. In such a static resource allocation method, Greedy (or random resource selection) scheme has difficulty in congestion control or load balancing. That is, when a terminal that transmits a search signal by the Greedy method scans an energy level, congestion occurs when the energy level of the RB is similar to the high energy level. However, there is no way to solve this problem. In addition, there may be a method in which the UE itself performs a random back-off, but basically, the period of discovery in the static resource allocation method may be long, so that a delay requirement such as a real- There is no way to solve this problem. Also, there is no way to control the priority of RB selection when there is priority in discovery. Also, in the random resource selection scheme, since the D2D transmitting terminal randomly selects the D2D transmission resources to be used without any prior information, congestion control, load balancing, and discovery If there is a priority, there is no way to control the priority of RB selection.

Meanwhile, in a conventional cellular system, when a base station allocates resources to a mobile station, resource allocation is performed through a semi-persistent allocation, a persistent allocation, and a dynamic allocation. However, it should be noted that the D2D discovery is in a state before a link is formed between D2D terminals, so that control signaling that has been performed for resource allocation in the existing cellular system can not be directly applied to D2D discovery. Also, in the direct communication between the D2D terminals considered in the current LTE Rel-12, only the multicast / broadcast communication in which L1 / L2 (layer 1 / layer 2) feedback is impossible is supported. Therefore, A resource allocation scheme and signaling can not be applied directly to D2D terminals. Therefore, an additional control signaling scheme is required for resource allocation in D2D discovery / communication, and an increase in additional overhead should be minimized when designing such control signaling. The present invention relates to a resource allocation method and apparatus for D2D signal transmission (E.g., congestion, delay requirement, priority) for requesting resource allocation to a base station, a method for requesting resource allocation, and a method for allocating a discovery resource to a base station requested by the terminal.

The D2D terminal can acquire resource allocation information for D2D transmission and reception through the SIB. That is, the base station transmits resource allocation information to the D2D terminals existing in the corresponding cell through the SIB (i.e., a subframe), or from a few subframes to a few subframes for D2D transmission or reception (E.g., how many cycles the subframes are allocated, how many RBs are allocated as D2D resources in the subframe, etc.), and each D2D terminal transmits discovery information in the corresponding D2D subframe An RB for transmitting data (D2D data) and control information (SA: Scheduling Assignment) for direct communication between terminals is a general resource allocation method (Greedy method or a method of allocating resources) in a D2D resource area Random resource selection method), or the base station may determine the transmission RB and transmit the D2D transmission Can be assigned to the terminal. When a base station allocates RBs for D2D transmission to a mobile station, the mobile station can allocate and allocate resources or time positions of dynamically allocated resources to specific D2D mobile stations for each subframe. Alternatively, Time or an RB with the same frequency location (permanent or semi-permanent resource allocation). On the other hand, when a specific subframe is allocated for D2D discovery or communication via the SIB, a terminal that does not transmit discovery information or a terminal that receives D2D communication transmits discovery information or communication transmitted from the corresponding D2D subframe (I. E., Decodes) data and control information.

1) Condition for requesting D2D resource allocation to the BS by the MS: Discovery information or terminals for transmitting communication data and control information may request the D2D resource allocation to the BS for the following reasons.

- According to the above-mentioned general resource allocation method, when the terminal itself determines the RB to transmit discovery information, when considering congestion or load balancing, the D2D terminal can request resource allocation from the base station. That is, when the energy level of all the RBs is higher than the specific threshold value, or when there is no RB whose energy level is lower than the specific threshold value, or when the energy level of the RB is lower than the specific threshold value, D2D UEs can request resource allocation from the BS when there is not much margin and when the number of RBs whose energy level is lower than a certain threshold is less than a specific number.

In the process of D2D terminals participating in discovery with priority (for example, a priority according to a delay requirement) of a certain value or more when the terminal itself determines an RB to transmit discovery information according to the above-mentioned general resource allocation method, If the energy levels of all RBs are higher than a certain threshold, the D2D terminals can request resource allocation from the base station. At this time, priority (delay requirement class) information is transmitted to a logical entity (not shown) existing in the network when an initial entry of the D2D terminal or an application of the D2D terminal is turned on or executed. For example, a priority processing unit or a delay request processing unit). The location of the logical entity may be located separately in the D2D server or the application server, or may be located in an MME (Mobility Management Entity), an S-Gateway (Serving Gateway), a P-Gateway (Packet Data Network Gateway)

- According to the above-mentioned general resource allocation method, when the UE itself determines the RB to transmit discovery information, the amount of discovery information increases, so that the BS can request additional resource allocation. For example, in the process of D2D UEs having a priority (delay requirement class) of 3 or more participating in discovery, although the energy level of all RBs is not higher than the specific threshold value, the amount of discovery information changes, This is the case.

In the case where the base station does not support the above-mentioned general resource allocation, a terminal that desires to transmit D2D discovery or communication data and control information requests a base station to allocate resources, and the base station transmits D2D discovery or communication data and control information To the terminal. When allocating an RB for transmitting D2D discovery or communication data and control information to a terminal, the terminal can dynamically allocate a time or a frequency position of a resource to each specific D2D terminal for each subframe. Alternatively, The same time or frequency location can be equally allocated to consecutive subframes (permanent or semi-permanent resource allocation). At this time, the UE can request the D2D transmission resource to use for its own according to its payload size (i.e., the size of the discovery information, the size of the communication data, and the control information).

2) A method in which a terminal requests resource allocation to a base station: Consider three methods as a method for a terminal to request a resource allocation.

First, the terminal transmits a D2D Resource Allocation Request (DRAR) to the base station.

Second, the terminal transmits a D2D DBSR (Buffer Status Report) to the base station.

Third, the terminal reports the index of the RBs selected by the base station to the base station.

- D2D DRAR: This is similar to the scheduling request (SR) in which the UE requests resource allocation from the base station to the base station in the existing LTE-A. In LTE-A, the SR is 1-bit information, and is transmitted through a physical uplink control channel (PUCCH), which is an uplink control channel. More specifically, a PUCCH format 1 (only SR), a PUCCH format 1a (transmission of 1-bit HARQ ACK / NACK and SR), and a transmission of a PUCCH format 1b (2-bit HARQ ACK / NACK and SR) ) Is used. Since the SR of the current LTE-A is a resource request for the cellular terminals, a separate SR is required for the D2D terminals. In the present invention, PUCCH format 2 (CSI: Channel State Information), PUCCH format 2a (transmission of CSI and 1-bit HARQ ACK / NACK), or PUCCH format 2b 1-bit SR information can be added to the CSI (2-bit HARQ ACK / NACK transmission).

The prerequisite of DRAR is that all D2D terminals use the same size of search signal transmission resources. Therefore, the base station can allocate resources to the D2D transmitting terminals even when receiving only DRAR, which is 1-bit information. However, it is not limited to this method.

In LTE-A, control information such as CQI (Channel Quality Indicator), PMI (Precision Matrix Index), RI (Rank Indicator) and HARQ ACK may be fed back to the base station through a physical uplink shared channel have. In the present invention, the DRAR can be transmitted to the base station through the PUSCH like the control information.

- DBSR (D2D Buffer Status Report): In the resource allocation request through DRAR mentioned above, there is a precondition that all D2D terminals use search signal transmission resources of the same size. If the size of the search signal transmission resource differs for each D2D terminal (in particular, when D2D data and control information are transmitted in inter-terminal direct communication), the base station recognizes this and allocates a necessary amount of D2D transmission resources to each D2D terminal . In the conventional LTE-A, the UE transmits its own buffer state, that is, the size of data accumulated in the buffer (Buffer Status Report: BSR), and the base station allocates uplink resources of the UE based on the buffer status report. The BSR of LTE is transmitted in the MAC PDU. Since the BSR of the current LTE-A is a resource request for the cellular terminals, a separate BSR for the D2D terminals is required. To do this, a change to LTE-A is required (addition of a logical channel identifier for the DBSR), which is the same as the index report of the selected RBs described below.

- Index reporting of selected RBs: Unlike DRAR which transmits only 1-bit information, the index report of selected RBs may require feedback of many bits. Therefore, it may be desirable to transmit through higher layer signaling rather than to a physical channel such as PUCCH or PUSCH. A variety of logical channel identifiers (LCIDs) can be multiplexed in the MAC header of the LTE-A, and the LCID can be multiplexed with a buffer status report (BSR) and a power headroom report Different MAC control elements are indexed according to their use. D2D discovery Additional MAC control elements and LCIDs are required when reporting the indexes of the selected RBs for resource requests. Meanwhile, a padding bit or a dummy bit is selectively inserted at the end of the MAC PDU, and the index of the selected RBs can be designed using this portion.

3) Method of allocating resources to the transmitting D2D terminal by the base station: In order for the base station to allocate resources to be used by the transmitting D2D terminal, the base station instructs the D2D terminals requesting resource allocation to measure and report signals of the neighboring base stations D2D terminals periodically report signals of neighboring base stations to the base station in the cellular mode. Since the base station can roughly predict the position of each transmitting D2D terminal using the measurement result from the transmitting D2D terminal, the base station performs resource allocation based on this. That is, when the location of the transmitting D2D terminal requesting resource allocation is far away, the resources are allocated to transmit the discovery signal from the same resource, and when the location of the transmitting D2D terminal requesting resource allocation is relatively close, Resources can be allocated to send a discovery signal on the resource. Also, prior to the resource allocation, the BS may independently determine whether the resource to be allocated to the transmitting D2D UE causes interference to the cellular terminals located in the cell managed by itself or the cellular terminals located in the adjacent cell, or If it determines that it can cooperate with neighboring cells and cause interference, it instructs it to stop allocating resources or perform discovery in the next discovery subframe.

4) Method to enable reception of D2D terminals: In the D2D discovery phase, the link connection is not yet established between the D2D terminals and the D2D communication operates in the broadcast mode. Therefore, the discovery information transmitted by the D2D transmitting terminal is transmitted to the D2D transmitting terminal D2D terminals located in the < / RTI > It should be noted that all terminals operate in idle mode most of the time to reduce power consumption. That is, all UEs receive a physical downlink control channel (PDCCH) transmitted from the Node B in an On duration mode (or an active period) according to a discontinuous reception (DRX) cycle of each UE. The PDCCH is transmitted every subframe, and the number of subframes during which the UE should decode the PDCCH depends on the On duration timer of each UE. In the remaining time except the On duration mode, the terminal operates in the idle mode and does not receive the PDCCH transmitted by the base station. Therefore, the base station must perform paging so that the D2D terminals can receive the discovery information, i.e., the terminals in the idle mode receive the PDCCH. To this end, the Node B measures the difference between the time at which the BS performs the dynamic resource allocation and the time at which the D2D UE receives the PDCCH in the On duration mode (the difference is referred to as offset), and the offset is equal to or less than a predetermined threshold It instructs the terminal to keep awake only.

1 is a frame structure diagram illustrating an example of a static allocation method and a dynamic allocation method in an LTE system according to an embodiment of the present invention.

Figure 1 illustrates a frequency division duplexing (FDD) system, but is not limited to an FDD system. In the FDD system, the downlink and uplink use different frequency bands. As shown in FIG. 1, one frame 100 having a length of 10 ms is composed of 10 subframes. One subframe consists of two slots. Although not shown in FIG. 1, seven slots are used when a normal CP (Cyclic Prefix) is used in one slot, and six symbols are used when an extended CP is used (OFDM symbol in the downlink and uplink in the uplink) SC-FDMA symbol).

In the static allocation for D2D discovery, the resource allocation information is transmitted through the SIB (System Information Block), and the transmission period of the SIB can be designed to be 40 ms to 640 ms or longer. D2D terminals synchronize downlink through a system and a synchronization signal, and receive information of a cell connected to the D2D by using a master information block (MIB) transmitted through a PBCH (Physical Broadcast CHannel). For example, the MIB includes essential parameter information such as a DL system bandwidth, a system frame number, and a PHICH (physical hybrid-ARQ indication channel) setting. The terminals receiving the MIB can receive the PDCCH transmitted from the base station for each subframe. Basically, the PDCCH transmits downlink / uplink resource allocation information. Each UE decodes the SIB resource allocation information existing in the PDCCH using a known SI-RNTI. That is, information on the frequency-time domain in which the SIB is located is known through decoding of the PDCCH using the SI-RNTI, and the SIB is decoded through decoding in the frequency-time domain. Successfully decoded SIBs obtain the discovery subframe information contained in the SIB, so that information on the number of subframes (s) or consecutive subframes in the frame is the discovery purpose subframe and information on the period of the discovery subframe. If the location of the discovery subframe changes within the frame (for example, if the discovery subframe changes from the third subframe to the fifth subframe, or when the amount of the discovery subframe increases from one subframe to two subframes) ), You can tell the change via the SIB, or you can tell the change via the paging channel. A terminal transmitting D2D discovery information may select a discovery resource to transmit itself to itself in the corresponding subframe (s), or a base station may select a discovery resource and notify the terminal of the discovery resource. Meanwhile, the UE receiving the D2D discovery information receives and decodes the corresponding discovery subframe (s) allocated through the SIB. In the discovery subframe, there are PUCCHs for transmission of cellular uplink feedback (SR, HARQ ACK / NACK, etc.) in the upper and lower portions along the frequency axis. Since the number of RBs occupied by the PUCCH in each subframe may be variable according to the scheduling of the base station, discovery resource allocation information included in the SIB may be used for discovery to inform that RBs other than the number of RBs of the PUCCH can be used for discovery. The number of RBs may be included.

Unlike the static allocation method in which the resource allocation information is transmitted through the SIB, the resource allocation information is transmitted through the PDCCH in the dynamic allocation method. This is the same as the transmission of the resource allocation information of the cellular terminal in the existing LTE system. However, unlike existing cellular systems, D2D terminals in D2D discovery are not yet configured for linking. Therefore, an unspecified number of D2D terminals should receive discovery information. That is, in the existing LTE, the transmitting and receiving UEs transmit allocation information on resources to be used by each PDCCH, and each UE uses its C-RNTI (Cell-Radio Network Temporary Identifier) Can be obtained. However, due to the broadcast nature of discovery in the D2D communication scheme, the transmitting D2D UE can acquire information on the resource allocation region to be transmitted from the PDCCH using its C-RNTI when performing dynamic allocation, , It is necessary to define a new RNTI for the receiving D2D terminals. When the D2D terminal does not transmit in the D2D discovery process, all the D2D resource regions must be received. Therefore, rather than allocating the C-RNTIs individually, the D2D receiving terminals acquire information on the common resource allocation region in one RNTI RNTIs for broadcast or RNTIs for groupcasts are needed. In the present invention, this is referred to as D2D-RNTI. All D2D receiving terminals that do not send discovery information use the D2D-RNTI to obtain information about the resource area that they should receive.

FIG. 2 illustrates an example of how a base station allocates D2D resources in a static (or semi-static) allocation method according to an embodiment of the present invention.

2, it is assumed that D2D transmission / reception is performed in an uplink band in a frequency division duplex (FDD) system. A wide area network (WAN) is a subframe for uplink data transmission in a cellular terminal, and D2D represents a subframe for D2D discovery or D2D communication. 2, one radio frame 220 is composed of 10 subframes, six subframes within one radio frame 220 are allocated for cellular uplink communication, and the remaining four subframes are allocated to D2D It is assumed to be assigned as a resource. In FIG. 2, four consecutive subframes are allocated as D2D resources, but they may not be consecutive subframes. These D2D resources are repeatedly allocated every discovery period (240). The base station informs the location of the D2D reception pool (210, 230) via the SIB, and the D2D transmission pool can inform via the SIB. Consider, for example, when two different D2D transmission modes, such as the static allocation method and the dynamic allocation method, are simultaneously supported. The D2D receiving terminal must receive all areas regardless of static allocation or dynamic allocation. Therefore, in the case of the D2D receiving terminal, it is possible to receive the D2D by only having the D2D reception resource pool information through the SIB. However, the D2D transmission resource pool has to be transmitted to the D2D terminal through separate signaling because the allocated resources are different in the static allocation method and the dynamic allocation method. For example, when the reception resource pool = 4 subframes (subframe indices 4, 5, 6, 7) are allocated in transmission resource pool = 3 (subframe indexes 4, 5, 6) , The D2D receiving terminal receives four subframes corresponding to the subframe indices 4, 5, 6 and 7, and the D2D transmitting terminal receives the Greedy method or the random resource in three subframes corresponding to the subframes 4, 5, Select RB for D2D transmission by selection. The remaining subframe indexes (index 7) indicate that the base station is a resource used for dynamic resource allocation. When a base station performs dynamic resource allocation, a D2D transmitting terminal that has requested a D2D transmission resource through PDCCH or RRC signaling to use an RB corresponding to a specific time-frequency within a subframe index (index 7) for D2D transmission Can be assigned.

FIG. 3 is another example of how a base station allocates D2D resources in a static (or semi-static) allocation method according to an embodiment of the present invention, where different D2D transmission modes are FDM in the D2D reception pool. Referring to FIG. 3, as in FIG. 2, the D2D terminal receives the D2D reception pool 310 and 330 through the SIB. The D2D receiving terminal receives and decodes all RBs located in the D2D reception pools 310 and 330. [ The D2D resources are repeatedly allocated every discovery period (340). Meanwhile, in order to support different D2D transmission modes of the static resource allocation and the dynamic resource allocation, the base station transmits the number of RBs on the frequency axis for static allocation through the SIB.

In FIG. 3, the RB number of the static allocation and the dynamic allocation is illustrated as being the same for every subframe, but may be different for each subframe. In this case, the number of RBs that can be used for the static allocation for each subframe must be informed to the D2D terminals through the SIB. FIG. 4 is a flowchart illustrating an example of a discovery resource allocation method according to an embodiment of the present invention.

The base station receives a dynamic resource allocation request message from the D2D terminals in step 401. [ At this time, the dynamic resource allocation request message may include a D2D DRAR of 1-bit or an index of one RB or a plurality of RBs selected by the D2D transmitting terminal in the discovery subframe. At this time, the index of the selected RB (s) may be several bits or dozens of bits. The DRAR may be transmitted through the PUCCH, which is an uplink control channel, or may be transmitted through a PUSCH, which is an uplink data channel. When DRAR is transmitted on the PUSCH, it is transmitted together with other control information (e.g., a channel quality indicator (CQI), a rank indicator, a precoding matrix indicator (PMI), a hybrid automatic repeat request (HARQ) Can be multiplexed.

Meanwhile, the DBSR or the selected RB index (SRBI) of the selected RB (s) can be transmitted through higher layer signaling. That is, a new LCID indicating the index of the selected RB (s) in the MAC header may be defined, or a padding portion located at the end of the MAC PDU may be used.

After step 401, the base station proceeds to step 403 and transmits to the at least one mobile station that transmitted the dynamic resource allocation request message in step 401 to measure and report a signal of the neighbor base stations.

The base station receives measurement results from at least one of the terminals in step 405.

In step 407, the BS allocates resources to at least one MS based on the measurement result. The base station enables the D2D terminals in the RRC_IDLE state to be able to receive signals simultaneously with the resource allocation.

FIG. 5 illustrates a case of using the uplink data channel PUSCH as an example of the DRAR transmission method according to the embodiment of the present invention.

In LTE-A, control information such as CQI, PMI, RI, and HARQ ACK may be fed back to the base station via the PUSCH. In the present invention, the D2D resource allocation request message such as DRAR can be transmitted to the base station through the PUSCH like the control information. Although not shown in FIG. 5, code block segmentation is performed before channel encoding, a CRC is inserted for each code block, and the FEC is sent to the forward error correction (FEC) stage. The control information such as CQI, PMI, and RI, which are transmitted through the UL-SCH, are subjected to turbo encoding, convolutional encoding, and block encoding, respectively, and their outputs are subjected to rate matching and modulation (Except for RI: RI always uses QPSK modulation).

The multiplexer (MUX) 510 separates the three data that have been separated by the demultiplexer (DEMUX) (not shown in the figure) by each component and passed through the rate matchers 520a to 520c into one data. At this time, the multiplexer 510 multiplexes the D2D resource allocation request message together with the punctured HARQ ACK, as indicated by reference numeral 530.

6 is an illustration of a method for reporting DBSR and SRBI according to an embodiment of the present invention.

LCID is used as an example of a method of reporting DBSR and SRBI according to an embodiment of the present invention.

A variety of logical channel identifiers (LCIDs) can be multiplexed in the MAC header 600 of the LTE-A, and the LCID can be used to index different MAC control elements according to their use, such as buffer status reporting and power headroom reporting (indexing). This is referred to as logical channel indexes 610 and 620 in FIG. D2D discovery For resource allocation requests, additional MAC control elements and LCIDs are required when reporting DBSR and SRBI. For example, DBSR and SRBI can be represented through additional logical channel indexes.

On the other hand, a padding 630 is optionally included in the last part of the MAC PDU, and DBSR and SRBI can be reported using this portion.

7 shows an operation method in a base station, which is an embodiment of the present invention.

In step 701, the BS receives DRAR or DBSR and SRBI. In step 703, the BS receiving the DRAR or SRBI instructs the D2D UEs that have transmitted the DRAR or the DBSR and the SRBI to measure and report the signals of the neighbor BSs. At this time, since the D2D terminals periodically report the signals of the neighboring base stations to the base station in the cellular mode, the D2D terminals may use the reported information as they are. In step 705, the BS receives a result of the received signal strength or the signal-to-interference-and-noise ratio measurement from the neighbor BSs measured by the D2D terminal that has transmitted the DRAR or the DBSR and the SRBI.

In step 707, the BS determines whether resources to be allocated to the transmitting D2D UE cause interference to the UEs. If it is determined that interference can be caused, the BS proceeds to step 711 and instructs the BS to stop resource allocation or perform discovery in the next discovery subframe.

However, if it is determined that it will not cause interference, the base station performs resource allocation based on the result of the measurement in step 709. At this time, since the base station can roughly predict the position of each transmitting D2D terminal using the measurement result from the D2D terminal, the base station performs resource allocation based on this. That is, when the location of the transmitting D2D terminal requesting the resource allocation is far away, the resources are allocated to transmit the discovery signal from the same resource, and when the location of the transmitting D2D terminal requesting resource allocation is relatively close, Resources can be allocated to send a discovery signal on the resource.

8 is a diagram illustrating an example of a method of allocating resources using signal strengths or signal-to-interference and noise ratios of neighbor base stations measured by a D2D terminal in a base station according to an embodiment of the present invention.

For convenience of description, three cells are illustrated according to an embodiment of the present invention, and each cell is composed of three sectors each. The base stations that control each cell are named eNB-1, eNB-2, and eNB-3, and the sectors of each cell are denoted by A, B, and C. In addition, it is assumed that the terminals X1 and Y1 measure and report the signals of the neighboring base stations in the sector C and the sector B of the cell managed by the eNB-1, respectively (i.e., the terminals X1 and Y1 are the terminals that have requested resource allocation). In the sector B of the cell managed by the eNB-2, it is assumed that the terminals X2 and Y2 measure and report signals of neighboring base stations to the base station eNB-2. First, considering the operation of eNB-1, since the signal strengths of neighbor base stations reported by X1 and Y1 may be different from each other, the base station may consider that X1 and Y1 are far apart from each other. Therefore, the base station can perform resource allocation such that X1 and Y1 perform discovery using the same resource 820.

On the other hand, the eNB-2 can determine that the two terminals are not far apart based on the reports of X2 and Y2, and can schedule the resources X2 and Y2 to be allocated resources 810 orthogonal to each other.

FIG. 9 illustrates an example of paging UEs to receive D2D discovery and communication in a base station according to an embodiment of the present invention.

The terminal 1, the terminal 2, the terminal 3 and the terminal 4 receive a physical downlink control channel (PDCCH) transmitted from the base station in the On duration (920) mode according to their respective discontinuous reception (DRX) . Here, the DRX cycle 910 is a distance between an arbitrary activation period and the next activation period. The longer the DRX cycle length, the longer the sleep period, and the lower the power consumption of the terminal. However, if the DRX cycle length is long, a call delay to the UE increases. The DRX cycle length is signaled by the network.

The length of On duration 920 means the length of a period during which the terminal wakes up during one activation period, and a predetermined value is usually used.

The PDCCH is transmitted every subframe, and the number of subframes during which the UE should decode the PDCCH depends on the On duration timer of each UE. In the remaining time except the On duration mode, the terminal operates in the IDLE mode and does not receive the PDCCH transmitted by the base station. Therefore, the base station must perform paging so that D2D terminals can receive discovery information, that is, terminals in IDLE mode wake up to receive a PDCCH. To this end, the BS measures the difference between the point of time at which the Node B performs resource allocation to the UE (930) and the point at which the D2D UE receives the PDCCH in the On duration mode (indicating the difference as offset) It should be instructed to keep awake only to terminals below the threshold. That is, T1, T2, T3, and T4 in FIG. 9 represent offset, which is a difference between a point at which a base station performs resource allocation and a point at which a D2D terminal receives a PDCCH in an On duration mode. Instructs this offset to remain awake only for terminals below a predefined threshold.

Hereinafter, a resource allocation method according to another embodiment of the present invention will be described.

The present invention relates to a resource allocation method and apparatus for transmitting a D2D search signal, and more particularly, to a method and apparatus for allocating resources for a D2D search signal, in which a terminal operating in static / semi-static resource allocation allocates conditions (congestion, delay requirement, priority) A method for requesting resource allocation, and a method for allocating a discovery resource to a base station to which the request is made.

10 is a flowchart illustrating a resource allocation method according to another embodiment of the present invention.

In step 1001, the D2D terminal receives the SIB through the PDCCH. The D2D terminal acquires resource information for the discovery resource area through the SIB received in step 003. Then, in step 1005, the D2D terminal scans the energy levels of the RBs in the discovery resource region.

As a result of the scanning, the D2D terminal determines in step 1007 whether a predetermined condition is satisfied. If the predetermined condition is not satisfied, the D2D terminal transmits a discovery signal in step 1009.

However, if the predetermined condition is satisfied, the D2D terminal transmits a dynamic allocation request message in step 1011 according to an embodiment of the present invention. The condition for switching from the static resource allocation to the dynamic resource allocation, that is, the predetermined condition is as follows.

1) Conditions for switching from static resource allocation to dynamic resource allocation

- Congestion

. Follow-up action: If the energy levels of all RB's are above a certain threshold, or if none of the RB's have an energy level below a certain threshold

. Proactive measures: When there is an RB whose energy level is lower than a certain threshold value but the energy level of the RB is not margin based on the threshold value, or when the number of RBs whose energy level is lower than the specific threshold value is not more than a specific number

- Priority (delay requirement)

. For example, when D2D terminals having a priority (delay requirement class) of 3 or more participate in discovery, when the energy levels of all RBs are higher than a certain threshold value

. At this time, priority (delay requirement class) information is transmitted to a logical entity (not shown in the figure, for example, a priority processing section or a delay request processing section, etc.) existing in the network when an initial entry of the D2D terminal or an application of the D2D terminal is turned on ). ≪ / RTI > The location of the logical entity may be located separately in the D2D server or the application server, or may be located in the MME, the S-gateway, the P-gateway, and the like.

- Change in the amount of Discovery information

For example, in the process of D2D UEs having a priority (delay requirement class) of 3 or more participating in discovery, although the energy level of all RBs is not higher than a specific threshold value, the amount of discovery information changes,

2) The terminal requests the base station to allocate resources

- Congestion post-action, priority, delay requirement: D2D resource allocation request (scheduling request)

- Congestion Precaution: The index report of the selected RB (s)

. If the RB is selected because the RB has an energy level lower than a specific threshold value but the energy level of the RB is not a margin based on the threshold value

. When the number of RBs whose energy level is lower than a specific threshold is less than a specific number

3) A process in which a base station is allowed to receive terminals in idle mode simultaneously with resource allocation

FIG. 11 illustrates a discovery process of a D2D terminal located in the same cell when using the network discovery method according to an embodiment of the present invention.

In step 1101, the BS receives a discovery request from a D2D terminal that desires to perform discovery. Upon receiving the discovery request from the D2D terminal, the base station requests the D2D server to confirm the presence of the D2D terminal or the terminals to be searched in step 1103. That is, the D2D server checks whether it exists in a cell managed by itself or in another cell. At this time, the D2D server refers to a Mobility Management Entity (MME), a Home Subscriber Server (HSS), a Serving Gateway (S-GW), a P-GW (PDN Gateway), a location server or a separate logical entity. In step 1105, the BS receives the existence of the D2D terminal or terminals from the D2D server. In step 1107, the base station confirms from the D2D server that there exists a D2D terminal or terminals to be searched in a cell managed by the terminal. In step 1107, the base station unicasts / multicasts / broadcasts discovery information to the D2D terminals or terminals ).

The present invention can allocate resources through a dynamic resource allocation method without waiting for a relatively long search signal transmission period in order to solve congestion that may occur in a semi-static / static resource allocation method or to satisfy delay requirements . Also, the present invention can dynamically allocate resources for a D2D search signal from a base station when a D2D search signal can not be transmitted due to insufficient resources of D2D terminals having high priority. The present invention can efficiently perform D2D discovery through such resource allocation.

The present invention can allocate a specific subframe or a plurality of subframes for D2D discovery based on the static allocation method as in the prior art. Each terminal that desires to transmit discovery information in a subframe (s) allocated through the static allocation allocates a discovery resource (s) to be transmitted, based on a received energy level of discovery signals received from a terminal located in its vicinity, Can be selected. However, this method can not solve the congestion problem, delay requirements, and priority problems that may occur in the semi-static / static resource allocation method. Since the base station can solve this problem within the coverage of the base station (i.e., in the environment where the base station is present), the terminal can request the base station to allocate the discovery resource when the above-mentioned problem occurs. The base station that has requested resource allocation from the terminal can allocate resources to transmit discovery information to the terminal through permanent, semi-permanent, or dynamic resource allocation.

The present invention enables efficient use of D2D discovery resources with resource allocation with the help of such base stations.

12 is a diagram illustrating a configuration of a terminal in direct communication between devices in a wireless network according to an embodiment of the present invention.

12, the terminal includes a transmission / reception unit 1230, a reception unit 1210, a control unit 1210, a memory unit 1240, and a user interface unit 1220.

The transmitter / receiver 1230 includes a transmitter module and a receiver module for transmitting / receiving data to / from a base station according to an embodiment of the present invention in direct communication between devices in a wireless network. Also, the transmitter / receiver 1230 transmits a message for requesting a resource to the base station. In the embodiment of the present invention, the transmitter / receiver 1230 transmits DRAR or SRBI to the base station.

The transmission / reception unit 1230 detects a peripheral terminal for D2D communication under the control of the controller 1010, and performs an operation for forming a link with all or a part of the detected peripheral terminals. The transmission / reception unit 1230 transmits a search signal under the control of the control unit 1210.

The controller 1220 requests resource allocation to the base station according to an embodiment of the present invention. The control unit 1220 obtains information on a resource block for discovery through the received SIB, scans an energy level of the resource block, determines whether a predetermined condition is satisfied as a result of the scanning, If the condition is satisfied, a dynamic resource allocation is requested to the base station.

The memory unit 1240 stores or extracts various data necessary for requesting assignment of discovery resources to the base station according to an embodiment of the present invention in direct communication between devices in a wireless network.

The user interface unit 1220 transfers information input by a user's operation to the control unit 1210 or provides necessary information to the user under the control of the control unit 1210. [

13 is a diagram illustrating a configuration of a base station in direct communication between devices in a wireless network according to an embodiment of the present invention.

13, the base station includes a transmission / reception unit 1320, a memory unit 1330, and a control unit 1210.

The transmitter / receiver 1320 transmits / receives data in order to allocate discovery resources to the terminal according to an embodiment of the present invention in direct communication between devices in a wireless network.

The memory unit 1330 stores or extracts various data necessary for allocating discovery resources to the terminal according to an embodiment of the present invention in direct communication between devices in a wireless network.

The control unit 1310 allocates discovery resources by a dynamic allocation method or a semi-persistent allocation method according to an embodiment of the present invention in direct communication between devices in a wireless network.

When assigning RBs for transmitting discovery information to a terminal, the controller 1310 can dynamically allocate time or frequency positions of resources to each specific D2D terminal for each subframe. Alternatively, The same time or frequency position can be equally allocated to the subframe.

For resource allocation, the BS allocates a resource region through which the UE transmits / receives on the downlink or uplink through the PDCCH (downlink: FIG. 14, uplink: FIG. This allocation information is delivered using the DCI format in the PDCCH. The base station performs CRC scrambling using the C-RNTI of the transmitting / receiving terminals, and the terminals perform blind decoding of DCI formats using their C-RNTIs. In order to allocate such resources, discovery information must be transmitted to an unspecified number of terminals. At this time, the transmitting terminal reuses the existing C-RNTI, and the receiving terminal needs a new D2D-RNTI.

FIG. 14 shows a frame structure diagram for D2D included in the downlink, and FIG. 15 shows a frame structure diagram for D2D included in the uplink.

The BS allocates a resource area through the PDCCH to be transmitted / received on the downlink as shown in FIG. 14 or on the uplink as shown in FIG.

In FIG. 14, a part of the frame included in the downlink is allocated as a resource for D2D communication allocated through the PDCCH, and a part is allocated for a cellular communication.

In FIG. 15, a part of the area excluding the Physical Uplink Control Channel (PUCCH) 1510 and 1520 is allocated as a resource for D2D communication allocated through the PDCCH, and a part of the area is allocated for the cellular communication Allocate resources.

In order to receive on the uplink and receive on the downlink, it is necessary to modify the new DCI format or the existing DCI formats. The downlink scheduling assignment information is valid for the same subframe in which the signal is transmitted, and the scheduling assignment information is transmitted by selecting one of the DCI formats.

DCI format 1 / 1A / 1B / 1C / 1D / 2 / 2A / 2B is used for downlink allocation and DCI format 3 / 3A is used for uplink power control when DCI format 0 is used for uplink allocation. use. However, it is not limited to this method.

FIG. 16 illustrates a greedy approach in which each mobile station decides a resource to transmit its discovery information in a static allocation method to be compared according to the present invention.

When the D2D terminal knows which subframe (s) in the frame is the discovery subframe (1600) through the SIB information, each D2D terminal must receive the discovery subframe (s) 1600 for a predetermined period of time . When the reception is completed, each D2D terminal transmits a discovery signal. For this purpose, each D2D terminal measures and classifies the energy of the RB constituting the received discovery subframe. At the end of the classification, the discovery information is transmitted in the RB with an energy level of the lower x% (for example: 5%). The structure of the RB 1610 to which the discovery information is transmitted has 12 subcarriers on the frequency axis and 14 symbols on the time axis. In this case, the OFDM symbol has 14 OFDM symbols in the case of OFDM and the 14 SC-FDMA symbols in case of SC-FDMA (Single-Carrier Frequency Division Multiple Access). This static allocation-based greedy approach can not efficiently handle congestion, load balancing, priority handling, or discovery information changes as described above.

In addition, the method and system according to embodiments of the present invention can be implemented as computer-readable codes on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and a carrier wave (for example, transmission via the Internet).

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

Claims (44)

A method of allocating resources in direct communication between devices in a wireless network,
Requesting resource allocation for a resource block for direct communication between devices to a base station;
And receiving a resource allocation for the resource block from the base station,
In the resource allocation process,
And allocating a time or frequency position of the resource block to the resource block. The method according to claim 1,
In the resource allocation process,
Receiving a system information block (SIB) from the base station;
Decoding the SIB; And
And acquiring resource allocation information included in the SIB using an SI-RNTI (System Information-Radio Network Temporary Identifier)
Wherein the SIB is allocated by changing a position of a time or a frequency of the resource block in a predetermined frame or 2-4 sub-frames. The method according to claim 1,
In the resource allocation process,
And allocating the same time or frequency position to the consecutive frames. The method according to claim 2 or 3,
In the resource allocation process,
Receiving a system information block (SIB) from the base station;
Decoding the SIB; And
And acquiring resource allocation information included in the SIB using an SI-RNTI (System Information-Radio Network Temporary Identifier)
Wherein the SIB allocates the same time or frequency position to the allocated or consecutive frames by changing the time or frequency position of the resource block for each predetermined frame or sub-frame. Resource allocation method. A method of allocating resources in direct communication between devices in a wireless network,
Receiving a resource allocation request for a resource block from a terminal;
And allocating resources to the resource block for the resource blocks,
The resource allocation process includes:
And allocating a time or frequency location of the resource block. 6. The method of claim 5,
The resource allocation process includes:
And allocating resources dynamically by changing a position of a time or a frequency of the resource block every frame. 6. The method of claim 5,
The resource allocation process includes:
And assigning the same time or frequency position to the consecutive frames. ≪ RTI ID = 0.0 > 8. < / RTI > 8. The method according to claim 6 or 7,
The resource allocation process includes:
And transmitting the allocated resources to the terminal through the SIB (System Information Block)
Wherein the SIB periodically allocates time or frequency positions of the resource blocks at regular intervals, or positions of the same time or frequency are allocated statically or semi-statically in consecutive frames. A method of resource allocation in direct communication. An apparatus for allocating resources in direct communication between devices in a wireless network,
A resource allocation request for a resource block to a base station and a resource allocation for the resource block from the base station,
Wherein,
Wherein the resource block is allocated a time or frequency location of the resource block. 10. The method of claim 9,
Wherein,
Wherein the resource blocks are dynamically allocated by changing positions of time or frequency of the resource blocks in every frame. 10. The method of claim 9,
Wherein,
And the same time or frequency position is assigned to the consecutive frames. The method according to claim 10 or 11,
Wherein,
Receiving a SIB (System Information Block) from the base station, decoding the SIB, and acquiring resource allocation information included in the SIB using an SI-RNTI (System Information-Radio Network Temporary Identifier)
Wherein the SIB is assigned a static or semi-statically allocated time or frequency position of the resource block at a predetermined period of time, or a position of the same time or frequency is assigned to consecutive frames in a direct communication between devices in a wireless network / RTI > An apparatus for allocating resources in direct communication between devices in a wireless network,
And a controller for receiving a resource allocation request for a resource block from the terminal and allocating resources to the resource block for the resource block,
Wherein,
And allocating a time or frequency location of the resource block. 14. The method of claim 13,
Wherein,
And allocates resources dynamically by changing a time or a frequency position of the resource block every frame. 14. The method of claim 13,
Wherein,
And assigning the same time or frequency position to the consecutive frames. ≪ RTI ID = 0.0 > 8. < / RTI > 16. The method according to claim 14 or 15,
Wherein,
And transmitting the allocated resources to the terminal through the SIB (System Information Block)
Wherein the SIB allocates the same time or frequency position to the allocated or consecutive frames by changing the time or frequency position of the resource block for each predetermined frame or sub-frame. Resource allocation device. A method of requesting resource allocation in direct communication between devices in a wireless network,
Acquiring information on a resource block through the received SIB;
Scanning an energy level for the resource block;
Determining whether a predetermined condition is satisfied as a result of the scanning;
And requesting a dynamic resource allocation to the base station when the predetermined condition is satisfied. 18. The method of claim 17,
The predetermined condition is that,
When the energy level of all the resource blocks is higher than the specific threshold value, and there is no resource block whose energy level is lower than the specific threshold value, there is a resource block whose energy level is lower than the specific threshold value, And a case where the number of resource blocks whose energy level is lower than a specific threshold is equal to or less than a specific number when the resource level is lower than a predetermined threshold. 18. The method of claim 17,
The predetermined condition is that,
And the energy level of all the resource blocks is higher than a specific threshold in the process of participating in the discovery by the terminals whose priority is higher than a specific value. 18. The method of claim 17,
The predetermined condition is that,
In a direct communication between devices in a wireless network, it is determined that the energy level is lower than a certain threshold value in the process of participating in the discovery by the terminals whose priority is higher than a certain value, but the case where the amount of discovery information changes and additional resource allocation is required . A method of allocating resources in direct communication between devices in a wireless network,
Receiving a dynamic resource allocation request from a terminal to a base station when a predetermined condition is satisfied,
The terminal may acquire information on a resource block through a received SIB (system information block), scan an energy level of the resource block, and determine whether a predetermined condition is satisfied as a result of scanning. Wherein the method comprises the steps of: 22. The method of claim 21,
The predetermined condition is that,
When the energy level of all the resource blocks is higher than the specific threshold value, and there is no resource block whose energy level is lower than the specific threshold value, there is a resource block whose energy level is lower than the specific threshold value, And a case where the number of resource blocks whose energy level is lower than a specific threshold is equal to or less than a specific number when the resource level is lower than a predetermined threshold. 22. The method of claim 21,
The predetermined condition is that,
And the energy level of all the resource blocks is higher than a specific threshold in the process of participating in the discovery by the terminals whose priority is higher than a specific value. 22. The method of claim 21,
The predetermined condition is that,
In a direct communication between devices in a wireless network, it is determined that the energy level is lower than a certain threshold value in the process of participating in the discovery by the terminals whose priority is higher than a certain value, but the case where the amount of discovery information changes and additional resource allocation is required . An apparatus for allocating resources in direct communication between devices in a wireless network,
Acquires information on a resource block through a received SIB (System Information Block), scans an energy level of the resource block, and determines whether a predetermined condition is satisfied as a result of the scanning. If the predetermined condition is satisfied And a controller for requesting a dynamic resource allocation to the base station. 26. The method of claim 25,
The predetermined condition is that,
When the energy level of all the resource blocks is higher than the specific threshold value, and there is no resource block whose energy level is lower than the specific threshold value, there is a resource block whose energy level is lower than the specific threshold value, And a case where the number of resource blocks whose energy level is lower than a specific threshold is equal to or less than a specific number when there is no margin in the wireless network. 26. The method of claim 25,
The predetermined condition is that,
And the energy level of all the resource blocks is higher than a specific threshold in the process of participating in the discovery by the terminals having the priority higher than the specific value. 26. The method of claim 25,
The predetermined condition is that,
In a direct communication between devices in a wireless network, it is determined that the energy level is lower than a certain threshold value in the process of participating in the discovery by the terminals whose priority is higher than a certain value, but the case where the amount of discovery information changes and additional resource allocation is required / RTI > An apparatus for allocating resources in direct communication between devices in a wireless network,
And a controller for receiving a dynamic resource allocation request from the terminal to the base station when the predetermined condition is satisfied,
The terminal may acquire information on a resource block through a received SIB (system information block), scan an energy level of the resource block, and determine whether a predetermined condition is satisfied as a result of scanning. Wherein the resources are allocated to the plurality of devices. 30. The method of claim 29,
The predetermined condition is that,
When the energy level of all the resource blocks is higher than the specific threshold value, and there is no resource block whose energy level is lower than the specific threshold value, there is a resource block whose energy level is lower than the specific threshold value, And a case where the number of resource blocks whose energy level is lower than a specific threshold is equal to or less than a specific number when there is no margin in the wireless network. 30. The method of claim 29,
The predetermined condition is that,
And the energy level of all the resource blocks is higher than a specific threshold in the process of participating in the discovery by the terminals having the priority higher than the specific value. 30. The method of claim 29,
The predetermined condition is that,
In a direct communication between devices in a wireless network, it is determined that the energy level is lower than a certain threshold value in the process of participating in the discovery by the terminals whose priority is higher than a certain value, but the case where the amount of discovery information changes and additional resource allocation is required / RTI > A method of allocating resources in direct communication between devices in a wireless network,
Transmitting a resource allocation request to a base station;
Receiving a physical downlink control channel (PDCCH) from the base station;
Acquiring resource block information for transmitting a search signal through the PDCCH; And
And transmitting the resource block information from the resource corresponding to the resource block information. 34. The method of claim 33,
Wherein the terminal that has not transmitted the search signal receives all the resources corresponding to the corresponding resource region information to which the search signal is transmitted through the SIB (System Information Block). . 34. The method of claim 33,
Wherein the PDCCH includes resource block information to be transmitted / received in one of a downlink and an uplink. A method of allocating resources in direct communication between devices in a wireless network,
Receiving a resource allocation request from a terminal;
Transmitting a Physical Downlink Control Channel (PDCCH) to the UE; And
And receiving data from a resource corresponding to the resource block information included in the PDCCH. 37. The method of claim 36,
Wherein the terminal that has not transmitted the search signal receives all the resources corresponding to the corresponding resource region information to which the search signal is transmitted through the SIB (System Information Block). . 37. The method of claim 36,
Wherein the PDCCH includes resource block information to be transmitted / received in one of a downlink and an uplink. An apparatus for allocating resources in direct communication between devices in a wireless network,
A receiver for receiving a resource allocation request from a terminal; And
And a transmitter for transmitting a Physical Downlink Control Channel (PDCCH) to the UE,
Wherein the receiver is further configured to receive data from a resource corresponding to the resource block information included in the PDCCH. 40. The method of claim 39,
Wherein the terminal that has not transmitted the search signal receives all the resources corresponding to the corresponding resource region information to which the search signal is transmitted through the SIB (System Information Block). . 40. The method of claim 39,
Wherein the PDCCH includes resource block information to be transmitted / received in one of a downlink and an uplink. An apparatus for allocating resources in direct communication between devices in a wireless network,
A receiver for receiving a resource allocation request from a terminal; And
And a transmitter for transmitting a Physical Downlink Control Channel (PDCCH) to the UE,
Wherein the receiving unit receives data from a resource corresponding to the resource block information,
Wherein the PDCCH includes resource block information for a search signal transmission. 43. The method of claim 42,
Wherein the terminal that has not transmitted the search signal receives all the resources corresponding to the corresponding resource region information to which the search signal is transmitted through the SIB (System Information Block). . 43. The method of claim 42,
Wherein the PDCCH includes resource block information to be transmitted / received in one of a downlink and an uplink.

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