KR102049047B1 - Method of data transmitting and receiving in the talk-around direct communication network - Google Patents

Abstract

Determining a data frame to which data is to be transmitted, requesting a reservation of a data transmission section included in the data frame in a transmission request section included in the data frame, and receiving a response signal transmitted in the transmission response section included in the data frame And transmitting data by a transmitting terminal included in the terminal-to-terminal direct communication network including analyzing the response signal and transmitting data through the data transmission interval, and a data frame in the transmission request interval included in the data frame. Receiving a request signal for requesting the reservation of the data transmission section contained in the, Broadcasting a response signal in the transmission response section included in the data frame, Signal field of a plurality of data slots included in the data transmission section ) And link identifiers among multiple data slots match A method for receiving data is provided by a receiving terminal included in an inter-terminal direct communication network comprising identifying a first data slot used by a terminal, and receiving data in the first data slot.

Description

{Method of data transmitting and receiving in the talk-around direct communication network}

The present invention relates to a method in which each terminal included in a terminal-to-terminal direct communication network transmits and receives data using a data frame.

Conventional distributed resource allocation may use carrier sense multiple access with collision detection (CSMA / CD) scheme of IEEE 802.11. In the CSMA / CD method, when a channel is in an idle state, each UE requests a resource through a request to send / clear to send (RTS / CTS) message procedure, and a response is received without collision. In this case, data can be transmitted by occupying radio resources. At this time, even if two or more terminals transmit the RTS message at the same time, the counterpart terminal which does not detect this cannot transmit the CTS message.

On the other hand, distributed resource allocation also allocates a wireless section in a form suitable for packet-based data transmission. In this case, the radio section according to a form suitable for packet-based data transmission is used to transmit one packet transmission or data slot.

The above resource allocation method is not suitable for supporting the quality of service (QoS) of the voice or large file and the QoS of the interactive service.

An object of the present invention is to provide a distributed resource allocation method suitable for a service for direct communication requiring various QoS such as voice or large file transfer QoS or bidirectional service QoS.

According to an embodiment of the present invention, a method for transmitting data by a transmitting terminal included in an inter-terminal direct communication network is provided. The data transmission method may include determining a data frame to transmit data, requesting a reservation of a data transmission interval included in the data frame in a transmission request interval included in the data frame, and in a transmission response interval included in the data frame. Receiving the transmitted response signal, and analyzing the response signal to transmit data through the data transmission interval.

The data transmission method may further include transmitting a link establishment request message before determining, and receiving a link establishment response message in response to the link establishment request message to obtain a link identifier.

The determining of the data transmission method may include determining a data frame according to an orthogonal frequency division multiplexing (OFDM) scheme, and the data frame may be configured to receive an ACK signal for data transmitted in the data transmission interval. It includes an ACK channel for transmitting and receiving, the data transmission interval may include a plurality of data slots.

The determining of the data transmission method may include determining one data channel among a plurality of data channels included in the data frame according to an orthogonal frequency division multiple access (OFDMA) scheme. The frame may include an ACK channel for transmitting and receiving an ACK signal for data transmitted in the data transmission interval, and the data transmission interval may include a plurality of data slots.

The determining of the data channel in the data transmission method may include scheduling priority of the transmitting terminal based on a function of an identifier of the transmitting terminal, a link identifier between direct communication terminals, a time identifier, a data QoS index, and a resource load index. , Calculating the SP), and selecting a data channel including the SP of the transmitting terminal from among the plurality of data channels.

The requesting in the data transmission method may include transmitting a resource request signal by using a radio resource corresponding to an SP of a transmitting terminal among radio resources included in a transmission request interval.

The transmitting of the data transmission method may include: analyzing an SP corresponding to at least one radio resource in which a response signal is received, determining a rank of an SP of a transmitting terminal, and corresponding to a determined rank among a plurality of data slots. The method may include transmitting data using one data slot.

The transmitting in the data transmission method may further include broadcasting a transmission indicator signal by using a radio resource corresponding to the SP of the transmitting terminal in the transmission indicator section after the first data slot when the data transmission is completed. can do.

After transmitting in the data transmission method, the method may further include receiving an ACK signal in a first ACK slot corresponding to a first data slot among a plurality of ACK slots included in an ACK channel.

The transmitting of the data transmission method may include transmitting a preamble of a reservation type in a first data slot and transmitting a periodic allocation (PA) request message requesting periodic reservation of a data slot in the first data slot. And receiving the ACK signal, receiving the PA ACK signal indicated by the identifier corresponding to the resource reservation type to the PA in the first ACK slot, and after receiving the PA ACK signal, The method may further include using the first data slot included in the next data frame of the data frame as the PA reserved data slot.

The transmitting of the data transmission method may include: transmitting a preamble of a reservation type in a first eater slot, and transmitting a continuous allocation (CA) request message requesting continuous reservation of a data slot in the first eater slot. And receiving the ACK signal, receiving the CA ACK signal indicated by the identifier corresponding to the CA as the resource reservation type in the first ACK slot, and after receiving the CA ACK signal, The method may further include using, from the first data slot included in the second data frame that is the next data frame of the data frame to the last data slot, as the CA reserved data slot.

The data transmission method includes a third data frame that is a next data frame of a second data frame after using the first data slot included in the next data frame of the data frame to the last data slot as a CA reserved data slot. In case of continuously reserving all the data slots, the method may further include, after using the last data slot of the second data frame, broadcasting a transmission indicator signal by using a radio resource corresponding to the SP of the transmitting terminal.

According to another embodiment of the present invention, a method for receiving data by a receiving terminal included in a terminal-to-terminal direct communication network is provided. The data receiving method includes receiving a request signal for requesting a reservation of a data transmission section included in a data frame in a transmission request section included in a data frame, and broadcasting a response signal in a transmission response section included in the data frame. Receiving a signal field of a plurality of data slots included in a data transmission interval, identifying a first data slot used by a terminal having a matching link identifier among the plurality of data slots, and in the first data slot Receiving the data.

According to another embodiment of the present invention, a method for receiving data by a receiving terminal included in a terminal-to-terminal direct communication network is provided. The data receiving method includes receiving a request signal for requesting a reservation of a data transmission section included in a data frame from at least one transmitting terminal in a transmission request section included in a data frame, an allocation type (AT) region And determining a transmitting terminal to transmit a response signal among at least one transmitting terminal by dividing the request signal into a scheduling priority (SP) region, and transmitting the response signal to the transmitting terminal determined in the transmission response interval included in the data frame. And transmitting the data transmitted by the determined transmitting terminal in the data transmission interval.

The determining of the data receiving method may include determining a priority of at least one transmitting terminal based on a signal received in an AT area, and transmitting a response signal to the transmitting terminal having the highest priority among the at least one transmitting terminal. The method may include determining a transmission terminal to be transmitted.

The transmitting of the response signal in the data receiving method may include transmitting the response signal to the determined transmission terminal using the radio resource used in the determined transmission terminal.

The determining of the data receiving method may include determining a priority of at least one transmitting terminal based on a signal received in the SP region when there is no signal received in the AT region, and among the at least one transmitting terminal. And determining a transmission terminal having the highest rank as the transmission terminal to which the response signal is to be transmitted.

The transmitting of the response signal in the data receiving method may include transmitting the response signal to a terminal transmitting a signal in the SP region by using a radio resource used in the SP region.

After receiving data in the data receiving method, the method may further include transmitting an ACK signal for the received data using a radio resource included in a transmission response period included in a next data frame of the data frame. .

As described above, according to an embodiment of the present invention, the reliability of the direct communication between the terminals can be improved by preventing the collision of the message transmitted from the terminal included in the direct communication network between the terminals. In addition, by providing various types of resource reservation types, it is possible to guarantee various types of QoS in a distributed inter-terminal direct communication network.

1 is a flowchart illustrating a link establishment process between terminals according to an embodiment of the present invention.
2 is a diagram illustrating a plurality of terminals in which a link is established through the link setting procedure of FIG. 1.
3 is a diagram illustrating a data resource for transmitting data between two terminals according to an embodiment of the present invention.
4 is a diagram illustrating divided data resources according to a frequency division method according to an embodiment of the present invention.
5 is a diagram illustrating a scheduling code according to an embodiment of the present invention.
6 is a diagram illustrating a data frame of general allocation according to an embodiment of the present invention.
7 illustrates a data frame of periodic allocation according to an embodiment of the present invention.
8 is a flowchart illustrating a distributed resource allocation procedure according to an embodiment of the present invention.
9 is a diagram illustrating a data frame of base station allocation over time according to an embodiment of the present invention.
FIG. 10 is a diagram illustrating a data frame of periodic allocation over time according to an embodiment of the present invention. FIG.
FIG. 11 is a diagram illustrating a data frame of consecutive allocation according to an embodiment of the present invention.
12 illustrates a data frame of mixed allocation according to an embodiment of the present invention over time.
13 illustrates an OFDM data frame according to another embodiment of the present invention.
14 illustrates an OFDMA data frame according to another embodiment of the present invention.
15 is a diagram illustrating a data channel according to scheduling priority according to another embodiment of the present invention.
16 illustrates an OFDMA data frame according to another embodiment of the present invention.
17 is a flowchart illustrating a distribution based resource allocation process according to another embodiment of the present invention.
18 illustrates a direct communication network and a data frame according to another embodiment of the present invention.
19 illustrates a method of periodically allocating a data frame according to another embodiment of the present invention.
20 and 21 illustrate a method of continuously allocating data frames according to another embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, a terminal may be a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), a high reliability mobile station (HR-MS). May also refer to a subscriber station (SS), a portable subscriber station (PSS), an access terminal (AT), a user equipment (UE), and the like. It may also include all or part of the functionality of the HR-MS, SS, PSS, AT, UE and the like.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, “block”, etc. described in the specification mean a unit that processes at least one function or operation, which is hardware or software or a combination of hardware and software. It can be implemented as.

1 is a flowchart illustrating a link establishment process between terminals according to an embodiment of the present invention.

Referring to FIG. 1, a terminal identifying a terminal to attempt communication may perform a link establishment procedure. The link setup procedure is started by a terminal (transmitting terminal) 110 to transmit data, by sending a link setup request message.

Upon receiving the link setup request message, the terminal (receiving terminal) 120 transmits a link setup response message to the transmitting terminal in response thereto.

In this case, the link establishment request message includes an address of the transmitting terminal 110 and the receiving terminal 120 and a link identifier (Link ID) between the two terminals. In addition, the two terminals may perform QoS parameter and basic function negotiation related to a data service transmitted through a corresponding link through link establishment request / response messaging.

A terminal capable of performing a base station or controller function may relay a link establishment procedure between terminals. In this case, the link identifier may be assigned at a terminal that performs a base station or a controller function.

FIG. 2 is a diagram illustrating a plurality of terminals in which a link is established through the link setting procedure of FIG. 1.

Referring to FIG. 2, a link is established between the terminal 1 201 and the terminal 2 202, a link is established between the terminal 3 203 and the terminal 4 204, and the terminal 5 205 and the terminal 6. A link was established between 206.

3 is a diagram illustrating a data resource for transmitting data between two terminals according to an embodiment of the present invention.

When the link setting between the transmitting terminal and the receiving terminal is completed, the transmitting terminal performs a procedure for transmitting data. In order to transmit data to a receiving terminal, the transmitting terminal may acquire a transmission resource through distributed based scheduling.

In one data resource 300 according to an embodiment of the present invention, when rate scheduling is not performed (without rate scheduling), a transmission request (distributed scheduling request, DS_REQ) section 301, and a transmission response It may include a distributed scheduling response (DS_RSP) section 302 and a data transmission section 303. Alternatively, the data resource 310 when the rate is scheduled may include a transmission request / response (DS_REQ / DS_RSP) section 311 and 312, a pilot transmission section 313, and channel quality information (CQI). The interval 314 and the data transmission interval 315 may be included.

Referring to FIG. 3, transmission signals of the DS_REQ section 301 and the DS_RSP section 302 are determined according to values of a scheduling code SC. In this case, the SC may identify a link established between the terminals and determine a scheduling priority (SP) and a resource allocation type (AT). That is, the terminal may distinguish the requests of the plurality of terminals by using the signals received in the DS_REQ section 301 and the DS_RSP section 302, and identify the priority and allocation form of the request. At this time, each terminal may identify the subject, the occupancy period or whether the occupancy of the resource and the like through the AT.

The AT of the DS_REQ section 301 and the DS_RSP section 302 includes a base station allocation (BA), periodic allocation (PA), and continuous allocation (CA). BA is the highest priority. PA indicates that resources are used periodically. The CA indicates that the resource is used continuously and has a lower priority than the BA and PA, so that if a BA or PA occurs in the middle of the CA, it yields the resource. What does not correspond to the allocation form of any one of the BA, PA and CA is normal allocation (None), which means that one data resource is allocated once. AT's priority is BA> PA> CA> None.

The SP may be calculated through a function of a source (sending) terminal identifier, an inter-terminal link identifier, a time identifier, a data QoS index, and a resource load index.

In this case, the range of the SP may be limited to the remaining areas except the AT area in the range of the SC, and the SP may indicate the priority of scheduling. For example, a smaller value of SP may have a higher priority. When a link is established between two terminals, the scheduling priority may be changed according to a time index (for example, a frame index) in order to prevent continuous collision of the SP. The two UEs that establish the link may share the same value as an emergency index and a congestion index. For example, each terminal may transmit and receive an emergency index and a congestion index in a link configuration, a traffic connection configuration, or a data transmission interval.

The emergency index is an index related to the maximum transmission delay of data to be transmitted. The emergency index increases as the QoS for the transmission delay of the data service increases. The congestion index is an index representing the frequency of use or request of distributed resources. The congestion index has a higher value as a load on distributed resources increases. The emergency and congestion indexes can be used to determine the SP window (from the maximum to the minimum of the scheduling priority allowed by the current link).

4 is a diagram illustrating divided data resources according to a frequency division method according to an embodiment of the present invention.

 Each data frame 401 or 411 may be based on orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA). That is, each terminal uses (400) the entire data frame 401 as a data resource 402 according to the OFDM scheme, or one of a plurality of data resources included in one data frame 411 according to the OFDMA scheme. May use 410 data resources 412.

5 is a diagram illustrating a scheduling code according to an embodiment of the present invention.

Distributed-based scheduling of terminal-to-terminal communication should allocate resources to increase the utilization of radio resources and support QoS of direct communication services. That is, according to an embodiment of the present invention, the media access control (MAC) of each link may be configured so that a terminal performing communication between terminals may allocate and reserve radio resources in consideration of priority and priority. In the layer, SP and AT are defined. The SP is transmitted in the procedure intervals DS_REQ and DS_RSP of distributed scheduling for transmitting data. That is, several terminals performing terminal-to-terminal communication may simultaneously request resources for data transmission. Each terminal may identify a resource request through the SP and identify a priority and a resource allocation form of the request. In this case, it is assumed that a signal transmitted in a procedure section of distributed scheduling does not collide.

When a link is established between two terminals wishing to communicate, the two terminals share a link identifier (ID) of the established link. In this case, since link identifiers are set so as not to interfere with each other, the transmitting and receiving terminals may acquire each other's information without transmitting each other's addresses. The SPs of the two terminals may be calculated through a function of a link identifier and a time identifier (eg, frame index). At this time, the scheduling priority may be changed according to the time identifier so as to match the fairness between the terminals.

Referring to FIG. 5, the scheduling code 501 includes an AT area and an SP area. The AT region includes resources corresponding to BA, PA, and CA, and the terminal may identify a resource allocation type through a signal transmitted using each resource. The SP region is composed of a plurality of radio resources and may be divided by the number of SPs allowed in the data frame.

When the scheduling priority of the corresponding link is determined, each terminal transmits a signal using a resource region corresponding to the determined priority. At this time, if two terminals have the same (priority) value at the same time point and the SP area is sufficiently larger than the number of activated links, the two terminals may transmit a request / response signal without collision with another link.

Referring to FIG. 5, when the frame used by the terminal is changed from K 502 to K + n 503, the resource of the SP region is changed, and when the link is different (504), the resource of the SP region is also changed. In addition, in the case of periodic resource allocation (505), a signal is transmitted using one of a resource corresponding to the PA of the AT and one of the SP regions.

6 is a diagram illustrating a data frame of general allocation according to an embodiment of the present invention.

Referring to FIG. 6, there is no signal (BA, PA, or CA request signal) transmitted through the AT region in the DS_REQ section, and the first signal 601, the second signal 602, and three portions of the SP region, respectively. The third signal 603 is transmitted. The receiving terminal transmits a response signal to the transmitting terminal that transmitted each signal in the DS_RSP section.

In an embodiment of the present invention, the priority of the first signal 601 is the highest since the priority of the portion closer to the AT region among the three portions of the SP region is higher. Accordingly, the terminal transmitting the first signal 601 may transmit data using the data transmission section 604.

7 illustrates a data frame of periodic allocation according to an embodiment of the present invention.

Referring to FIG. 7, signals are transmitted in the PA region 701 of the AT region and in three portions (first to third signals) 702, 703, and 704 of the AT region because they are data frames of periodic allocation. . In this case, the terminal requesting the PA transmits signals in the PA region and the SP region (PA request signal and second signal) (701 and 703), and the receiving terminal is the same as the radio resource where the second signal is transmitted in the DS_RSP section. Transmit signal using radio resources. That is, although the priority of the first signal 702 among the signals received in the SP region of the DS_REQ interval is higher than the priority of the remaining signals, the terminal requesting the PA transmits the second signal 703, so that the receiving terminal receives the DS_RSP interval. Transmits a signal to a PA requesting terminal using the same radio resource as the second signal 703. The PA requesting terminal may transmit data in a subsequent data transmission section 705.

8 is a flowchart illustrating a distributed resource allocation procedure according to an embodiment of the present invention.

Referring to FIG. 8, a terminal (hereinafter, referred to as a “transmitting terminal”) requesting a data resource among a plurality of terminals connected by a link transmits a resource request signal by using a resource corresponding to its SC in a DS_REQ section. (S801). In this case, the transmitting terminal may request a PA or CA using the AT region included in the DS_REQ section.

Thereafter, the terminal receiving the resource request signal in the DS_REQ section (hereinafter referred to as a "receiving terminal") checks whether there is a signal received in the AT region (S802). If there is a signal received in the AT area, the priority of the AT area is compared to determine the transmitting terminal that has requested the highest priority allocation type (S803). Then, the response signal is transmitted in the DS_RSP section by using the same radio resource as the radio resource used by the determined transmission terminal (S804 and S806). For example, if the receiving terminal receives the PA request and the CA request in the AT area, since the PA request has a higher priority, the receiving terminal uses the same radio resource as the radio resource used by the terminal requesting the PA in the DS_RSP interval. Send a response signal.

On the other hand, if there is no signal received in the AT area, the receiving terminal transmits the signal in the DS_RSP period by using the same radio resource as the radio resource used in the signal received in the DS_REQ period (S805) (S806).

Thereafter, the transmitting terminal that receives the signal transmitted by the receiving terminal in the DS_RSP interval determines whether a signal of a terminal higher than its priority is received (S807), and if not, transmits the packet in the data transmission interval (S808).

Thereafter, the receiving terminal receiving the packet transmitted in the data transmission interval broadcasts an ACK signal by using the radio resource of the DS_RSP interval of the next data frame (S809).

Hereinafter, a resource allocation method according to an embodiment of the present invention will be described with five data frames consecutively arranged as time passes in FIGS. 9 to 12.

9 is a diagram illustrating a data frame of base station allocation over time according to an embodiment of the present invention.

Referring to FIG. 9, in the DS_REQ 911 of the first data frame 910, the base station requests base station allocation, selects one of the resources in the SP region, and transmits a signal. At this time, the other terminal also transmits a signal using resources in the SP region.

Since the receiving terminal receives the BA request in the AT region of the DS_REQ interval, the receiving terminal responds only to the signal for the BA request in the DS_RSP interval 912 and ignores the signal transmitted from the other terminal.

Thereafter, the base station relays the packet using the data transmission interval of the first data frame 910. The receiving terminal transmits an ACK for packet transmission of the first data frame to the base station through the DS_RSP section 922 of the second data frame 920.

In the second data frame 920, the third data frame 930, and the fifth data frame 950, since there is no allocation type requested in the AT region, a plurality of terminals requesting resources transmit data according to a general allocation scheme. The packet can be transmitted by occupying the interval.

FIG. 10 is a diagram illustrating a data frame of periodic allocation over time according to an embodiment of the present invention. FIG.

Referring to FIG. 10, if it is determined that the first terminal that uses the data transmission interval through the general allocation method needs to periodically transmit a packet, the PA is transmitted in the data transmission interval 1013 of the first data frame 1010. Ask. That is, the PA requesting terminal requests periodic resource allocation through the data transmission interval 1013. At this time, the request message may include an occupancy period of the data transmission interval, and the period 1060 may be displayed in units of the number of data frames.

Thereafter, the receiving terminal that transmits the ACK signal to the PA requesting terminal in the DS_RSP section 1022 of the second data frame 1020 knows that the PA has been requested, and the data transmission section 1053 of the fifth data frame 1050 is received. Assign to the first terminal. At this time, if a PA signal is received from the first terminal in the AT region of the DS_REQ 1051, the request signal received from another terminal is ignored, and a response signal is transmitted from the AT region and the SP region of the DS_RSP 1052 to the first terminal. do.

In FIG. 10, the PA requesting terminal sets the period to four data frames, and the PA requesting terminal requesting the PA in the data transmission section 1013 of the first data frame 1010 subsequently transmits the data transmission section in the fifth data frame 1050. (1053) can be occupied.

FIG. 11 is a diagram illustrating a data frame of consecutive allocation according to an embodiment of the present invention.

Referring to FIG. 11, when it is determined that the second terminal, which has used the data transmission interval through the general allocation method, needs to continuously transmit a packet, the second terminal may transmit the data transmission interval (the first data frame 1110). 1113 request a CA. That is, the CA requesting terminal requests continuous resource allocation through the data transmission section 1113. In this case, the request message may include a continuous occupation period of the data transmission interval, and the period 1160 may be displayed in units of the number of data frames.

Thereafter, the receiving terminal transmitting the ACK signal for the data transmission section 1113 of the first data frame 1110 in the DS_RSP section 1122 of the second data frame 1120 transmits data of the third data frame 1130. From the interval 1133, the allocation is continuously performed to the second terminal. That is, if there is no request for a higher allocation type than the CA while the second terminal uses the data transmission interval to the CA, the data transmission interval is continuously allocated to the second terminal.

12 illustrates a data frame of mixed allocation according to an embodiment of the present invention over time.

Referring to FIG. 12, a second terminal using a data transmission interval through a general allocation method requests a CA in the data transmission interval 1213 of the first data frame 1210 as needed and the second data frame 1220. An ACK signal was received from the DS_RSP 1222. However, since the first terminal requests the PA in the data transmission interval of the second data frame, the first terminal uses the data transmission interval 1253 in the data frame (the fifth data frame) 1250 of the next period 1260. . In addition, since a BA is requested in the DS_REQ 1231 of the third data frame 1230, the data transmission interval 1233 of the third data frame 1230 may be allocated to the base station. The second terminal may use the data transmission interval 1243 of the remaining data frame (fourth data frame) 1240.

In another embodiment of the present invention, it is assumed that there are 112 link identifiers included in the direct communication network between terminals. In this case, the link identifier is 0 to 111.

13 illustrates an OFDM data frame according to another embodiment of the present invention.

Referring to FIG. 13, the duration of an OFDM data frame 1300 according to an embodiment of the present invention is 5 ms and a bandwidth is 10 MHz. In this case, a bandwidth of 10 MHz is divided by the number of link identifiers (112 in the embodiment of the present invention), and one SP is allocated to the divided area. Each link is given one SP among a plurality of SPs, and frequencies corresponding to each SP are orthogonal to each other.

When a plurality of terminals transmit a signal (or transmit an SP) using a resource corresponding to the SP in the DS_REQ period 1311 of the OFDM data frame 1300, the order of using the data slot according to the priority of the transmitted signal Is determined. In this case, the OFDM data frame 1300 includes three data slots 1321, 1322, and 1323.

For example, when signals are transmitted in SP 2, 50 SP, SP 73 and SP 111 of the DS_REQ section 1311 of the first OFDM data frame 1300, the SPs 2 and 50 in the order of priority are transmitted. The SP SP and the UE of SP 73 may transmit data using data slots, and the UE of SP 111 cannot transmit signals using the first OFDM data frame 1300. At this time, the terminal of the SP 2 can transmit a signal using the data slot 1321, the terminal of SP 50, can transmit a signal using the data slot 1322, SP 73 The terminal may transmit a signal using the second data slot 1323.

In the ACK channel included in the OFDM data frame 1300, an ACK signal for each data slot is transmitted and received. In the OFDM data frame 1300 according to an embodiment of the present invention, the ACK channel includes three ACK slots 1331, 1332, and 1333 corresponding to each data slot one-to-one, and an ACK signal is transmitted and received in each ACK slot.

14 illustrates an OFDMA data frame according to another embodiment of the present invention.

Referring to FIG. 14, an OFDMA data frame 1400 may also use frequency resources divided into a plurality of data channels 1410. An OFDMA data frame according to an embodiment of the present invention includes a plurality of ACK slots that correspond one-to-one to a DS_REQ and DS_RSP interval 1420, a data transmission resource 1430, and each data slot 1431 included in the data transmission interval. An ACK channel 1440 is included, and a transmission indicator (TI) 1432 is inserted between each data slot 1431.

In one embodiment of the present invention, OFDMA data frame 1400 may include 16 data channels 1410, and the duration of OFDMA data frame 1400 may be 15 ms or 20 ms. A 15ms OFDMA data frame may include four data slots for each data channel, and a 20ms OFDMA data frame may include six data slots for each data channel. In the following embodiment, the present invention is described using a 15ms OFDMA data frame.

15 is a diagram illustrating a data channel according to scheduling priority according to another embodiment of the present invention.

A terminal according to an embodiment of the present invention may determine a data channel to use according to the SP. That is, when the terminal determines the SP according to Equation 1, one data channel to be used by the terminal is determined among the plurality of data channels included in the OFDMA data frame (16 in the case of 15 ms OFDMA data frame). For example, as shown in FIG. 15, when the SPs are filled with zigzag in 16 data channels, 0, 31, 32, 63, 64, 95, and 96 SPs are allocated to the 0 data channel, and 15 is allocated to the 15 data channel. SPs 16, 47, 48, 79, 80, and 111 may be allocated. In an embodiment of the present invention, since there are 112 links included in the direct communication network, seven terminal pairs in each data channel may request data transmission resources in the DS_REQ interval without colliding with each other.

 16 illustrates an OFDMA data frame according to another embodiment of the present invention.

Referring to FIG. 16, some of the seven terminals allocated to the data channel x may request resources in the DS_REQ interval 1611, receive a response in the DS_RSP interval 1612, and then use the data slot 1622. The terminal transmits the data, and the terminal transmitting the data broadcasts its own SP using the TI section 1623. After data is transmitted in the last data slot included in the data transmission resource, the terminal receiving the data transmits the ACK signals in the order of the terminals transmitting the data using the ACK channel 1630. For example, if three of the seven terminals request a resource in the DS_REQ interval 1611, the terminal 0 having the highest SP transmits data using the data slot 0 and then its own in the next TI interval. Broadcast the SP. Thereafter, the first terminal with the next highest SP transmits data using the first data slot, and then broadcasts its own SP in the next TI interval, followed by the second terminal with the lowest SP, the second data slot. Send data using. That is, after the terminal having a higher SP than all transmit data, the next data slot can be used by itself.

Then, after the third data slot passes, each terminal that receives the data transmitted by terminals 1 to 3 transmits an ACK signal to terminals 0, 1, and 2 in the ACK channel 1630.

17 is a flowchart illustrating a distribution based resource allocation process according to another embodiment of the present invention.

Referring to FIG. 17, first, a terminal continuously senses a data slot and an ACK channel (1701). Next, when data to be transmitted is generated, a data slot in which the resource is not reserved is searched for 1702, and the data slot in which the resource is reserved is not used. In the embodiment of the present invention, the reserved resource means that a specific terminal is allocated to a data channel by a PA or a CA. In an embodiment of the present invention, each terminal identifies a pattern of a preamble located at the beginning of a data slot, or recognizes an identifier (eg, a specific code, a specific field, or a resource reservation type field) of an ACK channel. It may be determined whether a resource of a data channel is reserved.

Thereafter, the transmitting terminal for transmitting data transmits a resource request signal using a radio resource corresponding to its SP in the DS_REQ section (1703). The terminal to receive data (the terminal in the reception mode) receives a signal in the DS_REQ section. At this time, it is checked whether the signal transmitted from the terminal with which the link identifier is identical (corresponding to its SP) is transmitted (S1704). When the signal transmitted from the terminal with the identical link identifier is received, the corresponding SP is corresponded to in the DS_RSP interval. The response signal is broadcast using a radio resource (1705).

Thereafter, the transmitting terminal receives all signals in the DS_RSP interval, and when a response signal transmitted using a radio resource corresponding to its SP is received (S1706), the transmitting terminal transmits a packet using data slots in the order of the SPs. (S1707). That is, when the SPs of all response signals of the DS_RSP interval are analyzed and it is determined that the priority of the plurality of terminals requesting the resource is the highest in the DS_REQ interval of the data frame, the packet is transmitted in the 0 data slot. However, if there is a terminal having a higher priority than itself, it waits until the packet transmission of the terminal is completed through the TI signal. When the TI signal indicates that the packet transmission of all the terminals having higher priority than the terminal is completed, the terminal transmits its own packet using the next data slot.

Meanwhile, the receiving terminal that transmits the response signal in the DS_RSP section identifies a data slot used by the terminal whose link identifier matches by receiving a signal field of the data slot, and receives a packet transmitted in the data slot. (S1708).

According to an embodiment of the present disclosure, the transmitting terminal and the receiving terminal may transmit a TI signal corresponding to their priority by using a TI section immediately following a specific data slot. In the case of a 15ms OFDMA data frame, since the number of links included in one data channel is seven, the priority transmitted by the transmitting terminal and the receiving terminal may be one of 0 to 6.

When all data slots included in one data channel are finished, the receiving terminal transmits an ACK signal using an ACK slot corresponding to the data slot received through the ACK channel (S1709). That is, if a specific receiving terminal receives a packet in data slot 0, it transmits an ACK signal through ACK slot 0, and when receiving a packet in data slot 2, it transmits an ACK signal through ACK slot 2.

18 illustrates a direct communication network and a data frame according to another embodiment of the present invention.

Referring to FIG. 18, among terminals included in the direct communication network, terminals A 1801, B 1802, and E 1805 form one network, and terminals C 1803 and D 1804 are one. A network is formed, and terminal C 1803 and E 1805 form one network. At this time, no interference occurs between the networks. That is, terminal A 1801, B 1802, and E 1805 may transmit and receive signals to each other, and terminal C 1803 and D 1804 may also transmit and receive signals to each other, but terminal C 1803 may be used. And the signal transmission / reception area of the D 1804 do not overlap the signal transmission / reception area of the terminal A 1801 and the B 1802. The terminal E 1805 may transmit and receive signals with the terminal A 1801 and the B 1802, and may also transmit and receive signals with the terminal C 1803.

In the network of FIG. 18, each terminal requests a resource according to the SP calculated using the DS_REQ interval 1810. In FIG. 18, it is assumed that the priority of each terminal is terminal A> terminal B> terminal C> terminal D> terminal E.

Next, each terminal receives a response signal from the receiving terminal in the DS_RSP interval 1812, and transmits a packet using data slots (1821, 1822, 1823, 1824). The priority of the terminal B 1802 is higher than the terminal C 1803, but the signal transmission area of the terminal B 1802 overlaps the signal transmission area of the terminal A 1801, and the signal transmission area of the terminal C 1803 is Since the terminal A 1801 does not overlap the signal transmission area of the terminal A 1801, the terminal C 1803 may transmit a packet using the same data slot (data slot 0) 1821 as the terminal A 1801. Thereafter, the terminal A 1801 and the terminal C 1803 transmit priority signals corresponding to their priorities in the next TI period 1822.

Meanwhile, the terminal B 1802 receives the priority signal of the terminal A 1801 in the TI period 1822, and the terminal D 1804 receives the priority signal of the terminal C 18103 in the TI period 1822. Therefore, the terminal B 1802 and the terminal D 1804 transmits the packet using the first data slot 1823. Thereafter, the terminal B 1802 and the terminal D 1804 transmit priority signals corresponding to their priorities in the next TI period 1824.

The terminal E 1805 receives the priority signals of the terminal A 1801 and the terminal C 1803 in the first TI interval 1822, and the terminal B 1802 and the terminal D (in the second TI interval 1824). By receiving the priority signal of 1804, all priority signals are received from the terminal having a higher priority than itself, and the packet is transmitted in the data slot 1825.

19 illustrates a method of periodically allocating a data frame according to another embodiment of the present invention. All data frames of FIG. 19 are data channels x, and the DS_REQ / DS_RSP section is omitted.

Referring to FIG. 19, according to an embodiment of the present invention, a data slot for transmitting a packet through DS_REQ / DS_RSP of a data frame y is determined to four terminals. Subsequently, a transmitting terminal (hereinafter, referred to as a 'PA terminal') to which data slot 1901 is allocated among four terminals uses a preamble of a data slot 1 as a reservation type, and 1 Transmits a PA request message in the first data slot. The receiving terminal receiving the PA request message transmits an ACK signal by indicating the resource reservation type as an identifier corresponding to the PA in the ACK slot 1902 for the first data slot. In an embodiment of the present invention, the identifier corresponding to the PA may be "01", and the period of the PA requested by the PA terminal may be set in data frame units.

Thereafter, data slot 1 of data frame y + N, data frame y + 2N, and data frame y + 3N becomes a data slot reserved for PA. At this time, the PA terminal transmits the preamble of the PA reservation data slot as a reservation type and transmits data using the data slot reserved by the PA. The receiving terminal transmits an ACK signal by indicating a resource reservation type as "01" in the ACK slot for the PA reservation data slot.

Subsequently, if the preamble of the PA reservation data slot is transmitted in a normal type or a signal is not transmitted in the PA reservation data slot, such as data slot 1 of data frame y + 4N, the reservation of the PA resource is cancelled. As such, the receiving terminal returns the resource reservation type back to the normal type. In an embodiment of the present invention, “00” may be used as an identifier indicating a general type of resource reservation type.

20 and 21 illustrate a method of continuously allocating data frames according to another embodiment of the present invention.

If a specific terminal transmits a packet in a general allocation and lacks one data slot, the terminal may continuously use other data slots included in the data frame.

For example, in the network of FIG. 18, it is assumed that terminal A 1801 and terminal D 1804 use two or three data slots to transmit a packet. The terminal A 1801 may use the zero data slot 1821 according to the priority, and then, by continuously configuring the data symbols without the TI interval, up to the first data slot 1823 and the second data slot 182525. Can be used. In this case, since the terminal B 1802 does not receive a valid signal indicating the priority in the TI interval 1822, the data slot 1831 cannot be used, and the terminal A 1801 has a data slot 1825 for the second. Packet can be sent continuously. Subsequently, when the terminal A 1801 transmits a signal including the priority "1" in the TI section 1826 after the second data slot 1825, the terminal B 1802 receiving the terminal A 1801 receives the terminal A 1801. Knowing that the use of the data slot has ended, the packet may be transmitted using the data slot 1827.

Terminal C 1803 also uses data slot 021, where terminal C 1803 includes a priority of terminal C 1803 on TI interval 1822 after data slot 1821. When transmitting the terminal D, the terminal D 1804 may recognize that the use of the data slot of the terminal C 1803 is terminated and may transmit a packet by using the first data slot 1823. If the terminal D 1804 needs to use two data slots, the terminal D 1804 may configure data symbols continuously without the TI interval after the first data slot 1823 and use the data slot 1825.

At this time, the terminal E 1805 receives the signal including the priority of the terminal D 1804 in the TI period 1826 after the data slot 1825, but includes the priority of the terminal B 1802. Since the signal was not received, the terminal E 1805 cannot use the data slot until the data frame ends.

Referring to FIG. 20, data slots 2 and 3 of the y + N data frame 2001 are continuously used without a TI section. By allocating data slots in succession, a variable rate PA is possible. In a frame where a resource of a PA is reserved, a packet retransmission is required after a PA reservation data slot or an additional packet is generated, so that a need to continue using the data slot may be used. At this time, consecutive data slots must not collide with data slots reserved by another CA or PA. The data slot 2 2002 included in the data frame y + 3N is used as a CA data slot by a terminal using the data slot 1 as a PA reserved data slot. The resource reservation type of the ACK slot for this is also "01".

Referring to FIG. 21, a terminal requesting a CA (hereinafter referred to as a 'CA terminal') transmits a preamble 2101 of a data slot as a reservation type, and a receiving terminal transmits an ACK slot 2103 for the corresponding data slot 2102. ) Is broadcasted with an identifier corresponding to the CA. In an embodiment of the present invention, an identifier corresponding to CA among resource reservation types is "10".

After receiving the ACK signal in which the resource reservation type is set to the identifier corresponding to the CA, all the terminals recognize that the CA is reserved from the data slot reserved by the CA to the last data slot of the data frame. That is, referring to FIG. 21, since a CA is requested and accepted by a receiving terminal in data slot 2102 of data frame y + 2N, data slots 1 to 3 from data slot 1 of data frame y + 3N are accepted. Reserved to CA data slot (2104).

On the other hand, if the terminal requesting CA intends to use all data slots included in the data frame, the terminal notifies the other terminal of the reservation of all data slots through the TI section 2106 after the last data slot 2105 used as the CA. The receiving terminal broadcasts the resource reservation type of the ACK slot 2107 with an identifier corresponding to a CA extension. In an embodiment of the present invention, an identifier corresponding to CA extension among resource reservation types is "11". Referring to FIG. 21, since the CA extension is requested in the TI interval 2106 after the last data slot 2105 of the data frame y + 4N, the receiving terminal accepts through the last ACK slot 2107, and thus, y + 5N All data slots in the data frame have been allocated to the CA terminal. The CA terminal may transmit the preamble of the data slot 2108 of the y + 5N data frame as a reservation type and transmit a packet using the data slots 2109 from 0 to 3.

Thereafter, if the CA terminal does not transmit the general type preamble or transmits the packet in the data slot, the receiving terminal returns the resource reservation type of the ACK slot to "00" to broadcast. Referring to FIG. 21, since there are three data slots that were initially reserved for CA, even when the CA reservation is terminated, data slots 0 through 2 are allocated to CA terminals even if the CA reservation is terminated.

If a CA resource reservation conflicts with a PA resource reservation, the PA is subject to a higher priority than the CA. That is, the CA terminal may continuously use the remaining data slots except the data slot reserved for the PA.

Table 1 is a table showing the QoS support status of the distributed resource allocation method of the present invention.

class delay jitter data
rate applications resource
reservation priority
scheduling multiple
channel
access class1 medium low low (periodic, constant)
VoIP Periodic
Allocation (PA) No No class2 medium low variable (periodic, variable)
video streaming Periodic
Allocation (PA) No Yes class3 - - medium, high (non-periodic, bulk)
File transfer Continuous
Allocation (CA) No Yes class4 medium,
high - (non-periodic, delay bound)
chatting, gaming No High
scheduling
priority No class5 - - (backgroud)
SMS, MMS No No No

Referring to Table 1, services corresponding to class 1 and class 2 are sensitive to packet transmission delay, and packets are periodically generated. Therefore, a PA or variable PA resource allocation scheme is applied to satisfy the QoS for this.

On the other hand, since class 3 requires a high data transfer rate such as large file transfer, CA resource allocation scheme is applied. Although class 4 has a requirement for packet transmission delay, a packet may occur aperiodically or intermittently, so that a scheduling priority may be set high to provide a service.

At least some functions of the apparatus and method for transmitting / receiving a synchronization channel according to the embodiment of the present invention described above may be implemented in hardware or software coupled to the hardware. Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (19)

A method for transmitting data by a transmitting terminal included in a terminal-to-terminal direct communication network,
Determining a data frame to transmit the data, wherein the data frame includes a transmission request interval, a transmission response interval, and a data transmission interval;
Requesting a reception terminal to receive the data for reservation of the data transmission section in the transmission request section;
Receiving a response signal transmitted in the transmission response interval from the receiving terminal, and
Analyzing the response signal and transmitting the data through the data transmission interval
Including,
The transmission request interval and the transmission response interval, respectively, a scheduling code (SC) used to identify a link established between the transmitting terminal and the receiving terminal and to determine the scheduling priority and allocation type of the transmitting terminal. Comprising a data transmission method. In claim 1,
Before the determining step,
Sending a link establishment request message, and
Receiving a link establishment response message in response to the link establishment request message to obtain a link identifier
Data transmission method further comprising. In claim 1,
The determining step,
Determining the data frame according to an orthogonal frequency division multiplexing (OFDM) scheme
Including,
The data frame includes an ACK channel for transmitting and receiving an ACK signal for the data transmitted in the data transmission interval, and the data transmission interval includes a plurality of data slots. In claim 1,
The determining step,
Determining one data channel of a plurality of data channels included in the data frame according to an orthogonal frequency division multiple access (OFDMA) scheme
Including,
The data frame includes an ACK channel for transmitting and receiving an ACK signal for the data transmitted in the data transmission interval, and the data transmission interval includes a plurality of data slots. In claim 4,
Determining the data channel,
Calculating a scheduling priority (SP) of the transmitting terminal based on a function of an identifier of the transmitting terminal, a link identifier between direct communication terminals, a time identifier, a data QoS index, and a resource load index; and
Selecting a data channel including an SP of the transmitting terminal among the plurality of data channels
Data transmission method comprising a. In claim 5,
The requesting step,
Transmitting a resource request signal by using a radio resource corresponding to an SP of the transmitting terminal among radio resources included in the transmission request interval;
Data transmission method comprising a. In claim 6,
The transmitting step,
Analyzing the SP corresponding to at least one radio resource in which the response signal is received, determining a rank of the SP of the transmitting terminal; and
Transmitting the data using a first data slot corresponding to the determined rank among the plurality of data slots.
Data transmission method comprising a. In claim 7,
The transmitting step,
When the transmission of the data is finished, in the transmission indicator interval after the first data slot, broadcasting a transmission indicator signal by using a radio resource corresponding to the SP of the transmitting terminal
Data transmission method further comprising. In claim 8,
After the transmitting step,
Receiving the ACK signal in a first ACK slot corresponding to the first data slot among a plurality of ACK slots included in the ACK channel
Data transmission method further comprising. In claim 9,
The transmitting step,
Transmitting a reservation type preamble in the first data slot, and
Transmitting a periodic allocation (PA) request message requesting periodic reservation of the data slot in the first data slot
More,
Receiving the ACK signal,
Receiving a PA ACK signal indicated by an identifier corresponding to a PA in a resource reservation type in the first ACK slot
Including;
After receiving the PA ACK signal, using a first data slot included in a next data frame of the data frame as a PA reserved data slot
Data transmission method further comprising. In claim 9,
The transmitting step,
Transmitting a reservation type preamble in the first data slot, and
Transmitting a continuous allocation (CA) request message requesting continuous reservation of the data slot in the first data slot
More,
Receiving the ACK signal,
Receiving a CA ACK signal in which the resource reservation type is indicated by an identifier corresponding to a CA in the first ACK slot;
Including;
After receiving the CA ACK signal, using a first data slot to a last data slot included in a second data frame that is a next data frame of the data frame as a CA reserved data slot
Data transmission method further comprising. In claim 11,
After using the first data slot included in the next data frame of the data frame to the last data slot as a CA reserved data slot,
In case of continuously reserving all data slots included in the third data frame, which is the next data frame of the second data frame, after using the last data slot of the second data frame, the radio resource corresponding to the SP of the transmitting terminal is allocated. Broadcasting the transmission indicator signal by using
Data transmission method further comprising. A method for receiving data by a receiving terminal included in a terminal-to-terminal direct communication network,
Receiving a request signal for requesting a reservation of a data transmission section included in the data frame from a transmitting terminal transmitting the data in the transmission request section included in the data frame;
Broadcasting a response signal in a transmission response period included in the data frame;
Receiving a signal field of a plurality of data slots included in the data transmission interval, identifying a first data slot used by a transmitting terminal having a matching link identifier among the plurality of data slots, and
Receiving the data in the first data slot
Including,
The transmission request interval and the transmission response interval, respectively, a scheduling code (SC) used to identify a link established between the transmitting terminal and the receiving terminal and to determine the scheduling priority and allocation type of the transmitting terminal. Comprising a data reception method. A method for receiving data by a receiving terminal included in a terminal-to-terminal direct communication network,
Receiving a request signal for requesting a reservation of a data transmission section included in the data frame from at least one transmitting terminal in the transmission request section included in the data frame,
Determining a transmitting terminal to transmit a response signal among the at least one transmitting terminal by dividing the request signal through an allocation type (AT) region and a scheduling priority (SP) region in the transmission request interval; ,
Transmitting the response signal to the determined transmitting terminal in a transmission response period included in the data frame, and
Receiving the data transmitted by the determined transmission terminal in the data transmission interval
Data receiving method comprising a. The method of claim 14,
The determining step,
Determining a priority of the at least one transmitting terminal based on the signal received in the AT area; and
Determining a transmitting terminal having the highest priority among the at least one transmitting terminal as a transmitting terminal to which a response signal is to be transmitted;
Data receiving method comprising a. The method of claim 15,
Transmitting the response signal,
Transmitting the response signal to the determined transmitting terminal by using the radio resource used in the determined transmitting terminal.
Data receiving method comprising a. The method of claim 14,
The determining step,
Determining the priority of the at least one transmitting terminal based on the signal received in the SP region when there is no signal received in the AT region, and
Determining a transmitting terminal having the highest priority among the at least one transmitting terminal as a transmitting terminal to which a response signal is to be transmitted;
Data receiving method comprising a. The method of claim 17,
Transmitting the response signal,
Transmitting the response signal to a terminal transmitting a signal in the SP region by using a radio resource used in the SP region.
Data receiving method comprising a. The method of claim 14,
After receiving the data,
Transmitting an ACK signal for the received data by using a radio resource included in a transmission response interval included in a next data frame of the data frame
The data receiving method further comprises.

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