CN103078726B - The method and apparatus of relay transmission - Google Patents

Abstract

The embodiment of the present invention discloses a method and equipment for relay transmission. The method includes: selecting a subframe in a time division duplex TDD relay frame as a relay link subframe, and selecting a subframe in a TDD relay frame Subframes used as relay link subframes include: selecting a downlink subframe in a TDD relay frame as a downlink relay link subframe, and/or selecting a downlink subframe in a TDD relay frame as an uplink relay link subframe frame, and/or select an uplink subframe in a TDD relay frame as an uplink relay link subframe; perform relay transmission according to the relay link subframe. In the embodiment of the present invention, when performing data transmission, subframes that can be used for relay link transmission are selected, and when using the relay link for data transmission, the inherent constraints of the TDD frame structure in the prior art are complied with, and the use of The system of TDD relay frames performs coverage extension, so that the throughput is enhanced.

Description

Method and device for relay transmission

technical field

The present invention relates to the technical field of communication, in particular to a method and equipment for relay transmission.

Background technique

With the development of wireless communication technology, there is a higher demand for communication speed and communication quality. Wired transmission meets the demand for communication speed and communication quality to a certain extent, but wired transmission requires operators to lay optical cables or rent wired resources. , which imposes constraints on the use of wired transmission. This problem is effectively solved by using Relay (relay) as the wireless backhaul transmission. The Relay technology can expand the coverage of the cell, improve the capacity of the cell, and equalize the throughput of the cell. The introduction of Relay will bring changes to the frame structure of the original system.

In the prior art, a Relay frame structure using TDD (TimeDivisionDuplex, Time Division Duplex) is shown in Figure 1, eNB (enhancedNodeB, base station) and RN (RelayNode/Relay, relay station) and RN and UE (UserEquipment, user equipment ) to communicate from subframe1 (subframe 1) to subframe4. subframe1 is used for the DL (Downlink, downlink) relay link of eNB->Relay, subframe2 is used for the DL access link of Relay->UE, and Subframe3 is used for the UL (Uplink, uplink) relay link of Relay->eNB Road, Subframe4 is used for the UL access link of UE->Relay.

In the course of realizing the present invention, the inventor finds that there are at least the following problems in the prior art:

In the existing relay system, when data transmission is performed according to the TDD frame structure in the prior art, the relay transmission cannot be realized.

Contents of the invention

Embodiments of the present invention provide a method and device for relay transmission, so that relay stations in a TDD system can implement relay transmission.

In order to achieve the above purpose, an embodiment of the present invention proposes a relay transmission method, including:

Selecting the subframe in the time division duplex TDD relay frame as the relay link subframe, said selecting the subframe in the TDD relay frame as the relay link subframe includes: selecting the downlink subframe in the TDD relay frame as the relay link subframe The downlink relay link subframe, and/or select the downlink subframe in the TDD relay frame as the uplink relay link subframe, and/or select the uplink subframe in the TDD relay frame as the uplink relay link subframe frame;

Perform relay transmission according to the relay link subframe.

The embodiment of the present invention also proposes a communication device, including:

A selecting module, configured to select a subframe in a time division duplex relay frame as a relay link subframe, said selecting a subframe in a TDD relay frame as a relay link subframe includes: selecting a subframe in a TDD relay frame The downlink subframe in the TDD relay frame is used as the downlink relay link subframe, and/or the downlink subframe in the TDD relay frame is selected as the uplink relay link subframe, and/or the uplink subframe in the TDD relay frame is selected Used as an uplink relay link subframe;

A transmission module, configured to perform relay transmission according to the relay link subframe selected by the selecting module.

According to the technical solution provided by the embodiment of the present invention, the communication device selects a subframe that can be used for relay link transmission when performing data transmission, and conforms to the TDD frame structure in the prior art when using the relay link for data transmission Inherent constraints, and coverage extension for systems using TDD relay frames, resulting in enhanced throughput.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 is a schematic diagram of a relay frame structure in the prior art;

FIG. 2 is a flowchart of a relay transmission method proposed in Embodiment 1 of the present invention;

FIG. 3 is a schematic diagram of a frame structure in which relay transmission is not introduced into TDD in Embodiment 1 of the present invention;

FIG. 4 is a schematic diagram of a frame structure using a complete subframe as a relay link in Embodiment 1 of the present invention;

FIG. 5 is a schematic diagram of a frame structure using DL subframes as DL relay links and UL subframes as UL relay links in Embodiment 1 of the present invention;

FIG. 6 is a schematic diagram of a frame structure of a system including eNB, RN, and UE in Embodiment 1 of the present invention;

FIG. 7 is a schematic diagram of a frame structure proposed by Embodiment 2 of the present invention;

FIG. 8 is a schematic diagram of another frame structure proposed by Embodiment 2 of the present invention;

FIG. 9 is a schematic diagram of another frame structure proposed by Embodiment 2 of the present invention;

FIG. 10 is a schematic diagram of a frame structure proposed in Embodiment 3 of the present invention;

FIG. 11 is a schematic diagram of a frame structure proposed in Embodiment 4 of the present invention;

FIG. 12 is a schematic diagram of a frame structure proposed in Embodiment 5 of the present invention;

FIG. 13 is a schematic diagram of another frame structure proposed by Embodiment 5 of the present invention;

FIG. 14 is a schematic diagram of a frame structure proposed in Embodiment 6 of the present invention;

FIG. 15 is a schematic diagram of a frame structure proposed by Embodiment 7 of the present invention;

FIG. 16 is a schematic structural diagram of a communication device proposed in Embodiment 8 of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

A relay transmission method proposed in Embodiment 1 of the present invention, as shown in FIG. 2 , includes:

Step S201, selecting a subframe in the time division duplex TDD relay frame as a relay link subframe;

Selecting a subframe in a TDD relay frame as a relay link subframe includes: selecting a downlink subframe in a TDD relay frame as a downlink relay link subframe, and/or selecting a downlink subframe in a TDD relay frame The frame is used as an uplink relay link subframe, and/or an uplink subframe in a TDD relay frame is selected as an uplink relay link subframe.

Step S202, performing relay transmission according to the relay link subframe.

When performing relay transmission according to the selected relay link subframe, if the downlink subframe in the relay frame is used as an uplink relay link subframe or a downlink relay link subframe, select the previous subframe in the downlink subframe N OFDM symbols are transmitted as the relay and the UE under the relay, or as the access link between the base station and the UE under the base station, and are used to send downlink pilots, or downlink pilots and control signaling, the The remaining OFDM symbols in the downlink subframe are used as relay link transmission and/or guard time, that is, the time except the first N OFDM symbols in the downlink subframe is used as relay link transmission and/or guard time .

There are M OFDM symbols in the downlink subframe, the M and N are natural numbers, and N is smaller than M.

The solutions provided by the embodiments of the present invention can be applied to LTE, LTEAdvanced, various versions of LTE (Rel-8, Rel-9, Rel-10, etc.), World Interoperability for Microwave Access (WiMax), ultra-wideband wireless communication ( Ultra-Wideband, UMB) and other systems.

For example, in the LTE/LTE-A system, the communication device transmits data according to the TDD relay frame. One frame of the TDD relay frame contains 10 subframes, and the length of one frame is 10ms, and the length of each subframe is 1ms. . The LTE/LTE-ATDD relay frame includes a relay link subframe, an access link subframe and a guard time, the relay link subframe occupies one or more subframes, and the access link subframe Occupying one or more subframes, the guard time occupies a part of the special subframe of LTE/LTE-ATDD; or the guard time occupies a part of the relay link subframe. The communication between the base station and the user equipment served by the base station may be performed according to the relay link subframe; and/or the communication between the base station and the relay station may be performed according to the relay link subframe; and/or according to the The relay link subframe performs communication between the relay station and the user equipment served by the relay station. When the base station or the relay station performs relay transmission, the TDD frame with the same ratio of the downlink subframe to the uplink subframe can be applied, and the frame with the same configuration can also be applied. The protection time specifically includes: time for transmitting and receiving state transition and idle time, the time for the transition of the transmitting and receiving state is the time for the transition of the transmitting and receiving state of the base station and/or the time for the transition of the transmitting and receiving state of the relay station; the protection time is an integer multiple of the sampling time, or the protection time Is that the number of sampling points is a divisor of the number of Fourier transform points, the number of sampling points is the number of Fourier transform points/2^n, and the n is a natural number; or, the guard time can also be obtained from the cyclic prefix of the OFDM symbol, the OFDM symbol and the subframe At least one kind of acquisition; or the guard time is adjusted by both sending parties in signaling.

In all embodiments of the present invention, D in the drawings represents subframes for downlink, U in the drawings represents subframes for uplink, and S in the drawings represents the subframes in the LTE/LTE-ATDD system Special subframe, in this special subframe, includes DwPTS (DownlinkPilotTimeslot, downlink pilot time slot), UpPTS (UplinkPilotTimeslot, uplink pilot time slot) and guard time (GP), similarly, D in the table also represents For downlink subframes, U in the table represents uplink subframes, and S in the table represents special subframes for DwPTS, UpPTS and guard time.

In the TDD relay frame structure, if UE sends PUSCH (PhysicalUplinkSharedChannel, Physical Uplink Shared Channel) in subframe (subframe) n, UE will receive PHICH (PhysicalHARQIndicationChannel, PhysicalHARQIndicationChannel, Physical Hybrid Automatic Repeat Indication Channel), where the values of n and k (where k is 0-6 are the values in the configuration line) are shown in Table 1.

Table 1

For example, in Table 1, for the 3rd (n=3) subframe in this frame, in the 0th configuration row, the corresponding k value is 7, then the UE sends PUSCH in the 3rd subframe, and will send PUSCH in the next frame The PHICH is received in the 0th subframe (3+7). For the next configuration, for example, in the first configuration row, the corresponding k value is 6, then the UE sends PUSCH in the third subframe, and receives PHICH in the ninth subframe (3+6).

In the TDD Relay frame structure, if UE receives PDSCH (PhysicalDownlinkSharedChannel, Physical Downlink Shared Channel) in subframe, it will send ACK/NACK (timing index) in subframe+k, where n, k (k value is 0~6 configuration The values in the row) are shown in Table 2.

Table 2

For example, in Table 2, for the third subframe in this frame, in the second matching row, the corresponding k value is 4, then the UE receives the PDSCH in the third subframe, and will +4) Send ACK/NACK. For the next configuration, for example, in the 5th configuration row, the corresponding k value is 9, then the PDSCH received by the UE in the 3rd subframe of the UL will be in the 2nd subframe (3+9) of the next frame Send ACK/NACK.

In the TDD Relay frame structure, if UE receives ULgrant/PHICH in subframe (mobilizes uplink data/or ANK/NACK of ULPUSCH), then sends PUSCH in subframe+k, and the corresponding relationship between ULgrant/PHICH and PUSCH is shown in Table 3 (ULgrant in the table below can be replaced by PHICH, which will not be marked below).

table 3

Wherein, G in Table 3 means grant (scheduling UL data signaling), and Gn-k means that UE receives UL grant in subframe and sends PUSCH in UL subframe n+k. For example, in the first subframe, when the ratio of DL (downlink subframe) to UL (uplink subframe) is 2:2, the correspondence between ULgrant and PUSCH is G1-6, that is, the UE receives UL grant, PUSCH will be sent in the seventh subframe (1+6).

As shown in FIG. 3 , it is a schematic diagram of a frame structure in which relay transmission is not introduced into TDD in Embodiment 1 of the present invention. Pattern A represents the time unit of DL and UL communication between eNB and UE_eNB (UE served by eNB), and the time unit in the figure is subframe (one subframe is 1 ms). Each DL subframe performs eNB->UE_eNB DL communication, and each UL subframe performs UE_eNB->eNB UL communication. When the frame structure of relay transmission is introduced in TDD, as shown in FIG. 4, it is a schematic diagram of a frame structure using a complete subframe as a relay link in Embodiment 1 of the present invention. In FIG. 4, DL may have One or more subframes are used as a relay link between eNB and RN, and correspondingly, one or more subframes are used as a relay link between RN and eNB in UL. When the relay link is used exclusively for UL and DL communication between eNB and RN, the relay link is called a dedicated relay link. When the relay link is used as both eNB and RN and eNB and UE_eNB When communicating, this relay link is called a non-dedicated relay link. The number of subframes used for the relay link in UL and DL may be different or the same. The DL and UL relay links of the RN shown in FIG. 4 may occupy a complete relay link subframe, or a part of the relay link subframe except the guard time. When the frame structure of relay transmission is introduced in TDD, as shown in FIG. 5 , the original DL subframe is used as the DL relay link and the original UL subframe is used as the UL relay link in Embodiment 1 of the present invention. In Figure 5, pattern A represents the communication link between eNB and UE_eNB and the communication link between RN and UE_RN, which can be used to transmit control channels, data channels, pilots, synchronization channels, broadcast channels, etc. used by LTE Channel. In order to avoid channel interpolation between DL subframes in the time domain, the first few (1 or 2 or 3 or 4) symbols (sampling time) of the subframe where the DL relay link is located, as shown in Figure 5 B, as the access link between eNB and UE_eNB and between RN and UE_RN, the access link (pattern B) is used to send DL pilot, control channel, PHICH, PCFICH, if only Send DL pilot, or send DL pilot and physical downlink control channel (PhysicalDownlinkControlChannel, PDCCH), physical hybrid automatic retransmission request indicator channel (PhysicalHybridARQIndicatorChannel, PHICH), physical control format indicator channel (PhysicalControlFormatIndicatorChannel, PCFICH) and other control signaling. In the LTE/LTE-ATDD system, the DL subframe where the pattern B is located may be a Multi-media Broadcast over a Single Frequency Network (MBSFN) subframe, and the pattern B is equivalent to the unicast part of the MBSFN subframe, which is used in the eNB DL pilots, or DL pilots and control channels, PHICH, PCFICH and other control signaling are sent on the access link with UE_eNB and the access link between RN and UE_RN, and the rest of the MBSFN subframe is used It is used as DL communication and guard time between eNB and RN. Channel estimation performance is further improved by sending the pilot to interpolate channel estimation with the pilot of the previous subframe. When the frame structure of relay transmission is introduced into the Relay frame structure of TDD, as shown in FIG. 6 , it is a schematic diagram of a frame structure of a system including eNB, RN, and UE in Embodiment 1 of the present invention. Pattern A represents the link between eNB and UE_eNB for DL and UL communication, and also represents the link between RN and UE_RN for DL and UL communication; pattern B represents the downlink relay link from eNB to RN, which can be used to send control channels, data Channels, pilots, etc.; pattern C represents the downlink access link, which is used for eNB to UE_eNB and RN to UE_RN respectively, and can transmit PHICH, ULgrant, PCFICH, DL pilot and other channels. Occupy the first few (1 or 2 or 3 or 4) OFDMsymbols of the subframe where the pattern C is located, for the downlink access link eNB to UE_eNB and the downlink access link RN to UE_RN, which can transmit PHICH, UL grant, PCFICH and other control signaling and/or DL pilot and other information. Pattern E is to convert the corresponding part of the original DL subframe from eNB to UE_eNB into the uplink from RN to eNB, that is, the subframe where pattern E is located, and use the original DL subframe as the uplink relay link subframe. In the LTE/LTE-ATDD system, the DL subframe where pattern E is located can be an MBSFN subframe, and pattern C is equivalent to the unicast part in the MBSFN subframe, which is used for the access link between eNB and UE_eNB and between RN and UE_RN DL pilots, and/or control signaling such as PDCCH, PHICH, PCFICH, etc. are sent on the access link between the MBSFN subframes, and the rest of the MBSFN subframe is used for UL communication and guard time between eNB and RN. Pattern D represents guard time, and this guard time comprises transceiving state transition time and idle time, and this transceiving state transition time is the transceiving state transition time of base station and/or the transceiving state transition time of relay station; The length of this guard time can be sampling time Integer multiple or equal to [N/(2^n)×sampling time], where N is the number of Fourier transform points used in the LTE or LTE-A system, n is a natural number 1, 2, 3..., 2^n<= N. Pattern E is an uplink relay link from RN to eNB.

In Figure 6, the pattern A of the UL part can be used as the UL access link for transmitting UE_eNB to eNB, and can also be used as the UL access link for transmitting UE_RN to RN; the pattern A of the DL part can be used as the UL access link for transmitting eNB to UE_eNB The DL access link can also be used as a DL access link from the transmission RN to UE_RN, the pattern B of the DL part can be used as the DL relay link from the eNB to the RN, and the pattern B of the DL part can also be used as the transmission eNB A hybrid link of the DL relay link to RN and the DL access link from eNB to UE_eNB; pattern B is used as the relay link from eNB to RN, if the throughput required by the relay link does not need to use all pattern B resources, pattern B can also transmit one or all of the data channel, control channel, and pilot channel from eNB to UE_eNB at the same time. Pattern D is the time when the eNB and or RN do not transmit data, which can be used as the transition time of the eNB's transceiver state and/or the transition time of the RN's transceiver or transmit-receive transition, and can also be used as the idle (idle) time. As shown in Figure 6, the RN's There may also be a pattern D between the pattern C and the pattern E. The pattern D depends on whether the time passing the distance between the eNB and the RN satisfies the sending and receiving conversion time of the eNB. When passing the distance between the eNB and the RN When the time of is greater than the transceiving transition time, the first pattern D of the subframe where the eNB is located in the UL needs to be greater than the transceiving transition time. When the time for passing the distance is less than the transceiving transition time, pattern D needs to be added between pattern C and pattern E of the RN, and the length of time (pattern D) is the sum of the transceiving transition time of eNB and the transmission time from RN to eNB. That is, the time length of the pattern D may be different at different positions, but they all need to be located in the subframe where the relay link is located. The above-mentioned conversion time or transmission time (for example, pattern D in FIG. 6 ) can also be adjusted by both sending parties in signaling such as timing adjustment, instead of being expressed in the frame structure.

It can be seen that in this embodiment, the communication device selects subframes that can be used for relay link transmission when performing data transmission, and when using the relay link for data transmission, it conforms to the inherent constraints of Rel-8 of the LTE system , and by using the LTE/LTE-ATDD relay frame to extend the coverage of the LTE system, the throughput is enhanced.

In all embodiments of the present invention, the ratio of the downlink subframe to the uplink subframe is the ratio of the downlink subframe to the uplink subframe when the relay is not introduced. After the relay is introduced, the downlink subframe The matching ratio with the uplink subframe may change, depending on the actual situation.

The ratio of a LTE/LTE-ATDD relay frame proposed in Embodiment 2 of the present invention is a frame structure when the ratio of downlink subframes to uplink subframes is 6:3. In this embodiment, the positions of ULgrant and PUSCH The corresponding relationship is shown in Table 4. For example, if the UE receives the UL grant of the UE in subframe 0, the UE should send the PUSCH in the corresponding subframe 4. If the UE receives the UL grant for the UE in subframe 8/9, the UE should send PUSCH in subframe 2/3 corresponding to the next frame.

Table 4

Table 5 shows the corresponding relationship between PHICH and ULACK/NACK positions. Those with the same pattern in Table 5 have a corresponding positional relationship. For example, when UE sends PUSCH in subframe 4, correspondingly sends PHICH at subframe 0 of the next frame, sends PDSCH at subframe 0, and correspondingly sends ULACK/NACK at subframe 4 of this frame.

table 5

In the frame structure of LTETDD, subframes 0, 1, 5, and 6 are used to send P-BCH (PrimaryBroadcastChannel, main state broadcast channel), D-BCH (DynamicBroadcastChannel, dynamic broadcast channel) P/S-SCH (Primary/SecondarySynchronizationChannel , primary/secondary synchronization channel), in this frame structure, subframes 0, 1, 5, and 6 cannot be selected as the downlink relay link. It can be seen from Table 5 that the available DL relay subframes can only be subframes Frames 7, 8, 9. It can also be seen from Table 5 that subframes 0, 1, 5, and 6 respectively correspond to subframes 2 and 4 in ULACK/NACK, so subframes 2 and 4 cannot be used as UL relay links. It can be seen from Table 5 that only subframe 3 can be selected as the UL relay link. UE receives PDSCH in subframe 7 and subframe 8, correspondingly needs to send ULACK/NACK in subframe 3 (7+6 or 8+5) of the next frame, and can choose to use subframe 7 and subframe 8 as DL relay link at the same time . It can be seen from Table 4 that subframe 8 also needs to send the PUSCH of subframe 2 in the next frame. When subframe 8 does not send UL grant, it will cause subframe 2 to fail to send PUSCH, resulting in waste of resources. Therefore, it can be selected The first few (1 or 2 or 3 or 4) OFDM symbols in subframe 8 are used for the transmission of the access link, through the first few symbols of subframe 8, downlink control channels, PCFICH, PHICH, etc. can be sent between eNB and UE_eNB Control signaling and/or pilots, downlink control channels, PCFICH, PHICH and other control signaling and/or pilots can be sent between RN and UE_RN. It can be seen from Table 4 that when the UL grant is sent in subframe 9 of the previous frame, PUSCH needs to be sent in subframe 3 of this frame, and subframe 3 is used as the relay link between RN and eNB. 3 When sending PUSCH, RN cannot receive the data sent by UE_RN. Therefore, under the above combination, subframe 9 of the previous frame cannot send the UL grant control channel in PDCCH to schedule UL data. Therefore, one or more of the subframes [3, 7, 8, 9] can be selected as downlink relay link subframes, and the remaining subframes can be used as uplink relay link subframes for uplink relay The number of link subframes is greater than or equal to 1, and subframe 3 can only be used as an uplink relay link subframe.

As shown in FIG. 7 , it is a schematic diagram of a frame structure including a relay link and an access link proposed in Embodiment 2 of the present invention. The ratio of downlink subframes to uplink subframes in the original LTE system is 6:3. In this frame structure, the combination of subframes selected as the relay link is [3, 7, 8], and the D-Psubframe and U-Psubframe in Figure 7 are the relay time for the communication between the RN and the eNB, respectively Indicates the DL and UL relay time of RN and eNB communication, and the UL communication part between RN and eNB can also be used to transmit UL control channel, data channel, pilot, etc. between UE and eNB. The AB pattern in Figure 7 represents the access link for eNB and UE_eNB and the access link for RN and UE_RN, which can be used to send pilot, DL control channel, PCFICH, PHICH, for example, only send pilot, or Send pilot and DL control channel, PCFICH, PHICH and other control signaling. The AC pattern in the subframe where the Psubframe is located can be used for the time of sending and receiving or switching between sending and receiving of the RN and the propagation time delay between the eNB and the RN. In all the drawings of this embodiment of the present invention, the same AB patterns as in FIG. 7 represent the access link between eNB and UE_eNB and the access link between RN and UE_RN, and the same AC patterns as in FIG. The transmission and reception or switching time between transmission and reception of the RN and the propagation time delay between the eNB and the RN will not be repeated in the following description.

As shown in FIG. 8 , it is a schematic diagram of a frame structure including a relay link and an access link proposed in Embodiment 2 of the present invention. The ratio of downlink subframes to uplink subframes in the original LTE system is 6:3. In this frame structure, the combination of subframes selected as the relay link is [3, 7, 8, 9], that is, subframe 3 is used as RN->eNB, and subframes 7, 8, and 9 are used as eNB-> RN. That is, subframe 3 is selected as the uplink relay link subframe, and subframe 7, subframe 8, and subframe 9 are selected as the downlink relay link subframe. When the UL subframe is used as the DL of the relay link, since the communication from the RN to the eNB will cause large UL interference to the communication between the UE_eNB and the eNB in the neighboring cell, the feasibility is very low, and the DL subframe is used as the RN to communicate with the eNB In the case of UL, the interference from eNBs of adjacent cells in the UL direction is smaller than the interference when the UL subframe is used as the DL relay link, and the DL subframe can be selected as the UL relay link. It can be seen from Table 4 that the UL grant sent in subframe 9 of the previous frame corresponds to the PUSCH sent in subframe 3. If subframe 9 is changed to UL, there will be no UL grant in subframe 3, and there will be no UL grant in subframe 9. To send PHICH, subframe 7 can be selected as the DL of the eNB->RN, that is, the relay link, and subframe 9 can be selected as the UL of the RN->eNB, that is, the relay link. In order not to waste subframe 3 resources, several OFDMsymbols in front of subframe 9 can be used to send control channels, such as ULgrant, PHICH, PCFICH, etc. control signaling and/or pilots for subframe 3 of the next frame. Transmission of pilots also facilitates channel estimation interpolation between access link subframes.

As shown in FIG. 9 , it is a schematic diagram of a frame structure in which the ratio of downlink subframes to uplink subframes of an original LTE system including relay links and access links proposed in Embodiment 2 of the present invention is 6:3. In this frame structure, the combination of subframes selected as the relay link is [7, 9]. Subframe 7 can be selected as the subframe of the downlink relay link, and subframe 9 can be selected as the subframe of the uplink relay link. frame; or conversely, select subframe 7 as an uplink relay link subframe, and select subframe 9 as a downlink relay link subframe. Specifically, when subframes 0, 1, 2, 3, 4, 5, 6, and 8 are respectively used as the uplink and downlink access links from eNB to UE_eNB, and the uplink and downlink access links from RN to UE_RN, eNB and UE_eNB On the access link, control channels, data channels, and pilot channels are sent to each other. On the DL access link, eNB also sends broadcast channels and synchronization channels. RN and UE_RN send control channels, data channels, and so on to each other on the access link. The pilot channel, on the DL access link, the RN will also send the broadcast channel and the synchronization channel; in the subframe where the relay link is located, subframe 9 in the frame structure shown in Figure 9, the subframe of the subframe of the eNB The first 1 to 4 OFDMsymbs are used for the eNB to send pilots and/or control channels to the UE under it, and the next part is the eNB’s sending and receiving conversion time, followed by the relay link Psubframe time, and then the eNB’s sending and receiving conversion time. For the RN, the first 1 or 2 or 3 or 4 OFDMsymbols of the subframe are used for the eNB and the RN to send the control channel, PHICH, PCFICH and other control signaling and/or pilot to the UE under it respectively. Transmission of pilots also facilitates channel estimation interpolation between access link subframes. The next part is the relay link Psubframe time of the RN, followed by the sending and receiving conversion time of the RN, which takes into account the time when the eNB can effectively receive the relay area Psubframe. According to business and system capacity requirements, a Psubframe can be located in multiple subframes and is a part of a subframe. In addition, in the original LTE system including the relay link and the access link, the ratio of the downlink subframe to the uplink subframe is a 6:3 frame structure. In this frame structure, the subframe selected as the relay link The combination is [7, 8], subframe 7 can be selected as the subframe of the downlink relay link, and subframe 8 can be selected as the subframe of the uplink relay link; or vice versa, subframe 7 can be selected as the subframe of the uplink relay link For the link subframe, select subframe 8 as the subframe for the downlink relay link; or select one or more of the subframes [3, 7, 8, 9] as the subframe for the downlink relay link, and the remaining The subframes of are used as uplink relay link subframes, the number of uplink relay link subframes is greater than or equal to 1, and subframe 3 can only be used as uplink relay link subframes.

It can be seen that in this embodiment, by selecting subframes for relay link transmission in the frame structure in which the ratio of downlink subframes to uplink subframes is 6:3, when using the relay link for data transmission, it conforms to And the inherent constraints of the Rel-8 of the LTE system when the ratio is 6:3, and by using the LTE/LTE-ATDD relay frame to extend the coverage of the LTE/LTE-A system, the throughput is enhanced.

Embodiment 3 of the present invention proposes an LTE/LTE-ATDD frame structure in which the ratio of downlink subframes to uplink subframes is 3:1. In this embodiment, the corresponding relationship between ULgrant and PUSCH is shown in Table 6. For example, if the UE receives the UL grant of the PDCCH in subframe 3, it will send the PUSCH channel in subframe7 of this frame, and the UE receives the UL grant in subframe 8, and will send the PUSCH channel in subframe2 of the next frame.

Table 6

Table 7 shows the corresponding relationship between PHICH and ULACK/NACK positions. Those with the same pattern in Table 7 have a corresponding positional relationship.

Table 7

In Table 7, subframes 0, 1, 5, and 6 are used to send broadcast channels and synchronization channels, and are not selected as relay links. Subframes 2 and 7 will receive UL ACK/NACK from the above subframe (the previous frame or this frame). When data is sent in subframe 2 and subframe 7 of this frame, PHICH will be sent in subframe 8, and when data is sent in subframe 7 of the previous frame, PHICH will be sent in subframe 3 of this frame. It is necessary to use subframe 4 and subframe 9 as the downlink and uplink of the relay link, that is, one or more of the subframes [3, 4, 8, 9] can be selected as the subframe of the downlink relay link, and the remaining are used as uplink relay link subframes, and the number of uplink relay link subframes is greater than or equal to one. Specifically, subframe 4 can be used as the DL of the relay link, that is, from eNB to RN, and subframe 9 can be used as the uplink of the relay link, that is, from RN to eNB, or vice versa, subframe 4 can be selected as the uplink relay As a link subframe, subframe 9 is selected as a downlink relay link subframe.

As shown in Figure 10, it is a schematic diagram of a frame structure proposed by Embodiment 3 of the present invention. Subframe 4 can be used as the DL of the relay link, that is, eNB->RN, and subframe 9 can be used as the relay link The UL of RN->eNB. Pattern AC in subframe 4 and subframe 9 represents the transition time for RN transmit-to-receive and receive-transmit. The length can be adjusted according to the distance from the eNB to the RN and the actual transition time of the receiving and receiving states. Optionally, when the original DL subframe is used as a relay subframe, the first few OFDMsymbols of the subframe can be used for access link eNB->UE and RN->UE, DL control channel, PCIFICH, PHICH, etc. Signaling and/or pilot, the insertion of the pilot helps to perform channel estimation interpolation between the pilot of the previous access link subframe and the pilot, and helps to improve the performance of channel estimation.

It can be seen that in this embodiment, by selecting subframes for relay link transmission in the frame structure in which the ratio of downlink subframes to uplink subframes is 3:1, when using the relay link for data transmission, it conforms to The inherent constraints of the Rel-8 of the LTE system when the ratio is 3:1, and the coverage of the LTE/LTE-A system is extended by using the LTE/LTE-ATDD relay frame, so that the throughput is enhanced.

Embodiment 4 of the present invention proposes an LTE/LTE-ATDD frame structure in which the ratio of downlink subframes to uplink subframes is 7:2. In this embodiment, the corresponding relationship between the positions of PHICH and ULACK/NACK is as follows As shown in Table 8, the corresponding relationship between the ULgrant and the PUSCH is shown in Table 9.

Table 8

Table 9

It can be seen from Table 8 and Table 9 that subframes 0, 1, 5, and 6 cannot be used as relay links, and the corresponding ULACK/NACK is sent in both UL subframes, so the DL subframes are selected to be As the DL and UL of the relay link, one or more of the subframes [4, 7, 8, 9] can be selected as the subframe of the downlink relay link, and the rest are used as the uplink of the relay link The number of subframes used as uplink relay link subframes is greater than or equal to one. As shown in Figure 11, it is a complete frame structure diagram including the relay link and the access link proposed by Embodiment 4 of the present invention. DL subframe 4 can be selected as eNB->RN, and DL subframe 7 as eNB->RN. RN->eNB, alternatively, subframe 4 is used as an uplink relay link subframe, and subframe 7 is selected as a downlink relay link subframe.

It can be seen that in this embodiment, by selecting subframes for relay link transmission in the frame structure in which the ratio of downlink subframes to uplink subframes is 7:2, when using the relay link for data transmission, it conforms to And the inherent constraints of the Rel-8 of the LTE system when the ratio is 7:2, and by using the LTE/LTE-ATDD relay frame to extend the coverage of the LTE/LTE-A system, the throughput is enhanced.

Embodiment 5 of the present invention proposes a frame structure in which the ratio of a downlink subframe to an uplink subframe is 2:2 in an LTE/LTE-ATDD frame. Similarly, according to the inherent constraints of LTETER-8 under this configuration, DL subframes [0, 1, 5, 6] and UL subframes [2, 7] are not suitable for relay links, so the subframes can be selected One or more of frames [3, 4, 8, 9] are used as downlink relay link subframes, and the remaining subframes are used as uplink relay link subframes, which are used as uplink relay link subframes The number of is greater than or equal to 1, and subframe 3 and subframe 8 can only be used as uplink relay link subframes.

As shown in Figure 12, it is a frame structure diagram proposed by Embodiment 5 of the present invention. In this embodiment, when there are 2 pairs of relay links in 10 ms, the relay sending and receiving conversion time is placed in the sub-link where the relay link is located. in frame. Since the value can be adjusted according to actual needs, such as the distance between the RN and the eNB and the time for sending/receiving conversion, they can also be placed adjacent to the UL and DL relay subframes. The subframe of the relay link Psubframe is [3, 4, 8, 9].

The above is 2 pairs of relay links in the 10ms frame structure, or there may be only 1 pair of relay links, as shown in Figure 13, which is another frame structure diagram proposed in Embodiment 5 of the present invention, in which the relay link is Transmitting and receiving transition time can be expressed implicitly in the frame structure, that is, by notifying the RN of the sending time or the cut-off time of receiving the eNB, or it can be explicitly marked by the AC area in the figure. The combination in the figure is [3, 9], that is, subframe 9 is used as eNB->RN, and subframe 3 is used as RN->eNB. In addition, when the combination is [4, 8], select subframe 4 as the subframe for the downlink relay link, and select subframe 8 as the subframe for the uplink relay link; when the combination is [3, 4, 8, 9], select subframes 4 and 9 as subframes for the downlink relay link, and select subframes 3 and 8 as subframes for the uplink relay link.

It can be seen that in this embodiment, by selecting subframes for relay link transmission in the frame structure in which the ratio of downlink subframes to uplink subframes is 2:2, when using the relay link for data transmission, it conforms to The inherent constraints of the Rel-8 of the LTE system when the ratio is 2:2, and the coverage of the LTE/LTE-A system is extended by using the LTE/LTE-ATDD relay frame, so that the throughput is enhanced.

Embodiment 6 of the present invention proposes a frame structure in which the ratio of the LTE/LTE-ATDD frame is 3:5 for the ratio of the downlink subframe to the uplink subframe, as shown in FIG. 14 , for the combination [4, 9] It is used as the subframe where the relay link Psubframe is located. Subframe 4 is uplink, used for RN->eNB, subframe 9 is downlink, used for eNB->RN, and there is a control channel similar to the above in subframe 9. Since the subframe of the relay link is close to the uplink and downlink conversion position of the original system, the original system has a guard time, so the guard time may not be drawn in the figure. The patterns AB in front of the 9th subframe respectively represent the access links of eNB->UE_eNB and RN->UE_RN, the length of which can be one of 1, 2, 3, and 4 symbols, and can send pilots, or Pilot and DCCH, PHICH, PCFICH and other control signaling.

It can be seen that in this embodiment, by selecting subframes for relay link transmission in the frame structure in which the ratio of downlink subframes to uplink subframes is 3:5, when using the relay link for data transmission, it conforms to The inherent constraints of the Rel-8 of the LTE/LTE-A system when the ratio is 3:5, and by using the LTE/LTE-ATDD relay frame to extend the coverage of the LTE/LTE-A system, the throughput is enhanced.

Embodiment 7 of the present invention proposes an LTE/LTE-ATDD frame structure in which the ratio of downlink subframes to uplink subframes is 8:1. Similarly, according to the inherent constraints of LTETER-8 under this configuration, DL subframes [0, 1, 5, 6] and UL subframes [2] are not suitable for relay links, so subframes [ 3, 4, 7, 8, 9] are used as downlink relay link subframes, and the remaining subframes are used as uplink relay link subframes, which are used as uplink relay link subframes The number of is greater than or equal to 1.

As shown in FIG. 15 , the ratio of the LTE/LTE-ATDD frame proposed in Embodiment 7 of the present invention is a frame structure diagram in which the ratio of the downlink subframe to the uplink subframe is 8:1, and the DL subframe 3 is selected. For uplink relay link RN to eNB, DL subframes [7, 8, 9] are used for downlink relay link eNB to RN, and DL subframes [7, 8, 9] are all MBSFN subframes, these The first 1, 2 or 3 OFDMsymbols of each subframe in the downlink subframe are unicast parts, and the remaining time is used for relay link transmission between RN and eNB, and guard time (as shown in pattern AC). The unicast of DL subframe 8 is used to send DL pilot, and the control channel, PCFICH, PHICH, unicast of DL subframe 7 and DL subframe 8 are used to send DL pilot.

In the frame structure proposed in Embodiment 7 of the present invention, the original downlink subframe used for the UL or DL relay link may also be an MBSFN subframe in the LTE/LTE-ATDD system, and the unicast of the MBSFN subframe part, used to send DL pilot, and/or control signaling, such as control channel, PCFICH, PHICH, the remaining time is used for relay link transmission between RN and eNB, and guard time, this method is also applicable As for the situation of other matching ratios, no more details are given here.

In all the above-mentioned embodiments, the guard time of the relay subframe includes the guard time of the downlink relay subframe and the guard time of the uplink relay subframe. For the guard time of the downlink relay subframe, such as subframe 7 and subframe 7 in FIG. 7 Frame 8, when the transmission time (idle time) is greater than the conversion time (the conversion time between RN’s reception and transmission or transmission to reception), for the relay frame where RN is located, taking subframe 7 where Psubframe is located as an example, the subframe needs to be The guard time within a frame is divided into 2 parts. The guard time RGPf before the Psubframe (the front part of the relay guard time) and the guard time RGPb after the Psubframe (the rear part of the relay guard time), the guard time RGPf before the Psubframe = transmission time (transmission time from RN to eNB, hereinafter referred to as transmission time), the protection time behind Psubframe = the conversion time from sending to receiving by RN (hereinafter referred to as RN conversion time); in Figure 7, the relay subframe 7 corresponding to the relay frame where the eNB is located, RGPf=0, RGPb= Transmission time + RN receiving and sending switching time (hereinafter referred to as RN switching time). In all the above-mentioned embodiments, the method of selecting the guard time when the DL subframe is used as the relay subframe is the same. When the transmission time is less than the switching time, in the relay subframe 7 of the relay frame where the RN is located, RGPf=RN switching time, RGPb=RN switching time. Corresponding to the relay subframe 7 corresponding to the relay frame where the eNB is located, RGPf=0, RGPb=the sum of the RN switching time and the RN switching time.

The guard time of the uplink relay subframe includes the guard time of the downlink subframe used as the UL relay subframe and the guard time of the uplink subframe used as the uplink relay subframe. For the downlink subframe used as the guard time of the UL relay subframe, such as subframe 9 in Figure 9, when the transmission time is greater than the transition time, in subframe 9 of the RN relay frame, RGPf=RN transition time, RGPb=transmission Time; in subframe 9 of the eNB relay frame, RGPf=RN switching time+transmission time, RGPb=0. When the transmission time is less than the switching time, in subframe 9 of the RN relay frame, RGPf=RN switching time, RGPb=switching time; in subframe 9 of the eNB relay frame, RGPf=RN switching time+transmission time, RGPb= Conversion time - transfer time. For the uplink subframe, the guard time of the uplink relay subframe is used, such as subframe 3 in FIG. 7 . When the transmission time is greater than the switching time, in subframe 3 of the RN relay frame, RGPf=RN switching time, RGPb=transmission time; in subframe 3 of the eNB relay frame, RGPf=RN switching time+transmission time, RGPb= 0. When the transmission time is less than the switching time, in subframe 3 of the RN relay frame, RGPf=RN switching time, RGPb=switching time; in subframe 3 of the eNB relay frame, RGPf=RN switching time+transmission time, RGPb= Conversion time - transfer time.

The above guard time consisting of any one or more of conversion time, transmission time and idle time can also be adjusted by both sending parties in signaling such as timing adjustment without being expressed in the frame structure.

Embodiment 8 of the present invention also proposes a communication device, as shown in FIG. 16 , including: a selection module 151 for selecting a subframe in a TDD relay frame as a subframe of a relay link, and the selection of the TDD relay The subframe in the frame as the relay link subframe includes: selecting the downlink subframe in the TDD relay frame as the downlink relay link subframe, and/or selecting the downlink subframe in the TDD relay frame as the uplink relay link and/or select the uplink subframe in the TDD relay frame as the uplink relay link subframe; the transmission module 152 is configured to perform relay transmission according to the relay link subframe selected by the module 151.

When performing relay transmission according to the selected relay link subframe, if the downlink subframe in the relay frame is used as an uplink relay link subframe or a downlink relay link subframe, select the previous subframe in the downlink subframe N OFDM symbols are transmitted as the relay and the UE under the relay, or as the access link between the base station and the UE under the base station, and are used to send downlink pilots, or downlink pilots and control signaling, the The remaining OFDM symbols in the downlink subframe are used as relay link transmission and/or guard time, that is, the time except the first N OFDM symbols in the downlink subframe is used as relay link transmission and/or guard time .

There are M OFDM symbols in the downlink subframe, the M and N are natural numbers, and N is smaller than M.

The solutions provided by the embodiments of the present invention can be applied to LTE, LTEAdvanced, various versions of LTE (Rel-8, Rel-9, Rel-10, etc.), World Interoperability for Microwave Access (WiMax), ultra-wideband wireless communication ( Ultra-Wideband, UMB) and other systems.

In the embodiment of the present invention, the LTE/LTE-A system is taken as an example for illustration. Further, the selection module 151 includes:

The first selecting unit 1511 is configured to select subframe 3 as an uplink relay link subframe, and select subframe 7 and subframe 8 as downlink subframes when the ratio of downlink subframes to uplink subframes is 6:3. Relay link subframe; or select subframe 3 as uplink relay link subframe, select subframe 7, subframe 8 and subframe 9 as downlink relay link subframe; or select subframe 7 as downlink For the relay link subframe, select subframe 9 as the uplink relay link subframe; or select subframe 7 as the uplink relay link subframe, and select subframe 9 as the downlink relay link subframe; or Select subframe 7 as the subframe for the downlink relay link, select subframe 8 as the subframe for the uplink relay link; or select subframe 7 as the subframe for the uplink relay link, and select subframe 8 as the subframe for the downlink Relay link subframes; or select one or more of the subframes [3, 7, 8, 9] as downlink relay link subframes, and the remaining subframes as uplink relay link subframes , the number of subframes used as an uplink relay link is greater than or equal to 1, and subframe 3 can only be used as an uplink relay link subframe.

The second selection unit 1512 is configured to select subframe 4 as a downlink relay link subframe and select subframe 9 as an uplink relay link when the ratio of the downlink subframe to the uplink subframe is 3:1 or select subframe 4 as the subframe for the uplink relay link, and select subframe 9 as the subframe for the downlink relay link; or select one of the subframes [3, 4, 8, 9] or more are used as downlink relay link subframes, and the rest are used as uplink relay link subframes, and the number of uplink relay link subframes is greater than or equal to one.

The third selecting unit 1513 is configured to select subframe 4 as a downlink relay link subframe and select subframe 7 as an uplink relay link when the ratio of the downlink subframe to the uplink subframe is 7:2 or select subframe 4 as the subframe for the uplink relay link, and select subframe 7 as the subframe for the downlink relay link; or select one of the subframes [4, 7, 8, 9] or more are used as downlink relay link subframes, and the rest are used as uplink relay link subframes, and the number of uplink relay link subframes is greater than or equal to one.

The fourth selecting unit 1514 is configured to select subframe 9 as a downlink relay link subframe and select subframe 3 as an uplink relay link when the ratio of the downlink subframe to the uplink subframe is 2:2 or select subframe 4 as the subframe for the downlink relay link, and select subframe 8 as the subframe for the uplink relay link; or select subframe 4 and subframe 9 as the subframe for the downlink relay link , select subframe 3 and subframe 8 as uplink relay link subframes; or select one or more of subframes [3, 4, 8, 9] as downlink relay link subframes, and the rest The subframe is used as an uplink relay link subframe, the number of uplink relay link subframes is greater than or equal to one, and subframe 3 and subframe 8 can only be used as uplink relay link subframes.

The fifth selecting unit 1515 is configured to select subframe 9 as a downlink relay link subframe and select subframe 4 as an uplink relay link when the ratio of the downlink subframe to the uplink subframe is 3:5 path subframe.

The sixth selecting unit 1516 is configured to select one or more of the subframes [3, 4, 7, 8, 9] for use when the ratio of the downlink subframe to the uplink subframe is 8:1. The subframes for the downlink relay link, and the rest are used as uplink subframes for the relay link, and the number of subframes used for the uplink relay link is greater than or equal to one.

The communication device in the embodiment of the present invention can apply the above-mentioned method embodiments. Through the embodiment of the present invention, the communication device selects subframes that can be used for relay link transmission when performing data transmission, and uses the relay link for data transmission. The data transmission conforms to the inherent constraints of the TDD frame structure in the prior art, and the system using the TDD relay frame is covered and extended, so that the throughput is enhanced.

Through the above description of the implementation manners, those skilled in the art can clearly understand that the present invention can be realized by hardware, or by software plus a necessary general hardware platform. Based on this understanding, the technical solution of the present invention can be embodied in the form of software products, which can be stored in a non-volatile storage medium (which can be CD-ROM, U disk, mobile hard disk, etc.), including several The instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute the methods described in various embodiments of the present invention.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (15)

1. A method for relay transmission, characterized in that, when the LTE/LTE-A relay frame is TDD uplink/downlink ratio TDDUL/DLConfiguration3 in the LTE/LTE-A system, in the LTE/LTE-A The subsequent frame includes 10 subframes with subframe indexes from 0 to 9, where subframe 1 is a special subframe, subframes 0, 5, 6, 7, 8, and 9 are downlink subframes, and subframes 2, 3, and 4 are An uplink subframe, the special subframe includes a downlink pilot time slot, an uplink pilot time slot and a guard time; The evolved base station eNB performs relay transmission with the RN on the downlink relay link from the eNB to the relay station RN; The eNB performs relay transmission with the RN on the uplink relay link from the RN to the eNB; Wherein, subframe 3 in the LTE/LTE-A relay frame is selected as the uplink relay link subframe, and subframe 7 and subframe 8 are selected as the downlink relay link subframe; or, subframe 3 is selected as the uplink relay link subframe; Selected as the uplink relay link subframe, subframe 7, subframe 8 and subframe 9 are selected as the downlink relay link subframe; or, subframe 7 is selected as the downlink relay link subframe, and subframe 9 is selected as the downlink relay link subframe; Selected as the subframe of the uplink relay link; or, subframe 7 is selected as the subframe of the uplink relay link, and subframe 9 is selected as the subframe of the downlink relay link; or, subframe 7 is selected as the subframe of the downlink relay link In the relay link subframe, subframe 8 is selected as the uplink relay link subframe; or, subframe 7 is selected as the uplink relay link subframe, and subframe 8 is selected as the downlink relay link subframe. 2. The method according to claim 1, further comprising: selecting the first N OFDM symbols in the downlink relay link subframe as the relay station and the user equipment served by the relay station The access link transmission between the base station and the user equipment served by the base station is used to send the downlink pilot, or the downlink pilot and control signaling, and the downlink relay link subframe There are M OFDM symbols in , the M and N are natural numbers, and N is smaller than M. 3. The method according to claim 2, wherein said N is 1, 2, 3 or 4. 4. The method according to claim 1, 2 or 3, wherein the downlink relay link subframe is configured as a multicast multicast single frequency network (MBSFN) subframe. 5. An evolved base station eNB, characterized in that, when the LTE/LTE-A relay frame is TDD uplink/downlink ratio TDDUL/DLConfiguration3 in the LTE/LTE-A system, the LTE/LTE-A relay frame Including 10 subframes with subframe indexes from 0 to 9, where subframe 1 is a special subframe, subframes 0, 5, 6, 7, 8, and 9 are downlink subframes, and subframes 2, 3, and 4 are uplink subframes frame, the special subframe includes downlink pilot slots, uplink pilot slots and guard time; the eNB includes: means for relaying transmissions with the RN on a downlink relay link from the eNB to the relay station RN; and means for relaying transmissions with the RN on an uplink relay link from the RN to the eNB; Wherein, subframe 3 in the LTE/LTE-A relay frame is selected as the uplink relay link subframe, and subframe 7 and subframe 8 are selected as the downlink relay link subframe; or, subframe 3 is selected as the uplink relay link subframe; Selected as the uplink relay link subframe, subframe 7, subframe 8 and subframe 9 are selected as the downlink relay link subframe; or, subframe 7 is selected as the downlink relay link subframe, and subframe 9 is selected as the downlink relay link subframe; Selected as the subframe of the uplink relay link; or, subframe 7 is selected as the subframe of the uplink relay link, and subframe 9 is selected as the subframe of the downlink relay link; or, subframe 7 is selected as the subframe of the downlink relay link In the relay link subframe, subframe 8 is selected as the uplink relay link subframe; or, subframe 7 is selected as the uplink relay link subframe, and subframe 8 is selected as the downlink relay link subframe. 6. The eNB according to claim 5, wherein the first N OFDM symbols in the downlink relay link subframe are selected as the access link transmission between the relay station and the user equipment served by the relay station, or The access link transmission between the base station and the user equipment served by the base station is used to send downlink pilots, or downlink pilots and control signaling, there are M OFDM symbols in the downlink relay link subframe, and the M and N are natural numbers, and N is smaller than M. 7. A relay station RN, characterized in that, when the LTE/LTE-A relay frame is TDD uplink/downlink ratio TDDUL/DLConfiguration3 in the LTE/LTE-A system, the LTE/LTE-A relay frame includes 10 subframes with subframe indexes from 0 to 9, where subframe 1 is a special subframe, subframes 0, 5, 6, 7, 8, and 9 are downlink subframes, and subframes 2, 3, and 4 are uplink subframes , the special subframe includes a downlink pilot time slot, an uplink pilot time slot and a guard time; the RN includes: means for performing relay transmission with the eNB on the downlink relay link from the evolved base station eNB to the relay station RN; and means for relaying transmissions with the eNB on an uplink relay link from the RN to the eNB; Wherein, subframe 3 in the LTE/LTE-A relay frame is selected as the uplink relay link subframe, and subframe 7 and subframe 8 are selected as the downlink relay link subframe; or, subframe 3 is selected as the uplink relay link subframe; Selected as the uplink relay link subframe, subframe 7, subframe 8 and subframe 9 are selected as the downlink relay link subframe; or, subframe 7 is selected as the downlink relay link subframe, and subframe 9 is selected as the downlink relay link subframe; Selected as the subframe of the uplink relay link; or, subframe 7 is selected as the subframe of the uplink relay link, and subframe 9 is selected as the subframe of the downlink relay link; or, subframe 7 is selected as the subframe of the downlink relay link In the relay link subframe, subframe 8 is selected as the uplink relay link subframe; or, subframe 7 is selected as the uplink relay link subframe, and subframe 8 is selected as the downlink relay link subframe. 8. The RN according to claim 7, wherein the first N OFDM symbols in the downlink relay link subframe are selected as the access link transmission between the relay station and the user equipment served by the relay station, or The access link transmission between the base station and the user equipment served by the base station is used to send downlink pilots, or downlink pilots and control signaling, there are M OFDM symbols in the downlink relay link subframe, and the M and N are natural numbers, and N is smaller than M. 9. A method for relay transmission, comprising: Select the subframe in the time division duplex TDD relay frame as the relay link subframe, the TDD relay frame is the LTE/LTE-ATDD relay frame, when the LTE/LTE-A relay frame is the LTE/LTE- When the TDD uplink/downlink configuration is TDD UL/DLConfiguration3 in system A, the LTE/LTE-A relay frame includes 10 subframes with subframe indexes from 0 to 9, where subframe 1 is a special subframe, subframe 0, 5, 6, 7, 8 and 9 are downlink subframes, subframes 2, 3 and 4 are uplink subframes, and the special subframes include downlink pilot time slots, uplink pilot time slots and guard time; The selection of the subframe in the TDD relay frame as the relay link subframe includes: selecting subframe 3 as the uplink relay link subframe, and selecting subframe 7 and subframe 8 as the downlink relay link subframe ; Or, select subframe 3 as the uplink relay link subframe, select subframe 7, subframe 8 and subframe 9 as the downlink relay link subframe; or, select subframe 7 as the downlink relay link For subframes, subframe 9 is selected as an uplink relay link subframe; or, subframe 7 is selected as an uplink relay link subframe, and subframe 9 is selected as a downlink relay link subframe; or, selected Subframe 7 is used as the subframe of the downlink relay link, and subframe 8 is selected as the subframe of the uplink relay link; or, subframe 7 is selected as the subframe of the uplink relay link, and subframe 8 is selected as the subframe of the downlink Relay link subframe; Perform relay transmission according to the relay link subframe. 10. The method according to claim 9, further comprising: selecting the first N orthogonal frequency division multiplexing (OFDM) symbols in the subframe of the downlink relay link as the link between the relay station and the user equipment served by the relay station. The access link transmission of the base station, or the access link transmission between the base station and the user equipment served by the base station, is used to send the downlink pilot, or the downlink pilot and control signaling, and the downlink relay link subframe There are M OFDM symbols, M and N are natural numbers, and N is smaller than M. 11. The method of claim 9 or 10, wherein, The performing relay transmission according to the relay link subframe includes: performing communication between the base station and the user equipment served by the base station according to the relay link subframe; and/or performing communication between the base station and the relay station according to the relay link subframe; and/or Perform communication between the relay station and the user equipment served by the relay station according to the relay link subframe. 12. The method according to claim 10, wherein said N is 1, 2, 3 or 4. 13. The method according to claim 9, 10 or 12, wherein the downlink relay link subframe is configured as a multicast multicast single frequency network (MBSFN) subframe. 14. A communication device, characterized in that it comprises: A selection module, configured to select a subframe in a time division duplex TDD relay frame as a relay link subframe; A transmission module, configured to perform relay transmission according to the relay link subframe selected by the selection module; The selection module includes a first selection unit, which is used for when the frame structure of the TDD relay frame is the TDD frame structure of the TDD uplink/downlink ratio TDDUL/DLConfiguration3 in the LTE/LTE-A system, the LTE/LTE -A relay frame includes 10 subframes with subframe indexes from 0 to 9, where subframe 1 is a special subframe, subframes 0, 5, 6, 7, 8, and 9 are downlink subframes, and subframes 2 and 3 and 4 are uplink subframes, the special subframes include downlink pilot time slots, uplink pilot time slots and guard time, subframe 3 is selected as an uplink relay link subframe, and subframe 7 and subframe 8 are selected for as the downlink relay link subframe; or select subframe 3 as the uplink relay link subframe, select subframe 7, subframe 8 and subframe 9 as the downlink relay link subframe; or select subframe 7 for the uplink relay link subframe; For the downlink relay link subframe, select subframe 9 as the uplink relay link subframe; or select subframe 7 as the uplink relay link subframe, and select subframe 9 as the downlink relay link subframe frame; or select subframe 7 as a downlink relay link subframe, select subframe 8 as an uplink relay link subframe; or select subframe 7 as an uplink relay link subframe, select subframe 8 Used as a downlink relay link subframe. 15. The communication device according to claim 14, wherein the selection module is used to select the first N OFDM symbols in the downlink relay link subframe as the access between the relay station and the user equipment served by the relay station Link transmission, or access link transmission between the base station and the user equipment served by the base station, is used to send downlink pilots, or downlink pilots and control signaling, and there are M in the downlink relay link subframe For an OFDM symbol, the M and N are natural numbers, and N is smaller than M.