WO2011020290A1

WO2011020290A1 - Relay method and apparatus thereof

Info

Publication number: WO2011020290A1
Application number: PCT/CN2010/001237
Authority: WO
Inventors: 张碧军; 王河; 汪勇刚; 胡中骥
Original assignee: 上海贝尔股份有限公司; 阿尔卡特朗讯
Priority date: 2009-08-17
Filing date: 2010-08-16
Publication date: 2011-02-24
Also published as: CN101997599A; CN101997599B

Abstract

The present invention discloses a relay method and an apparatus thereof. The relay method is used in half-duplex relay, and includes that: the same first symbol vector is transmitted to a relay apparatus and a reception apparatus in the a interval; a second symbol vector is transmitted to the reception apparatus in a second interval to enable the reception apparatus to obtain the first symbol vector and the second symbol vector according to a third symbol vector received in the first interval and a fourth symbol vector received in the second interval; the third symbol vector contains the first symbol vector transmitted from a transmission apparatus, and the fourth symbol vector contains the second symbol vector transmitted from the transmission apparatus and the first symbol vector forwarded from a relay apparatus. With the present invention, the full rate transmission for the symbol vectors can be realized in a half-duplex relay transmission system.

Description

Relay method and device thereof

Embodiments of the present invention generally relate to the field of wireless transmission and, more particularly, to a relay method and apparatus therefor. Background technique

In R8 of 3GPP, Multimedia Broadcast Multicast Service (MBMS), that is, single cell (SC) and multi-cell MBMS Single Frequency Network (MBSFN) transmission, is typically deployed in two scenarios.

The use of relays to expand coverage, improve capacity, and improve message edge performance has been proposed in related discussions. The hot topic of discussion is the half-duplex relay. There are two typical resource allocation methods between base stations (e-NBs) and relay devices for relays used in FDD systems. One is TD relay and the other is FD relay. The TD relay shares the same frequency resource in a time division manner for reception and transmission, and the FD relay shares the same time resource in a frequency division manner for reception and transmission.

The relay resource allocation method of time division (TD) and frequency division (FD) is shown in FIGS. 7 and 8. As shown in FIG. 7, for example, for the TD relay, the e-NB transmits the packet to the relay device and the UE in subframe 0 (other time intervals can also be configured), and the relay device forwards the packet in different subframes 1 ( According to the type of the relay, it is directly forwarded or decoded and then forwarded after receiving. As shown in Figure 8, for example, for FD relay, the e-NB sends the packet to the relay in radio bearer 0 (which can also be configured with other granularity). The device and the UE, the relay device uses different frequency resources, such as RB-1, to send the packet to the UE.

In other words, the relay device receives and transmits packets on different frequency resources. Regardless of which method is used for the half-duplex relay, there is an inherent delay between the relay device and its service e-NB since the reception and transmission at the relay device cannot be performed simultaneously. This situation is illustrated in detail in Figure 9. As shown in Figure 9, in order to avoid interference from the serving e-NB, the relay device sends a packet on subframe 1, such as pl, the service e-NB usually remains silent or simply sends the same packet (such as pi) to It is also possible for those UEs that receive the packet from the serving e-NB. Therefore, a valid packet (e.g., pi) is transmitted to the UE on two slots (subframe 0 and subframe 1). In other words, for this half-duplex relay transmission system, up to half rate is obtained.

However, there is no solution for obtaining a full rate MBMS after the introduction of a half duplex relay. Summary of the invention

Embodiments of the present invention propose a relay method and apparatus therefor.

According to an aspect of the present invention, a relay method for use in a half-duplex relay is provided, the method comprising: transmitting the same first symbol vector to a relay device and a receiving device at a first time interval; Sending a second symbol vector to the receiving device at a second time interval, such that the receiving device acquires the first symbol according to the third symbol vector received on the first time interval and the fourth symbol vector received on the second time interval And a second symbol vector, where the third symbol vector includes a first symbol vector sent by the transmitting device, where the fourth symbol vector includes a second symbol vector sent by the transmitting device and a first symbol vector forwarded by the relay device.

According to another aspect of the present invention, a transmitting device is further provided, the transmitting device comprising a processing unit, configured to instruct to send the same first symbol vector to the relay device and the receiving device at the first time interval, in the second Sending a second symbol vector to the receiving device at a time interval, such that the receiving device acquires the first symbol vector according to the third symbol vector received at the first time interval and the fourth symbol vector received at the second time interval And a second symbol vector, where the third symbol vector includes a first symbol vector indicated by the processing unit, and the fourth symbol vector includes a second symbol vector indicated by the processing unit and the first symbol vector forwarded by the relay device; And a transceiver unit, configured to send the first symbol vector and the second symbol vector according to the indication of the processing unit.

According to still another aspect of the present invention, a relay device is further provided, the relay device includes a receiving unit, configured to receive a first symbol vector sent by the transmitting device at a first time interval, and a sending unit, configured to Transmitting, to the receiving device, the first symbol vector received by the receiving unit on the second time interval, so that the receiving device receives the third symbol vector received on the first time interval and the fourth symbol vector received on the second time interval Obtaining a first symbol vector and a second symbol vector, where the third symbol vector includes a first symbol vector sent by the sending device, where the fourth symbol vector includes a second symbol vector sent by the sending device and a first symbol vector sent by the sending unit.

According to still another aspect of the present invention, a receiving device is provided, the receiving device comprising: a receiving device transceiver unit, configured to receive a third symbol vector from a transmitting device at a first time interval and to relay from a second time interval The device receives the fourth symbol vector; the symbol regenerating unit is configured to acquire, according to the third symbol vector and the fourth symbol vector, the first symbol vector and the second symbol vector sent by the sending device, where the third symbol vector includes the sending by the sending device A symbol vector, the fourth symbol vector includes a second symbol vector transmitted by the transmitting device and a first symbol vector forwarded by the relay device. According to still another aspect of the present invention, a system including the above-described transmitting device, relay device, and receiving device is also proposed.

With the above technical solution, the symbol vector is directly transmitted to the mobile terminal in the second time interval (such as the second subframe) without passing through the relay device, and the signal passing through the relay device is not relayed at the mobile terminal. The signal of the device is processed to restore the symbol vectors respectively transmitted in each time interval, thereby obtaining full rate transmission of the symbol vector in the half duplex relay transmission system. DRAWINGS

The invention will be better understood by the following detailed description of embodiments of the invention, wherein: FIG.

2 shows a block diagram of a base station according to an embodiment of the present invention;

FIG. 3 shows a block diagram of a relay device according to an embodiment of the present invention; FIG.

4 shows a block diagram of a mobile terminal in accordance with an embodiment of the present invention;

FIG. 5 shows a flow chart of a relay method according to an embodiment of the present invention;

FIG. 6 is a schematic diagram showing subframe occupation of symbol vector transmission according to an embodiment of the present invention; FIG.

FIG. 7 is a schematic diagram showing resource allocation in the case of time division multiplexing in the prior art;

FIG. 8 is a schematic diagram of resource allocation in the case of frequency division multiplexing in the prior art;

FIG. 9 is a schematic diagram showing the occupation of a subframe by symbol vector transmission in the prior art. Specific embodiment

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, and the details and functions that are not necessary for the present invention are omitted in the description to avoid confusion of the understanding of the present invention.

An embodiment of the present invention provides a system for half-duplex relay transmission. As shown in FIG. 1, the following includes a sending device, a relay device, and a receiving device, where the sending device and the receiving device are respectively a base station and a mobile device. terminal.

An embodiment of the present invention further provides a transmitting device. As shown in FIG. 2, the sending device includes a processing unit 210, configured to indicate that the same first symbol vector is sent to the relay device and the receiving device at the first time interval. Transmitting, to the receiving device, a second symbol vector on the second time interval, such that the receiving device obtains according to the third symbol vector received on the first time interval and the fourth symbol vector received on the second time interval Taking a first symbol vector and a second symbol vector, where the third symbol vector includes a first symbol vector indicated by the processing unit 210, and the fourth symbol vector includes a second symbol vector indicated by the processing unit 210 and transmitted by the relay device. The first symbol vector; the transmitting device transceiver unit 220 is configured to send the first symbol vector and the second symbol vector according to the instruction of the processing unit 210.

The sending device transceiver unit 220 is further configured to receive information about the channel reported by the receiving device. The sending device further includes an encoding unit 230, configured to perform encoding according to the information about the channel.

The transmitting device also includes an encoding information memory 240 for storing information about the channel received by the transmitting device transceiving unit 220 and other information required for encoding, such as code words corresponding to various encodings.

The transmitting device also includes a symbol generation unit 250 for generating an original symbol vector for encoding unit 230 to encode as needed.

An embodiment of the present invention further provides a relay device, as shown in FIG. 3, including a receiving unit 310, configured to receive a first symbol vector sent by a sending device at a first time interval, and a sending unit 320, configured to Transmitting, by the receiving device, a symbol vector received by the receiving unit 310 on the second time interval, such that the receiving device receives the third symbol vector received on the first time interval and the fourth symbol vector received on the second time interval. Obtaining a first symbol vector and a second symbol vector, where the third symbol vector includes a first symbol vector sent by the sending device, where the fourth symbol vector includes a second symbol vector sent by the sending device and the first symbol sent by the sending unit 320. The apparatus also includes a power control unit 330 for adjusting the received symbol vector over the first time interval to ensure that the average transmit power of the transmitting unit 320 is constant.

The relay device further includes a power control policy library 340 for storing a pre-set power control policy for the power control unit 330 to use. For example, the power control strategy can include a plurality of power levels, and the power control unit 330 can select one of the power levels as the average transmit power of the signal transmitted by the transmitting unit 320. The power level may be a plurality of actual power values, or may be in the form of half power, 1/4 power, or the like of a certain maximum power value.

The embodiment of the present invention further provides a receiving device, including a receiving device transceiver unit 410, configured to receive a third symbol vector on a first time interval and receive a fourth symbol vector on a second time interval; the symbol regeneration unit 420 And acquiring, by the third symbol vector and the fourth symbol vector received by the receiving device transceiver unit 410, the first symbol vector and the second symbol vector sent by the sending device, where the third symbol vector includes the first symbol sent by the sending device. Vector, the fourth symbol vector contains the second symbol vector and the medium sent by the transmitting device The first symbol vector that is forwarded by the device.

According to an embodiment of the present invention, the receiving device further includes an information collecting unit 440, configured to collect information of a channel between the receiving device and the transmitting device in real time or indirectly, and the channel feedback unit 430 is configured to report the data through the receiving device transceiver unit 410. The information about the channel collected by the information collecting unit 440 is facilitated by the transmitting device to encode according to the information.

According to an embodiment of the present invention, the receiving device further includes a decoding information memory 450 for storing decoding information corresponding to the encoding information stored by the encoding information memory of the transmitting device (eg, the decoding codeword and/or information collecting unit 440 collects Information about the channel). When encoding occurs in the transmitting device, the symbol reproducing unit 420 decodes the received symbol vectors (e.g., the third symbol vector and the fourth symbol vector) using the decoding information stored in the decoding information memory 450.

Although the transmitting device, the relay device, and the receiving device of the embodiments of the present invention have been described above in the form of separate functional modules, each of the components shown in FIGS. 2 to 4 can be implemented by a plurality of devices in practical applications. The various components shown can also be integrated in a single chip or a device in practical applications. The transmitting device, the relay device, and the receiving device may also include any unit and device for other purposes.

The specific structure and operation process of the above-mentioned transmitting device, relay device and receiving device will be described in detail below with reference to Figs. 5 and 6. For the sake of clarity, in the following description of the specific embodiments, the description is made with the base station as the transmitting device and the mobile terminal as the receiving device. However, it will be apparent to those skilled in the art that the transmitting device can also be a mobile terminal and the receiving device can be a base station.

Embodiments of the invention may be used in the following exemplary application scenarios:

Deployment scenario: The relay device is located in the SFN area and the UE can receive signals from all serving e-NBs and relay them at the same time. For UEs located at the edge of the SFN area or at the center of a single frequency network (SFN) edge cell with strong fading, the signal power received from the relay device may be stronger than the signal power received from the serving e-NB.

The number of hops, the maximum number of hops is 2, that is, the service e-NB→relay device-UE. For the sake of brevity, only the downlink for MBMS is considered.

Wireless link: The link between the service e-NB and the relay device is wireless.

Fixed relay: From the perspective of the UE, the relay is fixed.

In-band relay transmission: That is, the service e-NB→UE and the service relay device share the same downlink frequency band. The aforementioned TD half-duplex relay and FD half-duplex relay are both in-band relays. For the sake of brevity, the following The TD half-duplex relay is used in the description.

LI AF (Amplified Forwarding Mode) Relay or L2 DF (Decode Forwarding Mode) Relay: Both can be assumed to be AF relays.

Extension: This is assumed to be MBSFN. It is easy to find that when the data of the serving e-NB is 1, this scenario is equivalent to SC MBMS, and when the number of UEs in SC MBMS is 1, this scenario is equivalent to unicast. .

FIG. 5 is a relay method according to an embodiment of the present invention. As shown in FIG. 5, in step 510, a first symbol vector XI is transmitted to the relay device and the mobile terminal on the first subframe.

It is assumed that there are a total of G serving base stations e-NB and a randomly received mobile terminal C/Ez' in the MBSFN. The analysis at the other UEs is also the same.

In Fig. 6, Χ2, Γ, and are column vectors of length Ν. Specifically, AND is the transmitted symbol vector of length Ν, that is, the first symbol vector and the second symbol vector described above. F is the symbol vector received by the relay device. And Ζ2 are the vectors of length Ν received, that is, the third symbol vector and the fourth symbol vector described above, respectively.

Since SFN operation is performed for MBMS, it is first assumed that all e-NBs have a single transmit antenna. For simplicity, it is assumed that a single antenna is also used at the relay device and UEi, but in some embodiments of the invention it is not limited to using only one antenna. If it is a multi-antenna scenario, such as multiple input multiple output antenna (MIMO), in the embodiment of the present invention, as long as the relay device and the UE configure the required antenna, such as in 2x2 MIMO, the relay device and The UE configures two antennas, and 2x1 MIMO only needs to configure one antenna in the relay device and the UE.

The channel between all e-NBs and relays is modeled as /?, i = 1, ..., G (assuming a total of G eNBs). The channel between the relay device and UEi is modeled as g. Model the channel between all e-NBs and UEi as

..., G. These channels are all modeled independently of the same distribution (i.i.d.) and remain constant during a processing time interval (PTI). Without loss of generality, only one processing time interval (PTI) is considered here, for example one ΡΉ = 2 subframes. It is assumed that during a handover, the channel between the serving e-NB and the relay device, the channel between the relay device and the UE, the channel between the serving e-NB and the UE remain unchanged, and the channel estimation can be The model of all these channels is obtained at the UE, ie? , g and .

During the first subframe, for all e-NBs in the MBSFN, under the direction of its processing unit 210, the transmitting device transceiving unit 220 transmits the common symbol vector to the relay device and all UEs.

At this time, the signal vector received by the receiving unit 310 of the relay device is: The signal vector received by the receiving device transceiver unit 410 of the UEi is:

In (1) and (2), N and are independent and identically distributed additive white noise (AGWN), and P, i is the transmit power of the first e-NBi in the first subframe.

In step 520, a second symbol vector 2 is transmitted to the mobile terminal on the second subframe.

For all e-NBs in the MBSFN, under the direction of its processing unit 210, the transmitting device transceiving unit 220 transmits a new common symbol vector; to the bent UE. Since the half-duplex relay device is in the transmit mode at this time, the symbol vector H is not received.

Here, the sum in step 510 and step 520 may be the original symbol vector generated by the symbol generating unit 250, or the encoding unit 230 may encode one or more original symbols according to the encoding information stored in the encoding information memory 240. The resulting symbol vector.

In step 530, the power adjustment unit 330 of the relay device node adjusts the received signal vector to

Α = α · Υ (3) In (3), α denotes a power adjustment factor to ensure that the average transmit power of the relay device node is Ρ ₂ . The average transmit power Ρ ₂ can be derived from the power control strategy extracted by the power adjustment unit 330 from the power control policy library 340. The transmitting unit 320 of the relay device transmits the adjusted signal vector 到 to all UEs (including UEi) below it.

At this time, the signal vector received by the receiving device transceiver unit 410 of the UEi is:

In (4), it is an independently distributed AGWN noise, which is the transmit power of the first e-NB in the second subframe.

Thus the total transmit power during a PTI is equal to the total power limit P:

( ⁵ ) In step 540, the mobile terminal acquires the sum Ja based on the signals received from the first subframe and the second subframe.

The total signal received by the receiving device transceiver unit 410 of UEi during one PTI may be expressed as follows -

The above equation can be simplified as:

22 = -^ph~X2 + ^p gXl + W2 _{(?) For} MBSFN, assume here / _{= 2 =} ... ₌ ... ₌ J; G = and

P ₃ l ₌ P ₃ 2 = ... = P ₃ i... = P ₃ G = P ₃ , where Λ is the average transmit power of all base stations in the first subframe, and P3 is the second sub-base of all base stations The average transmit power on the frame. The symbol regeneration unit 420 can obtain _A according to the total power limit of the formula (5>, /=;,...,3, the noise power, ^ and N1 also depend on the relationship between P/, corpse ₂ and . MBSFN, = Ζ /π· and ? = «H are a composite channel from the base station to the mobile terminal and the base station to the relay device, respectively, and can be obtained by channel estimation.

According to the above settings, p corpse /, p ₂ = P ₂ , p ₃ = i, W\ = WI, ^ = g"Nl + JT2 can be derived. Equation (7) can also be simplified as follows:

In formula (8),

c^pp, i=l, 2, 3 ₀ The parameter p in equation (8) can be selected according to the actual situation. For example, the parameter p is a common coefficient extracted by making the calculation process simple.

Depending on the different structure of the transmitted complex vector, the processing of the terminal regeneration unit 420 has the following three cases - the first case: Full diversity is obtained for the two original symbol vector pairs.

Based on PEP (paired error probability) analysis, if and only if for any dissimilar original information symbol vector pair S s (where S is an estimate of S, is the symbol representing the estimate), a length 2N column vector ( - ) ( Where =[ / ^Τ Χ2 ^Τ ] ^Τ ) When there is no zero term, a full-order error codeword matrix (ie = c - ) can be obtained for any distinct codeword pair C and (where is the estimate of C). Therefore, full diversity can be achieved for the original information symbol vector ^ = [ 7 S2 ^T ]. The full diversity gain of the 2nd order can be obtained by the coding unit 230 setting = Θ^ in detail. For any non-zero vector iS-, by proper configuration of the unitary matrix, there can be no non-zero entries in the vector of length 2N. It is clear that the symbol regeneration unit 420 can decode 5 and 52 (e.g., perform sphere decoding) using the ML (Maximum Likelihood) algorithm or the simplified algorithm based on the decoded information stored in the decoding information memory 450.

Case 2: No diversity is obtained for the two original symbol pairs (without loss of generality, in OFDM, N=l is assumed here for the sake of brevity). In this case, J^[ ^T J ^T ] ^T represents the symbol vector of the original transmission, in other words, the transformation in the first case is not used. The symbols received in equation (8) can now be rewritten as:

R = ^pHC + Q (9) In the formula (9), Χ2] ^Γ because Η is the lower triangular moment

Array, DPC (dirty paper coding) can be used here. At the service e-NB, is it transmitted directly on the first subframe? . On the second subframe, once ί and 7g are known, the encoding unit 230 can pre-empt the interference from the DPC. Therefore, the symbol reproducing unit 420 of the mobile terminal can use the signal pair received on the first subframe based on the decoded information stored in the decoding information memory 450. Decoding is performed to obtain J using DPC decoding on the second sub-frame without interference.

Since the independent decoding is performed on two sub-frames, the diversity gain cannot be obtained for the two original signal pairs.

The third case: full diversity is only obtained for one original symbol, and diversity gain is not implemented for another symbol.

Unlike the second case, multi-user precoding can be used in the second subframe in this case. The coding unit 230 can effectively remove inter-stream interference by multi-user precoding, that is, on the second subframe. Interference between and J. In other words, the symbol reproducing unit 420 of the mobile terminal can first decode H according to the decoding information stored in the decoding information memory 450 and then can use the MRC (maximum ratio combining) according to the expression of the received signal on the two subframes. Decoding. Thus / obtain full diversity without obtaining diversity gain.

As can be seen from the above technical solution, during the first subframe, all the serving e-NBs transmit the common data to the relay device and all the receiving UEs. Unlike previous half-duplex relay device transmissions, all serving e-NBs transmit new common data to all UEs except for the relay device to transfer the received data to the UE during the second subframe.

From the perspective of the UE's reception, all serving e-NBs transmit independent data during one PTI (eg, a total of 2N symbols), in other words, since the e-NB is sent from the serving e-NB to the UE within 2N symbol intervals A total of 2N symbols, no loss rate.

For the three cases above, in the first case, full diversity is obtained for the two original symbol vector pairs; in the second case, no diversity is obtained for the two original symbol pairs; in the third case , only full diversity is obtained for one original symbol and no diversity is obtained for another original symbol. The above three situations The available diversity gains are different, and the corresponding signal-to-noise ratios that meet the block error rate requirements are different, and the processing complexity is different. For example, in the first case, full diversity is obtained, and the required signal-to-noise ratio is the lowest. The complexity of the second and third cases is low. In practical applications, different methods can be selected according to actual conditions (such as signal-to-noise ratio conditions).

The possible impact analysis of interface signaling (eg, signaling that supports full rate operation) is as follows:

In the first case: no uplink signaling is required, but the base station is required to indicate the presence of the relay device from the serving e-NB to the UE through the downlink signaling, whereby the UE can decode during the PTI operating.

In the second/three cases: DPC or multi-user precoding operations for the base station may require the channel feedback unit 430 of the mobile terminal to feed back some information, such as channel information, and is therefore more suitable for single cell MBMS transmission or unicast, these The information can be collected by the information collecting unit 440 and stored in the encoded information memory 240 of the base station and the decoded information memory 450 of the mobile terminal. The same downlink signaling is required to indicate the presence of a relay device for the user.

The above technical solutions are discussed for the TD mode. However, with only minor modifications, the proposed solution of the present invention can also be applied to a half-duplex relay in the FD mode. The only difference is that in the FD mode, the relay device uses different frequencies for transmission and reception.

The above technical solution is discussed for the downlink, however, the technical solution proposed by the present invention can also be used in the uplink. The only difference is that the direction of information transmission and reception is different.

Those skilled in the art will readily recognize that the different steps of the above methods can be implemented by a programmed computer. Herein, some embodiments also include a program-readable or computer-readable program storage device (eg, a digital data storage medium) and encoding machine-executable or computer-executable program instructions, wherein the instructions perform some of the above methods or All steps. For example, the program storage device can be a digital memory, a magnetic storage medium (such as a magnetic disk and magnetic tape), hardware, or an optically readable digital data storage medium. Embodiments also include a programming computer that performs the steps of the above method.

The description and drawings merely illustrate the principles of the invention. It will be appreciated that those skilled in the art are able to devise various structures, and the various structures are not described or illustrated herein. In addition, all of the examples mentioned herein are explicitly used primarily for teaching purposes to assist the reader in understanding the principles of the present invention and the concepts promoted by the inventors, and should be construed as not to the specific examples. And conditional restrictions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as the specific examples thereof, The above description is only used to implement the embodiments of the present invention, and those skilled in the art should understand that any modifications or partial substitutions of the scope of the present invention should fall within the scope defined by the claims of the present invention. The scope of the invention should be determined by the scope of the claims.

Claims

A relay method, used in a half duplex relay, the method includes:

Transmitting the same first symbol vector to the relay device and the receiving device at a first time interval; transmitting a second symbol vector to the receiving device at a second time interval, such that the receiving device is according to the first Obtaining the first symbol vector and the second symbol vector from a third symbol vector received on a time interval and a fourth symbol vector received on the second time interval, wherein the third symbol vector includes And the first symbol vector sent by the sending device, where the fourth symbol vector includes the second symbol vector sent by the sending device and the first symbol vector forwarded by the relay device.

2. The method of claim 1 further comprising:

The relay device adjusts to receive the first symbol vector on the first time interval to ensure that the average transmission power of the relay device is constant;

Transmitting the adjusted first symbol vector to the receiving device.

3. The method according to claim 1, further comprising:

Before transmitting the first symbol vector and the second symbol vector, performing dirty paper encoding according to information about the channel reported by the receiving device;

The acquiring the first symbol vector and the second symbol vector includes:

Decoding the third symbol vector to obtain the first symbol vector;

The fourth symbol vector is subjected to dirty paper decoding to obtain the second symbol vector.

4. The method according to claim 1, further comprising: using multi-user precoding on the second time interval,

The acquiring the first symbol vector and the second symbol vector includes:

Decoding the fourth symbol vector to obtain the second vector;

Decoding of multi-user precoding is performed according to the third symbol vector and the fourth symbol vector to obtain the first vector.

5. A transmitting device, comprising:

a processing unit, configured to send the same first symbol vector to the relay device and the receiving device at the first time interval, and send the second symbol vector to the receiving device at the second time interval, so that the receiving device And according to the third symbol vector received on the first time interval and on the second time interval Receiving a fourth symbol vector to obtain the first symbol vector and the second symbol vector, where the third symbol vector includes the first symbol vector indicated by the processing unit, the fourth symbol vector The symbol vector includes the second symbol vector indicated by the processing unit and the first symbol vector forwarded by the relay device;

And a sending device transceiver unit, configured to send the first symbol vector and the second symbol vector according to an indication of the processing unit.

The transmitting device according to claim 5, wherein the transmitting device transceiver unit is further configured to receive information about a channel reported by the receiving device;

The sending device further includes:

And a coding unit, configured to perform coding according to the information about the channel.

7. A relay device, comprising:

a receiving unit, configured to receive a first symbol vector sent by the sending device on the first time interval, and a sending unit, configured to send the first symbol vector received by the receiving unit to the receiving device at the second time interval, so that Receiving, by the receiving device, the first symbol vector and the sending by the sending device according to the third symbol vector received on the first time interval and the fourth symbol vector received on the second time interval a second symbol vector, where the third symbol vector includes the first symbol vector sent by the sending device, and the fourth symbol vector encapsulates the second symbol vector sent by the sending device and the The first symbol vector sent by the transmitting unit.

8. The relay device according to claim 7, further comprising:

And a power control unit, configured to adjust a symbol vector received on the first time interval to ensure that an average transmit power of the sending unit is constant.

9. A receiving device, including

a receiving device transceiver unit, configured to receive a third symbol vector on a first time interval and receive a fourth symbol vector on a second time interval;

a symbol regenerating unit, configured to acquire, according to the third symbol vector and the fourth symbol vector, a first symbol vector and a second symbol vector that are sent by the sending device, where the third symbol vector includes the sending device Transmitting the first symbol vector, where the fourth symbol vector includes the second symbol vector sent by the sending device and the first symbol vector forwarded by the relay device.

10. The receiving device according to claim 9, further comprising- And a channel feedback unit, configured to report information about the channel by the receiving device transceiver unit to facilitate the sending, by the sending device, to encode according to the information.

A system for relay communication, comprising the transmitting device according to claim 5 or 6, the relay device according to claim 7 or 8, and the receiving device according to claim 9 or 10.