WO2011038614A1

WO2011038614A1 - Downlink data transmitting method, system and relay node thereof

Info

Publication number: WO2011038614A1
Application number: PCT/CN2010/075366
Authority: WO
Inventors: 王坚
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-09-30
Filing date: 2010-07-21
Publication date: 2011-04-07
Also published as: CN102036383A

Abstract

A downlink date transmitting method, system and relay node are provided. Wherein, the method includes: an evolved node (eNB) transmits the first control information and the first downlink date to the relay node (RN) in the first sub-frame; the RN receives the first control information and the first downlink date transmitted by the eNB, transmits an answer information to the eNB in the second sub-frame, and if the reception succeeds, transmits the ACKnowledge ACK, if the reception fails, transmits the NonACKnowledge NACK; and the eNB transits the first control information to the relay termination User Equipment (UE) in the third sub-frame; in the procession that the RN receives the first control information and the first downlink data transmitted by the eNB, if the RN receives successfully, the RN distributes the first downlink data to the relay UE in the third sub-frame according to the first control message. Wherein, in the sequential relationship, the first sub-frame is before the second sub-frame, and the second sub-frame is before the third sub-frame. The technical scheme of the present invention enables distribution of the downlink data, thereby improving the throughput of the system.

Description

Downlink data transmission method and system and relay node

Technical field

The present invention relates to an advanced long-term evolution system (LTE-A, LTE-advanced) in the field of wireless communications, and more particularly to a method and system for transmitting downlink data of an LTE-A system and a relay node. Background technique

The 3rd Generation Partnership Project (3GPP) determines that the Long Term Evolution (LTE) architecture is a flattened Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (EUTRAN) architecture, and its user plane network elements mainly include user equipment (UE, User Equipment), evolved node (eNB, evolved Node B) and Serving Gateway (S-GW). The eNB and the S-GW are connected through the base station-serving gateway interface S1, and the eNBs are connected through the inter-base station interface X2, and the UE and the eNB are connected through the radio interface Uu.

To further increase capacity and coverage, 3GPP introduced a new RN (Relay Node) in the advanced version of LTE, the LTE-advanced version, as shown in Figure 2a. According to the difference in working mode, the relay node is divided into a first type (Type I) relay relay node (referred to as Type I relay) and a second type (Type II) relay relay node (referred to as Type II relay). . The Type I relay is a full-featured eNB with an independent cell identifier (cell ID). The Type I relay is an eNB with complete scheduling, and performs user management and resource scheduling for communication of the cell to which it belongs. The Type II relay is another solution for operators deploying LTE-A systems. Its main features are:

(1) The Type II relay does not have a separate cell ID, so it cannot create a new cell.

(2) The Type II relay should be able to serve the version (r) 8 UE.

(3) The R8 UE cannot perceive the existence of the Type II relay, that is, the Type II relay is transparent to the R8 UE.

(4) User management and resource scheduling exist only on the eNB, and there is no uplink and downlink scheduler on the Type II relay.

Both the first RN and the second RN are deployed between the UE and the eNB, so The communication link between the UE and the eNB is divided into two segments: The connection between the eNB and the RN is called a backhauling link, and the connection between the UE and the RN is called an access link. Correspondingly, the eNB accessed by the RN is called a Donor eNB. The UE that is directly controlled by the Donor eNB and is not related to the RN is called a Macro UE. The UE directly controlled by the RN is called a Relay UE. Relay terminal). The air interface between the UE and the RN follows the term of the air interface between the eNB and the UE in the LTE R8, and is called the Uu port, and the new interface between the Donor eNB and the Rn is called the Un interface. When the Uu interface between the original eNB and the UE is applied between the RN and the UE, the modification and improvement are not excluded, and the interface between the eNB and the RN is a completely new wireless air interface.

The new air interface Un requires the use of frequency resources. If the same band resources as the direct network-to-UE link are used, the Un interface and the Uu interface will have co-channel interference. If a different frequency band resource than the direct network-to-UE link is used, the frequency utilization is reduced, and the deployment cost of the Relay Node is increased. The former method is called an in-band method, and the latter method is called an out-band method. In the in-band mode, the following methods can be used to avoid co-channel interference. That is, the relay node performs uplink transmission on the backhauling link, and the access link does not perform uplink transmission. The downlink connection is performed on the backhauling link. No downlink reception is performed. In order to implement the above method, a special subframe mode needs to be arranged for the Relay Node. For the Type 1 Relay, the Broadcast Multicast Single Frequency Network (MBSFN) subframe mode is used, and the MBSFN subframe is used as the downlink subframe of the backhauling link, and the other subframes can be used for the downlink subframe of the access link, and the first type of Relay is used. The scheduling performance is: for the downlink data of the backhauling link, the relay can determine the time-frequency resource and the modulation mode sent to the Relay UE. For the uplink data of the access link, the relay UE can determine the scheduling request for sending data to the eNB. Therefore, in general, the backhauling link scheduling is handled by the eNB, and the access link scheduling is handled by the RN. For the Type 2 Relay, the scheduling is completely determined by the eNB, that is, the scheduling of the backhauling link and the access link can be determined, and is implemented by the eNB according to the unified implementation. In this case, the eNB will uniformly consider the backhauling link and the access link scheduling, and complete the uplink and downlink cooperation. Transmission: The eNB allocates resources for the UE (including the Relay UE and the Macro UE). To avoid the same-frequency interference, the relay uses the time division multiplexing mode. When the Relay receives the backhauling data, the eNB does not send data to the Relay UE, and the eNB is in the relay. When the UE transmits data, the eNB does not send backhauling data to the Relay. That is, in some subframes, the eNB allocates resources for the Relay and Macro UEs without allocating resources for the Relay UE; and in other subframes, the eNB allocates resources for the Relay UE and the Macro UE without allocating resources for the Relay. . However, there is no specific implementation plan for how to implement downlink data transmission.

Summary of the invention

The technical problem to be solved by the present invention is to provide a downlink data transmission method and system and a relay node to implement downlink data transmission and increase system throughput.

To solve the above technical problem, the present invention provides a downlink data sending method, and the method includes:

The evolved node BeNB sends the first control information and the first downlink data to the relay node RN in the first subframe;

The RN receives the first control information and the first downlink data sent by the eNB, and sends the response information to the eNB in the second subframe, if the RN receives the first control information and the first downlink data successfully. Sending a positive acknowledgement ACK, and if the RN fails to receive the first control information and the first downlink data, sending a negative acknowledgement NACK;

The eNB sends the first control information to the relay terminal UE in the third subframe, and in the step that the RN receives the first control information and the first downlink data sent by the eNB, if the RN receives After the first control information and the first downlink data are successful, the RN sends the first downlink data to the relay UE in the third subframe according to the first control information; The first subframe is preceded by the second subframe, and the second subframe is preceded by the third subframe.

Preferably, in the step of transmitting the response information to the eNB in the second subframe, if the response information sent by the RN is a positive response, the eNB sends the eNB to the relay terminal UE in the third subframe. After the step of the first control information, the method further includes:

The eNB sends the second control information to the RN in the fourth subframe. If the response information sent by the RN is a negative response, the eNB sends the second control information to the RN in the fourth subframe. The second downlink data, wherein the third subframe precedes the fourth subframe in a timing relationship. Preferably, the first control information is the same as or partially different from the second control information, and the first downlink data is the same as the second downlink data, and the parts are the same or different.

Preferably, in the step of the eNB transmitting the first control information to the relay terminal UE in the third subframe, When the frequency resources used by the relay UEs belonging to different RNs are different, the eNB sends the first downlink data to the relay UE while the first subframe transmits the first control information.

Preferably, the interval between the third subframe and the first subframe is greater than or equal to 4 ms.

Preferably, in the step of the RN sending the response information to the eNB in the second subframe, if the response information sent by the RN is a positive response, the eNB sends the fourth subframe to the RN. The second control information, after the step that the eNB sends the second control information and the second downlink data to the RN in the fourth subframe, if the response information sent by the RN is a negative response, the method further includes:

The relay UE sends the response information to the eNB in the fifth subframe. If the response message is a positive response, the process ends. If the response message is a negative response, the second subframe to the fifth subframe are repeatedly executed. The operation on the frame until the end of the process; wherein, in the timing relationship, the fourth subframe precedes the fifth subframe.

To solve the above technical problem, the present invention also provides a downlink data transmission method, and the method includes:

a. In the nth subframe, the eNB sends a relay terminal (Relay) to the relay node (RN)

First control information and first downlink data of the UE;

b. In the (n+4)th subframe, the RN sends a response message to the eNB, and if the reception succeeds, sends an acknowledgement (ACK), otherwise sends a negative acknowledgement (NACK);

In the mth subframe, the eNB sends the first control information to the Relay UE. If the receiving succeeds, the RN sends the first downlink data to the Relay UE, where n+4<m<n+ 8: d, in the (n+8)th subframe, if the RN response information in step c is an acknowledgement (ACK), the eNB sends the second control information to the RN, otherwise sends the second control information to the RN. Second downlink data;

e, the m+4th subframe, the Relay UE receives the sent response information to the eNB, and if the receiving is successful, sends a positive acknowledgement (ACK), the process ends, otherwise, a negative acknowledgement (NACK) is sent to modify n=n+8 , m=m+8 , loop through steps b to e until the end of the process.

Preferably, the first control information is the same as or the same as the second control information, and the first downlink data is the same as the second downlink data, and the parts are the same or different. Preferably, the eNBs in the step c are simultaneously transmitting the first downlink data to the Relay UE in the mth subframe.

To solve the above technical problem, the present invention further provides a downlink data transmission system, where the system includes an evolved Node B (eNB) and a relay node RN, where

The eNB is configured to: send first control information and first downlink data for the relay terminal UE to the RN in the first subframe; and send the first control information to the relay UE in the third subframe. ;

The RN includes a receiving module, a determining module, and a sending module, which are sequentially connected, where the receiving module is configured to receive first control information and first downlink data sent by the eNB;

The determining module is configured to determine whether the first control information and the first downlink data are correctly received;

The sending module is configured to: when determining that the first control information and the first downlink data are received correctly, send an acknowledgement to the eNB in a second subframe, and in a third subframe according to the first control information The relay terminal sends the first downlink data; when it is determined that the first control information and the first downlink data are failed to be received, a negative acknowledgement is sent to the eNB in the second subframe;

The first subframe precedes the second subframe and the second subframe precedes the third subframe in a timing relationship.

Preferably, the eNB is further configured to: receive the response information sent by the RN, and when the response information is a positive response, send the second control information to the RN in the fourth subframe, where the response information is a negative response. The second control information and the second downlink data are sent to the RN in the fourth subframe.

Preferably, the eNB is further configured to: when the frequency resources used by the relaying UEs belonging to different RNs are different, send the first downlink data to the Relay the UE.

To solve the above technical problem, the present invention provides a relay node RN, where the RN is configured to receive first control information and first downlink data sent by the evolved Node B, and determine the first control information and the first Whether the downlink data is correctly received, if the first control information and the first downlink data are If the packet is received correctly, the first downlink data is sent to the relay terminal in the third subframe according to the first control information.

In the downlink data transmission method and system of the present invention, the eNB sends the control information and the downlink data to the RN in the first subframe, the RN sends the response information to the eNB in the second subframe, and the eNB sends the control to the Relay UE in the third subframe. The RN sends the downlink data to the Relay UE in the third subframe, so that the downlink data is delivered, and the throughput of the system is increased. In addition, if interference occurs between the RNs, the eNB may send downlink data to the Relay UE in addition to the downlink control information in the third subframe, which may enhance the UE signal strength; if the distance between the RNs is far away, no interference occurs. The eNB sends only the control information to the Relay UE, and the different RNs transmit the downlink data to the associated Relay UE on the same frequency resource, thereby implementing multiplexing of the frequency resources. BRIEF abstract

1 is a flow chart of downlink data transmission of the present invention.

2a is a schematic diagram of frequency band allocation of a backhualing subframe in the cooperative transmission mode of the present invention. 2b is a schematic diagram of frequency band allocation of cooperatively transmitting subframes in the cooperative transmission mode of the present invention.

FIG. 3a is a timing diagram of an application example 1 in the cooperative transmission mode of the present invention.

FIG. 3b is a timing diagram of an application example 2 in the cooperative transmission mode of the present invention.

4 is a flow chart of an eNB in a cooperative transmission mode according to the present invention.

Figure 5 is a flow chart of the Relay in the cooperative transmission mode of the present invention.

6 is a schematic diagram of frequency band allocation of a subframe in a resource reuse mode according to the present invention.

FIG. 7a is a sequence diagram of an application example 3 in the resource reuse mode of the present invention.

Figure 7b is a timing diagram of an application example 4 in the resource reuse mode of the present invention.

Figure 8 is a flow chart of an eNB in the resource reuse mode of the present invention.

FIG. 9 is a schematic diagram of frequency band allocation of a subframe in the hybrid retransmission mode of the present invention.

Figure 10 is a flow chart of the eNB in the hybrid retransmission mode of the present invention.

Preferred embodiment of the invention The invention mainly uses the second type of relay node to realize the coordinated transmission of the downlink data. The method uses the eNB and the Typell relay node as the two transmission points of the downlink data, and transparently transmits the downlink data to the user equipment. The eNB is a control node, and the control itself and the Typell relay node send downlink data to the user equipment. The Typell relay node acts as a coordinated node, and sends downlink data to the user equipment under the control of the eNB. The user equipment receives the downlink under the control of the eNB. Data, specifically, as shown in FIG. 1, the method includes the following steps:

Step 101: The evolved node (eNB) sends the first control information and the first downlink data to the relay node (RN) in the first subframe.

In order to implement coordinated transmission of downlink data, the eNB scheduler needs to perform resource scheduling in advance. The resources mentioned herein include time-frequency resources and modulation and coding scheme (MCS) resources, and the resource scheduling information is included in the above. The first control information.

Step 102: The RN receives the first control information and the first downlink data sent by the eNB, and sends a response message to the eNB in a second subframe. If the receiving succeeds, sending an acknowledgement (ACK), if If the reception fails, a negative acknowledgement (NACK) is sent;

Step 103: The eNB sends the first control information to the Relay UE in a third subframe. If the RN receives the success in step 102, the RN is in the third sub-control according to the first control information. The frame sends the first downlink data to the Relay UE.

After the step 103, if the response information sent by the RN in step 102 is ACK, the eNB sends the second control information to the RN in the fourth subframe for adaptive retransmission, otherwise the eNB is in the fourth sub The frame transmits second control information and second downlink data to the RN. The RN processes the data according to the second control information received by the fourth subframe, where the data refers to the first downlink data received in the first subframe or the second downlink data received in the fourth subframe.

Specifically, from the flow of the Un port, the hybrid automatic repeat request (HARQ) retransmission timing is satisfied, and the probability that each downlink transmission is the first transmission is high, and the probability that the contents of the two first transmissions are the same is not high. Therefore, it may be considered to select an efficient transmission method that does not require a combined transmission, that is, it is not limited to be the same retransmission, that is, the first control information is identical to the second control information, partially identical or different, and the first A downlink data is the same as or partially identical to the second downlink data.

After the step 103, the Relay UE sends to the eNB in the fifth subframe for step 102. The response message, if the reception is successful, sends a positive response, otherwise it sends a negative response.

The first sub-frame, the second sub-frame, the third sub-frame, the fourth sub-frame and the fifth sub-frame of the present invention merely indicate the timing sequence of each sub-frame, and do not limit the first sub-frame to the fifth sub-frame. The continuity of the frame.

In step 103, the eNB and the RN respectively send the first control information and the first downlink data to the Relay UE on the same frequency resource, and if the RNs in the same eNB are close to each other, in order to avoid interference, belong to different RNs. The relay UE uses different frequency resources, and in order to enhance the signal strength of the Relay UE, the eNB simultaneously transmits the first downlink data to the Relay UE in the third subframe.

If the RNs in the same eNB are far away, the relay UEs belonging to different RNs can use the same frequency resource to implement frequency resource multiplexing.

Generally, the RN receives the decoding processing time of 4 ms. In order to satisfy the delay of the relay node processing the downlink data and the control information 4 ms (ie, 4 subframes), the subframe distance of the third subframe and the first subframe should be greater than or equal to 4 subframes, further considering that the processing of the Relay includes receiving and decoding the data of the eNB, and then processing the decoded data information according to the decoded control information, so the subframe distance of the third subframe and the first subframe is prioritized. Select to be greater than 4 subframes.

The sub-frame corresponding to the first sub-frame is the n-th sub-frame, the sub-frame corresponding to the third sub-frame is the m-th sub-frame, and the sub-frame corresponding to the second sub-frame is the n+4th sub-frame, the fourth sub-frame The subframe corresponding to the frame is the n+8th subframe, and the subframe corresponding to the fifth subframe is the m+4th subframe.

The subframe in which the eNB forwards the backhauling data for a certain UE in advance to the RN will have an interval of 8 subframes.

If the eNB sends control information and downlink data for the UE to the relay node on the nth subframe, when the relay node does not successfully receive the control information and the downlink data, the relay node returns NACK in the n+4th subframe; After receiving the NACK, the control information and the downlink data for the UE will be retransmitted in the n+8th subframe; if the relay node successfully receives the control information and the downlink data, the relay node will return an ACK in the n+4th subframe. In order to use adaptive retransmission, the eNB will retransmit the control information for the UE only in the n+8th subframe, and the relay node will process the data after receiving the control information to generate the target transmitted in the specified subframe. data. These data may be sent by the eNB for the first time or may be sent by retransmission.

From the timing of the Uu port and the Un port, n and m satisfy a certain relationship. That is, n+8>m>n+4. and also That is to say, the downlink subframe of the scheduled Uu interface should be in the feedback subframe n+4 of the backhauling subframe (excluding the subframe n+4) and the next backhualing subframe n+8 (excluding the subframe m+8). between.

It can be seen that the backhauling subframe between the eNB and the RN appears every 4 subframes. If it is numbered 1, 2, 3, 4, etc., then the downlink access scheduled by the backhauling subframe 1 is accessed. The subframe will be between the number 2 backhauling subframe and the number 3 backhauling subframe.

The method of the present invention will be described in detail below with reference to the accompanying drawings:

Embodiment 1: Transmission mode of cooperative transmission.

The characteristics of the scenario that can be applied to this method are as follows: the relay distance is relatively close, and the frequency division method is used to avoid interference, and the eNB and the RN can perform the coordinated manner.

(1) Band allocation for cooperative transmission

In the backhauling subframe, the eNB allocates the bandwidth to the Relay and Relay UE and Macro UE as shown in Figure 2a: There are two Relays in the eNB cell: Relayl and Relay2, Relay1 in Relayl, and Relay2UE in Relay2. The eNB sends downlink data and control information to Relayl and Relay2 in advance. In the transmission subframe n (2 in the figure), the downlink frequency band resource of the eNB-Relayl is F1, the downlink frequency band resource of the eNB-Relay2 is F2, and the downlink frequency band resource of the eNB-Macro UE is F3.

In the access subframe, the bandwidth allocation of the eNB to the Relay and Relay UE, MacroUE is as shown in FIG. 2b, and the eNB provides coordinated transmission for the Relayl UE and the Relay2 UE. In the subframe m (subframe 7 in the figure), the Relay and the eNB transmit downlink data for the Relay UE (in the example, Relayl and Relay2) on the same frequency resource, where Fl, F2, and F3 are different from each other.

(2) Process of coordinated transmission

Application example 1

The timing diagram of application example 1 is shown in Figure 3a. The sub-frame in gray is the backhauling sub-frame. The specific performance is as follows:

Subframe 2, the eNB sends control information and downlink data to the Relay;

In subframe 6, the relay sends a response message to the eNB, and the response message is an acknowledgement (ACK); in subframe 7, the eNB and the Relay send control information and downlink data to the UE; In the next frame subframe 0, the eNB sends control information to the Relay;

The next frame subframe 1 , the UE sends a response message to the eNB and the relay, and the response message is a negative acknowledgement (NACK);

In the next frame subframe 4, the Relay sends a response message to the eNB, and the response message is an acknowledgement (ACK).

The next frame subframe 5, the eNB and the relay send control information and downlink data to the UE;

The next frame subframe 8, the eNB sends control information to the relay;

The next frame of subframe 9, the UE sends a response message to the eNB and the relay, and the response message is ACK. The Relay in this embodiment is an RN.

Application example two

The timing diagram of the application example 2 is shown in FIG. 3b, which is different from that of FIG. 3a in that: subframe 6, the relay sends a response message to the eNB, and the response message is NACK;

Subframe 7, only the eNB sends control information and downlink data to the UE;

In the next frame subframe 0, the eNB sends control information and downlink data to the relay;

The Relay in this embodiment is an RN.

The eNB flowchart and the RN flowchart corresponding to Figures 3a and 3b are shown in Figures 4 and 5.

The scheduling process of the eNB shown in Figure 4 is as follows:

Step 100: The eNB sends control information and downlink data to the relay in the nth subframe.

Step 110: The eNB receives the response information of the relay in the n+4th subframe, and the response information is a negative response. After performing step 120, step 117 is performed. Otherwise, step 120 is performed, and step 122 is performed. Step 120: The eNB passes the mth subframe. The PDCCH (Physical Downlink Control Channel) transmits control information to the UE through a PDSCH (Physical Downlink Shared Channel).

In the process of receiving data from the UE, the UE first receives PDCCH signaling, and the PDCCH is equivalent to an address, indicating the location of the PDSCH data in the time-frequency resource, and then the UE receives the PDSCH.

Step 121: The eNB sends control information and downlink data to the relay in the n+8th subframe, and then Perform step 130;

Step 122: The eNB sends control information to the relay in the n+8th subframe, and proceeds to step 130. Step 130: The eNB receives the response information of the UE in the m+4th subframe. If the response information is ACK, the process ends. Otherwise, modify n=n+8, m=m+8, and go to step 110.

The Relay in this embodiment is an RN.

The scheduling process of the RN shown in Figure 5 is as follows:

Step 200: The RN receives backhauling data in the nth subframe, including control information and downlink data. If the receiving is successful, step 212 is performed, otherwise step 211 is performed;

Step 211: The receiving failure, the RN sends a NACK to the eNB in the n+4th subframe, and proceeds to step 231.

Step 212: The receiving succeeds, the RN sends an ACK to the eNB in the n+4th subframe, and proceeds to step 220;

Step 220: The RN sends downlink data to the UE in the mth subframe according to the control information, and performs step 232;

Step 231: The RN receives the control information and the downlink data in the subframe n+8, and proceeds to step 240. Step 232: The RN receives the control information in the subframe n+8;

Step 240: The RN receives the response information of the UE in the subframe m+4. If the response information is ACK, the process ends. Otherwise, the modification n=n+8, m=m+8, and the process proceeds to step 211 or 212.

Embodiment 2 Transmission method of resource reuse.

The characteristics of the scene that can be applied in this way are: Relay is far away, located in different

The resources allocated by the UE in the relay can overlap but do not interfere with each other.

(1) Band allocation for resource reuse

As shown in FIG. 6, the eNB provides coordinated transmission for the Relay 1 UE and the Relay 2 UE. In the subframe m (subframe 7 in the figure), where Fl, and F2 can be reused resources.

(2) Resource reuse process

The timing diagram of Application Example 3 is shown in Figure 7a, and the timing diagram of Application Example 4 is shown in Figure 7b. 7a differs from FIG. 3a in that: Subframe 7, the eNB transmits control information to the UE only through the PDCCH.

The eNB flowchart and the RN flowchart corresponding to Figures 7a and 7b are shown in Figures 8 and 5, respectively. The scheduling flowchart of the eNB shown in FIG. 8 is different from the flowchart shown in FIG. 4 in that, in step 120', the eNB transmits control information to the UE only through the PDCCH in the mth subframe.

Embodiment 3: Mixed retransmission scenario.

This method can be mainly applied to the case where the allocated resources of the UE located in different Relays may interfere, and sometimes do not interfere, especially when the location of the related Relay and UE is dynamic.

(1) Band allocation for hybrid retransmission

As shown in FIG. 9, the eNB provides resource multiplexed transmission for Relay UE1 and cooperative transmission for Relay UE2. In subframe m (subframe 7 in the figure), where Fl', F2', and F3' are different resources. F1' can be used by other suitable relay UEs that do not interfere.

(2) Mixed retransmission process

The process of hybrid retransmission is shown in Figure 10 and Figure 5.

The scheduling flowchart of the eNB shown in FIG. 10 is different from the flowchart shown in FIG. 4 in that: in step 120, the determination of the transmission mode is added. If it is the coordinated transmission mode, the eNB transmits the control through the PDCCH in the mth subframe. The information is sent to the UE by using the PDSCH. If the resource is reused, the eNB sends the control information to the UE only through the PDCCH in the mth subframe.

a. In the nth subframe, the eNB sends, to the relay node (RN), first control information and first downlink data for the relay terminal device (Relay UE);

In the mth subframe, the eNB sends the first control information to the Relay UE. If the receiving succeeds, the RN sends the first downlink data to the Relay UE, where n+4<m<n+ 8; d, in the (n+8)th subframe, if the RN response information in step b is an acknowledgement (ACK), The eNB sends the second control information to the RN, otherwise sends the second control information and the second downlink data to the RN;

e. In the (m+4)th subframe, the eNB receives the response information sent by the Relay UE, and if the reception succeeds, sends an acknowledgement (ACK), and the process ends; otherwise, a negative acknowledgement (NACK) is sent to modify n=n. +8, m=m+8, loop through steps b to e until the end of the process.

In step c, the eNB and the RN respectively send the first control information and the first downlink data to the relay UE on the same frequency resource, and the Relay UEs belonging to different RNs use the same or different frequency resources.

When the frequency resources of the Relay UEs belonging to different RNs are different, the eNB in the step c sends the first downlink data to the Relay UE in the mth subframe.

In order to implement the above method, the present invention further provides a downlink data transmission system, where the system includes an evolved node (eNB) and a relay node (RN), where

The eNB is configured to send the first control information and the first downlink data for the Relay UE to the RN in the first subframe, and is further configured to send the first downlink data to the Relay UE in the third subframe. ;

The eNB is further configured to: receive the response information sent by the RN, and when the response message is a positive response, send the second control information to the RN in the fourth subframe, where the response information is a negative response, The fourth subframe sends the second control information and the second downlink data to the RN.

The sending module is configured to: when determining that the receiving is correct, send an acknowledgement to the eNB in the second subframe, and send the first downlink data to the relay terminal in the third subframe according to the first control information. When it is determined that the reception fails, a negative acknowledgement is sent to the eNB in the second subframe.

The eNB and the RN respectively send the first control information and the first downlink data to the Relay UE on the same frequency resource, and the Relay UEs belonging to different RNs may be based on the distance between the RNs. Use the same or different frequency resources.

When the frequency resources used by the Relay UEs of different RNs are different, the eNB is further configured to: send the first downlink data to the Relay UE in the third subframe to enhance the signal strength of the Relay UE. .

The control information includes time-frequency resource control information and modulation and coding policy control information.

The interval between the third subframe and the first subframe is greater than or equal to 4 ms.

In the downlink data transmission method and system of the present invention, the eNB sends the control information and the downlink data to the RN in the first subframe, the RN sends the response information to the eNB in the second subframe, and the eNB sends the control to the Relay UE in the third subframe. The RN sends the downlink data to the Relay UE in the third subframe, so that the downlink data is delivered, and the throughput of the system is increased. In addition, if interference occurs between the RNs, the eNB may send downlink data to the Relay UE in addition to the downlink control information in the third subframe, which may enhance the UE signal strength; if the distance between the RNs is far away, no interference occurs. The eNB sends only the control information to the Relay UE, and the different RNs transmit the downlink data to the associated Relay UE on the same frequency resource, thereby implementing multiplexing of the frequency resources.

The present invention also discloses a relay node RN, the RN is configured to receive the first control information and the first downlink data sent by the evolved node eNB, and determine whether the first control information and the first downlink data are correctly received. And if the first control information and the first downlink data are correctly received, sending the first downlink data to the relay terminal in a third subframe according to the first control information; where, the first sub The frame precedes the second subframe, and the second subframe precedes the third subframe.

The RN in this embodiment has the same function as the RN in the system embodiment, and details are not described herein.

The RN can implement downlink data delivery and increase system throughput.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be performed by a program to instruct the associated hardware, such as a read only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware, or may be implemented in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software. Industrial applicability

The downlink data transmission method and system provided by the present invention, the eNB sends control information and downlink data to the RN in the first subframe, the RN sends the response information to the eNB in the second subframe, and the eNB sends the response message to the Relay UE in the third subframe. The control information is sent, and the RN sends the downlink data to the Relay UE in the third subframe, thereby implementing downlink data transmission and increasing the throughput of the system. In addition, if interference occurs between the RNs, the eNB may send downlink data to the Relay UE in addition to the downlink control information in the third subframe, which may enhance the UE signal strength; if the distance between the RNs is far, no interference occurs. The eNB sends only the control information to the relay UE, and the different RNs transmit the downlink data to the associated Relay UE on the same frequency resource, thereby implementing multiplexing of the frequency resources.

Claims

Claim

1. A method for transmitting downlink data, the method comprising:

The evolved Node B (eNB) transmits the first control information and the first downlink data to the relay node RN in the first subframe;

2. The method of claim 1 wherein

In the step of transmitting the response information to the eNB in the second subframe, if the response information sent by the RN is a positive response, the eNB sends the first subframe to the relay terminal UE in the third subframe. After a step of controlling information, the method further includes:

The eNB sends the second control information to the RN in the fourth subframe. If the response information sent by the RN is a negative response, the eNB sends the second control information to the RN in the fourth subframe. The second downlink data, wherein the third subframe precedes the fourth subframe in a timing relationship.

3. The method according to claim 2, wherein: the first control information is the same as or partially different from the second control information, and the first downlink data is the same as the second downlink data, partially identical or different.

4. The method according to claim 1, wherein in the step of the eNB transmitting the first control information to the relay terminal UE in the third subframe,

When the frequency resources used by the relays belonging to different RNs are different, the eNB sends the first downlink data to the relay UE while the first subframe transmits the first control information.

5. The method of claim 1, wherein: between the third subframe and the first subframe The interval is greater than or equal to 4ms.

The method according to claim 2, wherein, in the step of the RN transmitting the response information to the eNB in the second subframe, if the response information sent by the RN is a positive response, the eNB is The fourth subframe sends the second control information to the RN. If the response information sent by the RN is a negative response, the eNB sends the second control information and the second downlink data to the RN in the fourth subframe. After the step, the method further includes:

A downlink data transmission system, the system comprising an evolved Node B (eNB) and a relay node RN, wherein

8. The system according to claim 7, wherein: the eNB is further configured to: receive response information sent by the RN, where the response information is a positive response, and send the message to the RN in a fourth subframe. The second control information, when the response information is a negative response, sends the second control information and the second downlink data to the RN in the fourth subframe.

The system according to claim 7, wherein: the eNB is further configured to: when the frequency resources used by the relay UEs belonging to different RNs are different, send the first control information in the third subframe The first downlink data is sent to the relay UE.

10. The system of claim 7, wherein: the interval between the third subframe and the first subframe is greater than or equal to 4 ms.

A relay node RN, the RN is configured to receive the first control information and the first downlink data sent by the evolved Node B, and determine whether the first control information and the first downlink data are correctly received. And if the first control information and the first downlink data are correctly received, sending the first downlink data to the relay terminal in the third subframe according to the first control information.