CN101383685A - Method, system and device for downlink hybrid automatic retransmission - Google Patents

Abstract

The invention discloses a downlink hybrid automatic retransmission method, comprising: a relay station (RS) and a mobile station (MS) respectively receive downlink data subframes sent by a base station (BS) to the MS, and respectively return respective received correct Response or a response indicating reception error to the BS; if the RS receives the downlink data subframe correctly, the RS caches the downlink data subframe; if the MS returns an uplink response to the BS to indicate that it has received a correct response, the RS releases the downlink data cached by itself data subframe. The invention also discloses a downlink hybrid automatic retransmission system and an RS. After using the present invention, after the RS and the MS correctly receive the downlink data subframes sent to the MS, the RS can quickly and accurately release the data subframes cached by itself, thereby improving the capacity and performance of the RS.

Description

Method, system and device for downlink hybrid automatic retransmission

technical field

The present invention relates to communication technology, in particular to a downlink hybrid automatic retransmission method, system and device.

Background technique

In a traditional cellular network, the wireless connection between the base station (BS, Base Station) and the mobile station (MS, MobileStation) is a direct wireless connection, that is, the concept of "single hop" is adopted. However, in the planning stage of base station coverage, it is usually difficult to avoid terrain and ground objects that may cause shadow fading effects in some areas of the signal. Therefore, it is necessary to use a relay system to improve signal coverage. The relay station (RS, Relay Station) first receives the signal sent from the base station/user terminal, and then forwards the signal to the user terminal/base station. Appropriate placement of RS can improve signal coverage, and at the same time, signal regeneration can be achieved when relaying and retransmitting signals. The two-pronged approach can greatly improve the signal quality received by the user end.

At the same time, due to the time-varying and multi-path fading characteristics of the wireless mobile channel, there is a relatively high bit error rate. In order to ensure the quality of service, error control methods are generally adopted at the data link layer. Among them, the hybrid automatic repeat request (HARQ, Hybrid Automatic Repeat Request) technology is a low-level feedback retransmission mechanism, and HARQ can perform retransmission at the physical layer. The sending end adds CRC (Cyclic Redundancy Check) data to the data block to be sent. After the channel transmission, the receiving end decodes the data block and performs CRC calculation on the data block. The data block can be judged according to the calculation result was received correctly. Then, the receiving end will feed back the receiving status to the sending end at the specified time, and the sending end will determine whether to retransmit the data block according to the status information fed back by the receiving end. If the receiving end feedbacks that the reception is correct (ack), the sending end will start Send new data; if the receiving end feeds back a reception error (nack), the sending end retransmits the data block.

In existing standards, Transparent RS describes a DL RS assisted HARQ process for centralized scheduling. The purpose of this process is to use the RS to assist the retransmission between the terminal and the BS, so as to improve the reliability of system transmission. Its main idea is that when the BS directly sends data to the terminal, it notifies the RS to monitor the data of the session at the same time, the RS monitors and decodes the data, and feeds back a response to the BS, and the BS determines whether the retransmission is initiated by itself or RS is notified to initiate. DL RS assistedHARQ defines two methods, one is the encoded ack/nack method, in this method, after the BS sends a downlink data subframe to the MS, the RS determines how to feed back the receiving information to the BS according to the receiving information returned by the MS, The BS judges and processes data retransmission according to the receiving information fed back by the RS. In this manner, the RS performs processing according to the MS response, thus increasing the complexity of the RS implementation. Another method is the direct ack/nack method. The RS does not care about the response of the MS, but the BS judges and processes the data retransmission according to the respective responses of the RS and the MS, thereby reducing the complexity of the RS implementation.

Fig. 1 is a flowchart of a downlink hybrid automatic retransmission method in the prior art. As shown in Figure 1, the method includes the following steps:

Step 100: The BS allocates downlink resources and uplink resources for the RS, and instructs the RS to monitor the downlink data sub-frame (data sub-burst) sent by the BS to the MS.

In this step, the BS allocates downlink resources to the RS in the downlink map (DL-MAP, Downlink MAP), and sends the DL-MAP monitoring information element (DL-MAP MONITOR IE) to notify the RS to monitor the data sub-item of certain connections of the UE. Frame, in the DL-MAP MONITOR IE, the connection identifier (CID, Connection Identifier) is used to instruct the RS to monitor the data of which connections. At the same time, in the uplink mapping (UL-MAP, Uplink MAP) of the frame, an uplink resource response channel (UL ackchannel) is allocated to the RS, and the RS is used to feed back the receiving information of the downlink HARQ data subframe, that is, ack or nack information. In addition, the DL-MAP MONITOR IE indicates that the RS adopts the direct ack/nack method. At this time, the RS will monitor the downlink data but not the corresponding uplink ack/nack.

Step 101: The BS allocates downlink and downlink resources for the MS.

In this step, the BS allocates downlink resources to the MS in the DL-MAP in the same frame as in step 100, and at the same time allocates uplink resources to the MS in the UL-MAP UL ack channel for the MS to feed back the downlink HARQ data subframe The received information, that is, ack or nack information.

Step 102: In the downlink data subframe of the same frame, the BS directly sends data to the MS. At the same time, the RS monitors the data subframe of the connection corresponding to the CID indicated in the DL-MAP MONITOR IE.

Then the RS and the MS decode the received data separately, and enter different processing procedures according to the decoding result.

casel:

Step 103: After listening to the downlink data subframe of the connection corresponding to the indicated CID, the RS decodes the data and judges whether the reception is correct or wrong. If receiving an error, return nack to the BS in the UL ack channel allocated by the BS. At this time, the RS will not buffer the received downlink data subframe.

Step 104: The MS decodes the downlink data subframe after receiving it, and judges whether the subframe is received correctly or incorrectly. If receiving an error, return nack to the BS in the UL ack channel allocated by the BS.

Step 105: The BS determines that neither the RS nor the MS succeeds in decoding the data according to the received nack of the RS and the nack of the MS, and at this time, the BS determines to retransmit the data by itself.

Case2:

Step 106: After listening to the downlink data subframe of the indicated CID, the RS decodes the data and judges whether the reception is correct or wrong. If receiving an error, return nack to the BS in the UL ack channel allocated by the BS. At this time, the RS will not buffer the received downlink data subframe.

Step 107: The MS decodes the downlink data subframe after receiving it, and judges whether the subframe is received correctly or incorrectly. If the reception is correct, an ack is returned to the BS in the UL ack channel allocated by the BS, that is, the data subframe is successfully transmitted.

Case3:

Step 108: After listening to the downlink data subframe of the connection corresponding to the CID, the RS decodes the data and determines whether the reception is correct or wrong. If the reception is correct, the RS buffers the received downlink data subframe so that it can be used for data retransmission when needed.

Step 109: At this time, the RS returns an ack to the BS in the UL ack channel allocated by the BS.

Step 110: The MS decodes the downlink data subframe after receiving it, and judges whether the subframe is received correctly or incorrectly. If receiving an error, return nack to the BS in the UL ack channel allocated by the BS.

Step 111: The BS determines that the RS is received correctly and the MS receives an error according to the received ack of the RS and the nack of the MS. At this time, the BS determines that the data is retransmitted by the RS.

Case4:

Step 112: After listening to the downlink data subframe of the connection corresponding to the CID, the RS decodes the data and determines whether the reception is correct or wrong. If the reception is correct, the RS buffers the received downlink data subframe so that it can be used for data retransmission when needed.

Step 113: The RS returns an ack to the BS in the UL ack channel allocated by the BS.

Step 114: The MS decodes the downlink data subframe after receiving it, and judges whether the subframe is received correctly or incorrectly. If the reception is correct, an ack is returned to the BS in the UL ack channel allocated by the BS, that is, the frame is successfully transmitted.

It can be seen that in the existing downlink hybrid automatic retransmission method, when the RS receives the data correctly and caches the data, no matter whether the MS receives it correctly or receives it incorrectly, there is no mechanism to notify the RS, that is, for both cases 3 and 4, it will As a result, the data subframes buffered in the RS cannot be released, and the data buffered in the RS cannot be released in time, thus directly affecting the capacity and performance of the RS.

Contents of the invention

The embodiment of the present invention provides a downlink hybrid automatic retransmission method, so that the RS can quickly and accurately release the data in the cache, and improve the capacity and performance of the RS.

The embodiment of the present invention also provides a downlink hybrid automatic retransmission system, so that the RS can quickly and accurately release the data in the cache, and improve the capacity and performance of the RS.

The embodiment of the present invention also provides an RS, so that the RS can quickly and accurately release the data in the cache, and improve the capacity and performance of the RS.

In order to achieve the above object, the technical solution of the embodiment of the present invention is achieved in this way:

A method for downlink hybrid automatic retransmission, comprising:

The relay station RS and the mobile station MS respectively receive the downlink data subframes sent by the base station BS to the MS, and return respective responses indicating that the reception is correct or that the reception is wrong to the BS;

If the RS receives the downlink data subframe correctly, the RS caches the downlink data subframe; if the uplink response returned by the MS to the BS is a response indicating that it is received correctly, the RS releases the downlink data subframe cached by itself.

A downlink hybrid automatic retransmission system, including a base station BS and a relay station RS,

The BS is configured to send downlink data subframes to the MS; receive uplink responses returned by the MS and the RS respectively;

The RS is configured to receive the downlink data subframe sent by the BS to the MS, and return an uplink response to the BS; if the downlink data subframe is received correctly, buffer the downlink data subframe; if the MS returns the uplink data subframe to the BS The response is to indicate that a correct response is received, and the downlink data subframe buffered by itself is released.

A relay station RS, including a receiving module, a verification module, a buffer module and an uplink response judging module,

The receiving module is used to receive the downlink data subframe sent by the base station BS to the mobile station MS;

The checking module is configured to cache the downlink data subframe by the buffering module when the receiving module correctly receives the downlink data subframe;

The uplink response judging module is used for judging that the uplink response returned by the MS to the BS is a correct response, and the buffering module releases the buffered downlink data subframe.

Compared with the prior art, in the technical solution provided by the embodiment of the present invention, the RS correctly receives the downlink data subframe sent by the BS to the MS, and when the MS also successfully receives the downlink data subframe sent by the BS, the RS can obtain the The downlink data subframe receives a correct response, so that the downlink data subframe cached by itself can be deleted, avoiding the problem that the buffer resources in the RS cannot be released in time, and improving the capacity and performance of the RS.

Description of drawings

FIG. 1 is a flowchart of a method for downlink hybrid automatic retransmission in the prior art;

FIG. 2 is a flowchart of a method for downlink hybrid automatic retransmission in an embodiment of the present invention;

FIG. 3 is a flowchart of a downlink hybrid automatic retransmission method in Embodiment 1 of the present invention;

FIG. 4 is a flowchart of a downlink hybrid automatic retransmission method in Embodiment 2 of the present invention;

FIG. 5 is a system structure diagram of downlink hybrid automatic retransmission in an embodiment of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

FIG. 2 is a flowchart of a downlink hybrid automatic retransmission method in an embodiment of the present invention. As shown in Figure 2, the method includes the following steps: In step 200, the RS and the MS respectively receive the downlink data subframes sent by the BS to the MS, and return respective responses indicating correct reception or responses indicating incorrect reception to the BS; In step 201, if the RS receives the downlink data subframe correctly, it buffers the downlink data subframe; and executes step 202: if the uplink response returned by the MS to the BS is a response indicating that the reception is correct, the RS releases the downlink data subframe cached by itself .

The method for downlink hybrid automatic retransmission of the present invention will be further described in detail below with two embodiments. In the embodiments described below, the response indicating correct reception is ack, and the response indicating incorrect reception is nack. Those skilled in the art can understand that the response indicating that the response is received correctly and the response indicating that the response is received incorrectly may be other responses than ack and nack.

Embodiment one:

In the method for realizing downlink hybrid automatic retransmission in this embodiment, the RS monitors the uplink response returned by the MS to the BS.

FIG. 3 is a flowchart of a downlink hybrid automatic retransmission method in Embodiment 1 of the present invention. As shown in Figure 3, the method includes the following steps:

Step 300: The BS allocates uplink and downlink resources for the RS, and instructs the RS to monitor the data subframe sent by the BS to the MS; the RS monitors the uplink response returned by the MS to the BS by default.

In this step, the BS allocates downlink resources to the RS in the DL-MAP, and sends the DL-MAPMONITOR IE to notify the RS to monitor the data subframes of certain connections of the UE, and uses the CID in the DL-MAPMONITOR IE to indicate which connections the RS monitors The data. At the same time, the uplink resource UL ack channel is allocated to the RS in the UL-MAP of the frame, and the RS is used to feed back the receiving information of the downlink HARQ data subframe, that is, ack or nack. In addition, the DL-MAP MONITOR IE indicates that the RS adopts the direct ack/nack mode. At this time, the RS will monitor the downlink data subframe, and at the same time, monitor the MS's uplink response ack/nack by default; or the BS instructs the RS to monitor the downlink data subframe and the uplink response of the MS, the RS monitors the downlink data subframe and the uplink response of the MS.

Step 301: BS allocates uplink resource and downlink resource to MS.

In this step, the BS allocates downlink resources to the MS in the DL-MAP of the same frame as in step 300, and at the same time allocates uplink resources UL ack channel to the MS in the UL-MAP, so that the MS can feed back the reception of the downlink HARQ data subframe Information, that is, ack or nack information.

Step 302: In the downlink data subframe of the same frame, the BS directly sends data to the MS. At the same time, the RS monitors the data subframe of the connection corresponding to the CID indicated in the DL-MAP MONITOR IE.

Then the RS and the MS decode the received data separately, and enter different processing procedures according to the decoding result.

casel:

Step 303: After listening to the downlink data subframe of the connection corresponding to the CID, the RS decodes the data and determines whether the reception is correct or wrong. If receiving an error, return nack to the BS in the UL ack channel allocated by the BS. At this time, the RS does not buffer the received downlink data subframe.

Step 304: The MS decodes the downlink data subframe after receiving it, and judges whether the subframe is received correctly or incorrectly. If receiving an error, return nack to the BS in the UL ack channel allocated by the BS.

Step 305: The BS determines that neither the RS nor the MS decodes the data successfully according to the received nack of the RS and the nack of the MS, and at this time, the BS determines to retransmit the data by itself.

Case2:

Step 306: After listening to the downlink data subframe of the connection corresponding to the CID, the RS decodes the data and determines whether the reception is correct or wrong. If receiving an error, return nack to the BS in the UL ack channel allocated by the BS. At this time, the RS does not buffer the received downlink data subframe.

Step 307: The MS decodes the downlink data subframe after receiving it, and judges whether the subframe is received correctly or incorrectly. If the reception is correct, an ack is returned to the BS in the UL ack channel allocated by the BS, that is, the frame is successfully transmitted.

Case3:

Step 308: After listening to the downlink data subframe of the connection corresponding to the CID, the RS decodes the data and determines whether the reception is correct or wrong. If the reception is correct, the RS buffers the received downlink data subframe so that it can be used for data retransmission when needed.

Step 309: At this time, the RS returns an ack to the BS in the UL ack channel allocated by the BS.

Step 310: The MS decodes the downlink data subframe after receiving it, and judges whether the subframe is received correctly or incorrectly. If receiving an error, return nack to the BS in the UL ack channel allocated by the BS.

Step 311: The BS determines that the RS is received correctly and the MS is received incorrectly according to the ack received from the RS and the nack received from the MS. At this time, the BS retransmits data through the RS.

Step 312: The RS detects that the MS returns an ack, and then releases the buffered data subframe.

Case4:

Step 313: After listening to the downlink data subframe of the connection corresponding to the CID, the RS decodes the data and determines whether the reception is correct or wrong. If the reception is correct, the RS buffers the received downlink data subframe so that it can be used for data retransmission when needed.

Step 314: The RS returns an ack to the BS in the UL ack channel allocated by the BS.

Step 315: The MS decodes the downlink data subframe after receiving it, and judges whether the subframe is received correctly or incorrectly. If the reception is correct, an ack is returned to the BS in the UL ack channel allocated by the BS, that is, the frame is successfully transmitted.

Step 316: After listening to the response ack returned by the MS to the BS, the RS releases the downlink data subframes buffered by itself.

Embodiment two:

In the method for realizing downlink hybrid automatic retransmission in this embodiment, the BS notifies the RS of the ack response information from the MS.

FIG. 4 is a flowchart of a downlink hybrid automatic retransmission method in Embodiment 2 of the present invention. As shown in Figure 3, the method includes the following steps:

Step 400: The BS allocates uplink and downlink resources for the RS, and instructs the RS to monitor the data subframe sent by the BS to the MS.

Steps 401 to 410 are the same as those described in Steps 301 to 310 in Embodiment 1, and will not be repeated here.

Step 411: The BS determines that the RS is received correctly and the MS receives incorrectly according to the received ack of the RS and the nack of the MS, and the BS determines that the data is retransmitted by the RS.

Steps 412 to 414 are the same as steps 313 to 315 and will not be described in detail here.

Steps 415 to 416: After receiving the ack returned by the MS, the BS notifies the RS, and the RS releases the downlink data subframes buffered by itself after receiving the ack.

FIG. 5 is a system structure diagram of downlink hybrid automatic retransmission in an embodiment of the present invention. As shown in Figure 5, the system includes BS and RS.

Wherein, the BS is used to send the downlink data subframe to the MS; when receiving the uplink response returned by the MS, and judging that the uplink response is nack, it is determined that the RS performs the data retransmission of the downlink data subframe;

RS is used to monitor the downlink data subframe sent by the BS to the MS. When the downlink data subframe is received correctly, the downlink data subframe is cached; when the uplink response returned by the MS to the BS is ack, the downlink data cached by itself is released subframe.

Specifically, the RS includes a receiving module, a checking module, a buffering module and an uplink response judging module.

The receiving module is used to receive the downlink data subframe sent by the base station BS to the mobile station MS; the verification module is used to judge that when the receiving module correctly receives the downlink data subframe, the buffer module buffers the downlink data subframe; the uplink response judgment module is used for judging that the uplink response returned by the MS to the BS indicates that the response is received correctly, and the buffering module releases the buffered downlink data subframe.

The RS in the embodiment of the present invention may further include a monitoring module, which is used to monitor the uplink response returned by the MS to the BS; correspondingly, the uplink response judging module judges that the uplink response indicates reception according to the uplink response monitored by the monitoring module correct response.

The receiving module of the RS in the embodiment of the present invention can receive the notification sent by the BS to the RS when receiving the correct response returned by the MS to the BS; correspondingly, the uplink response judging module judges that the uplink response is an indication Receive the correct response.

It can be seen from the above that, in the technical solution provided by the embodiment of the present invention, after the RS correctly receives and buffers the downlink data subframe sent by the BS, if the MS also correctly receives the downlink data subframe, the RS can obtain the MS Receive a correct response to the downlink data subframe, or after the MS fails to receive the downlink data subframe sent by the BS, but the RS correctly receives the downlink data subframe, the RS retransmits the data, and the MS receives the retransmission result. The downlink data subframe responds correctly, so that the downlink data subframe cached by itself can be deleted, so as to quickly and accurately release the data cached in the RS, and greatly improve the capacity and performance of the RS.

The serial numbers of the above embodiments of the present invention are for description only, and do not represent the advantages and disadvantages of the embodiments. The word "step" described in the above embodiments of the present invention does not represent the order in which the methods are executed in the embodiments.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (14)

1, a kind of method of down mixing self-retransmission is characterized in that, this method comprises:

Relay station RS and mobile station MS receive base station BS respectively to the down data subframes that MS sends, and BS is given in the response of returning respectively separately that expression receives correctly or the expression reception is wrong;

If correct described down data subframes, the described down data subframes of RS buffer memory of receiving of RS; If MS receives correct response to the up response that BS returns for expression, the down data subframes of RS release self buffer memory.

2, the method for claim 1 is characterized in that, this method further comprises:

If the up response that MS returns receives wrong response for expression, BS determines to carry out the re-transmission of described down data subframes by RS.

3, method as claimed in claim 2 is characterized in that, the re-transmission that described RS carries out described down data subframes comprises:

RS sends described down data subframes to MS;

If MS receives correct response to the up response that BS returns for expression, the down data subframes of RS release self buffer memory.

As each described method in the claim 1 to 3, it is characterized in that 4, before the down data subframes of RS release self buffer memory, this method further comprises: the expression that BS returns MS receives correct response and is notified to RS;

If RS determines up response that MS returns to BS for expression receives correct response according to the notice of BS, discharge the down data subframes of self buffer memory.

As each described method in the claim 1 to 3, it is characterized in that 5, before the down data subframes of described RS release self buffer memory, this method further comprises: RS monitors the up response that MS returns to BS;

If RS listens to described up response for expression receives correct response, discharge the down data subframes of self buffer memory.

6, method as claimed in claim 5 is characterized in that, described BS indication RS monitors the up response that MS returns to BS.

7, the method for claim 1 is characterized in that, it is ack that described expression receives correct response; It is nack that described expression receives wrong response.

8, a kind of system of down mixing self-retransmission is characterized in that, this system comprises base station BS and relay station RS,

Described BS is used for sending down data subframes to MS; Receive the up response that MS and RS return separately;

Described RS is used to receive described BS to the down data subframes that MS sends, and returns up response to BS; If correct described down data subframes, the described down data subframes of buffer memory of receiving; If the up response that MS returns to BS, discharges the down data subframes of self buffer memory for expression receives correct response.

9, system as claimed in claim 8, it is characterized in that, described BS determines to receive the up response that RS returns and receives correct response for expression, and the up response that MS returns receives wrong response for expression, determines to carry out the re-transmission of described down data subframes by RS.

10, system as claimed in claim 8 or 9 is characterized in that, the expression that described BS returns MS receives correct response and is notified to RS;

Described RS determines up response that MS returns to BS for expression receives correct response according to the notice of BS, discharges the down data subframes of self buffer memory.

11, system as claimed in claim 8 or 9 is characterized in that, described RS monitors the up response that MS returns to BS, receives correct response if listen to expression, discharges the down data subframes of self buffer memory.

12, a kind of relay station RS is characterized in that, this RS comprises receiver module, verification module, cache module and up response judge module,

Described receiver module is used to receive the down data subframes that base station BS sends to mobile station MS;

Described verification module is used to judge when described receiver module correctly receives described down data subframes, by the described down data subframes of cache module buffer memory;

Described up response judge module is used to judge when up response that MS returns to BS receives correct response for expression, is discharged the down data subframes of buffer memory by described cache module.

13, RS as claimed in claim 12 is characterized in that, described RS further comprises the monitoring module, is used to monitor the up response that MS returns to BS;

Described up response judge module judges that according to the up response that described monitoring module listens to described up response receives correct response for expression.

14, method as claimed in claim 12 is characterized in that, described receiver module receives BS and receiving the notice that expression that MS returns to BS sends to RS when receiving correct response;

Described up response judge module judges that according to the notice that described BS sends described up response receives correct response for expression.

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