WO2010124517A1

WO2010124517A1 - Method and system for realizing hybrid automatic repeat request (harq)

Info

Publication number: WO2010124517A1
Application number: PCT/CN2009/076299
Authority: WO
Inventors: 朱登魁; 梁婷; 李子荣; 刘颖
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-04-28
Filing date: 2009-12-30
Publication date: 2010-11-04
Also published as: CN101877630B; CN101877630A

Abstract

A method and system for realizing Hybrid Automatic Repeat Request (HARQ) are provided by the present invention. Wherein the method includes that: a transmitting end retransmits the HARQ data packet failed to be transmitted according to the preset retransmission policy, for receiving by a receiving end. By applying the method and system of the present invention, the independent HARQ data packet failed to be transmitted is retransmitted according to the preset retransmission policy not only retransmitted continually in the former transmission manner, so the success rate of retransmission is improved; meanwhile, the space diversity effect of multiple independent data flow channels are used, thereby the diversity of the system is advanced. Furthermore, because the retransmission policy is preset, the signaling costs occupied by performing a retransmission manner notification in the system can be avoided.

Description

Method and system for implementing hybrid automatic retransmission

The present invention relates to the field of communications, and in particular, to a method and system for implementing Hybrid Automatic Repeat Request (HARQ). Background technique

At present, with the continuous development of wireless communication technologies, many new technologies have emerged in the field of wireless communication, such as OFDM (Orthogonal Frequency Division Multiplexing) technology and multiple input multiple output (MIMO, Multiple-Input). Multiple-Output technology, which can effectively improve the performance of communication systems to meet the growing demand for data services.

Among them, MIMO technology is an important technological breakthrough in multi-antenna technology in the field of wireless communications. MIMO technology can increase the system capacity without increasing the spectrum resources, so that the capacity can be expanded without increasing the carrier frequency and the base station; and, by using MIMO technology, various diversity gains can be obtained to improve the quality of the received signal and reduce The bit error rate, thereby improving the stability of the communication system. Therefore, MIMO technology has a significant role in improving the performance of communication systems.

In addition, the use of HARQ technology is also widely used in wireless communication systems, which combines automatic retransmission techniques and forward error correction coding techniques for error detection and correction. Based on the HARQ technology, there are mainly two HARQ modes: (1) The receiving end saves the packet that cannot be correctly received, and notifies the transmitting end, and then the receiving end detects by combining the saved data and the same data sent by the transmitting end again. (2) The receiving end saves the packet that cannot be correctly received, and notifies the transmitting end, after which the receiving end detects by combining the saved data and the different versions of redundant data sent by the transmitting end again.

In a MIMO system using multiple codewords, each layer uses a separate modulation and coding scheme. It is a separate HARQ packet that is then sent out over the data link of the multi-antenna system. Correspondingly, at the receiving end, multiple H ARQ data packets corresponding to multiple layers need to be separately detected and notified to the transmitting end.

FIG. 1 is a schematic diagram of data transmission between a transmitting end and a receiving end in a communication system in which a synchronous HARQ mechanism and a multi-antenna technology are enabled in the prior art.

As shown in FIG. 1, on the transmitting side, data sources 1 to L respectively use respective encoding and modulation, namely: encoding and modulation 1 to L in FIG. 1, modulating and encoding the data, and encoding the plurality of modulations. The data is MIMO encoded and precoded and transmitted to the receiving end via the plurality of transmitting antennas Tx1 to TxM. On the receiving end side, data is received through the plurality of receiving antennas Rx1 to RxN, and then the received data is subjected to MIMO detection, and finally The data of the plurality of data sources 1 to L are respectively subjected to demodulation, decoding, and Cyclic Redundancy Check (CRC) verification, and the data of the data source is restored. After demodulating, decoding, and CRCing the data of each data source, it is determined whether the data of the data source is successfully received. For the successfully received data, a correct response message (ACK) may be fed back. For erroneously received data, an error response message (NACK) needs to be returned.

Moreover, for the data packet that fails to be transmitted, the sender will retransmit, and when the retransmission is performed, the correspondence between the data packet and the layer is not changed; for the data packet that is successfully transmitted, no retransmission is performed. And the sender will transmit the new data packet using the layer that transmits the data packet. Therefore, the failed data packet will continue to be transmitted on the original transmission failure layer. If the channel quality of the layer is not ideal, the data retransmitted by the layer will be difficult to successfully transmit to the receiving end, which will cause data delay. Even lost.

In the prior art, due to the fixed correspondence between the retransmission data packet and the layer, the transmission success rate of the retransmission data is low, thereby increasing the transmission delay or even the loss of data. Currently, no effective solution has been proposed. Summary of the invention

The present invention has been made in view of the problem in the prior art that the transmission delay or even the loss of data is increased due to the fixed correspondence between the retransmission packet and the layer. To this end, the main object of the present invention is to provide a hybrid automatic weight. The implementation of the pass.

According to an aspect of the present invention, a method for implementing hybrid automatic retransmission HARQ is provided for implementing HARQ in a case where a system performs multi-codeword stream transmission using multiple layers.

The method for implementing the HARQ according to the present invention includes: the transmitting end retransmits the HARQ data packet that failed to be transmitted according to a predetermined retransmission policy, and is received by the receiving end.

The foregoing retransmission policy may include at least one of the following:

Changing the transmission mode of the HARQ data packet that failed to be transmitted, and performing retransmission according to the changed transmission mode;

The layer for retransmission is selected according to the channel qualities of the multiple layers, and the selected layer is used for retransmission.

Specifically, the transmission manner of changing the HARQ data packet that fails to transmit may include at least one of the following:

Changing the number of independent HARQ packets transmitted during retransmission;

Changing the number of layers occupied by HARQ packets transmitted during retransmission;

Change the correspondence between the retransmission packet and the layer of the HARQ packet that failed to be transmitted. Optionally, the channel quality of the foregoing multiple layers may be obtained by channel measurement performed in advance, or obtained by channel information fed back by the receiving end.

Optionally, the foregoing predetermined retransmission policy may be preset by the system and notified to the sending end and the receiving end;

Alternatively, the foregoing predetermined retransmission policy is determined in advance by the sender and the receiver. Alternatively, the predetermined retransmission policy is determined by the sender and the receiver in advance according to a communication protocol therebetween. In the method, for each HARQ packet that fails to be transmitted, each of the retransmitted data packets is composed of some or all of the data in the corresponding code stream of the HARQ packet, and the HARQ data packet is represented by the same code stream. Multiple HARQ packets correspond to the same independent HARQ packet.

Optionally, the sending end is specifically a base station, and the receiving end is specifically a relay station or a terminal;

Or, the sending end is specifically a terminal, and the receiving end is specifically a base station or a relay station;

Alternatively, the transmitting end is a relay station, and the receiving end is a base station or a terminal.

Preferably, for the transmitted HARQ data packet, there is a predetermined time interval between the transmission of the HARQ data packet and its retransmitted data packet, and the HARQ data packet and its retransmitted data packet occupy the frame structure The resources are in the same location.

According to another aspect of the present invention, an implementation system of HARQ is provided.

The implementation system of the HARQ according to the present invention includes: a transmitting end and a receiving end; wherein, the sending end is configured to retransmit the HARQ data packet that fails to be transmitted according to a predetermined retransmission policy;

The receiving end is configured to receive the HARQ data packet from the sending end, and receive the retransmitted data packet according to the retransmission policy.

The transmitting end is further configured to transmit the HARQ data packet through some or all of the multiple layers. The upper retransmission strategy includes at least one of the following:

With the above technical solution of the present invention, the independent HARQ data packet that fails to be transmitted is retransmitted according to a predetermined retransmission policy, instead of continuing the retransmission only in the original transmission mode, thereby improving the success rate of retransmission and being able to utilize Spatial diversity effects of multiple independent data stream channels, In addition, the diversity of the system is improved; in addition, since the retransmission policy is predetermined, the signaling overhead occupied by the retransmission mode notification in the system can be avoided. DRAWINGS

1 is a schematic diagram of a communication link of a wireless communication system of a synchronous HARQ in the prior art; FIG. 2 is a flowchart of a method for implementing HARQ according to an embodiment of the method of the present invention; FIG. 1 is a schematic diagram of packet transmission and retransmission; Schematic diagram of Example 2 of retransmission; Schematic diagram of Example 3 of packet transmission and retransmission; Schematic diagram of Example 4 of packet transmission and retransmission; Schematic diagram of Example 5 of packet transmission and retransmission; Example 6 of packet transmission and retransmission Schematic diagram

FIG. 9 is a block diagram of an implementation system of HARQ according to an embodiment of the system of the present invention. The present invention proposes: For the transmission failure, the transmission success rate of the retransmission data is low due to the fixed correspondence between the retransmission data packet and the layer, and the transmission delay or even the data is lost. The independent HARQ data packet is retransmitted according to a predetermined retransmission policy, instead of continuing to retransmit only in the original transmission mode, thereby improving the success rate of retransmission, and since the retransmission policy is predetermined, it can be avoided. Re-transmitted mode notification in the system Signaling overhead. The invention will be described in detail below with reference to the accompanying drawings.

Method embodiment:

2 is a flowchart of a method for implementing HARQ according to an embodiment of the present invention. When the system uses multiple layers for multi-codeword stream transmission, that is, a case where a synchronous HARQ mechanism and a multi-antenna technology are enabled, for example, The system shown in Figure 1 implements HARQ. It should be noted that the steps described in the following methods may be performed in a computer system such as a set of computer executable instructions, and although the logical order is illustrated in FIG. 2, in some cases, may be different The steps shown or described are performed in the order herein. Layer refers to the number of codeword streams that the system can transmit simultaneously.

As shown in FIG. 2, the method for implementing HARQ in this embodiment includes step S202 and step S204. The processing shown in Figure 2 specifically includes:

Step S202: The transmitting end retransmits the HARQ data packet that failed to be transmitted according to a predetermined retransmission policy.

The situation in this step is: In the case that the HARQ packet transmission on some or all of the multiple layers fails, at this time, it can also be understood that the independent HARQ packet transmission corresponding to the HARQ packet fails. . Preferably, at the time of retransmission, there is a predetermined time interval between the transmission of the data packet and the transmission of the retransmission packet, and the data packet is the same as the resource location occupied by the retransmission packet in the frame structure.

Step S204: The receiving end receives the data sent by the sending end.

Through the above processing, by retransmitting the data according to the retransmission policy, data retransmission using the same transmission mode can be avoided, and the problem of low retransmission success rate, large transmission delay, and even loss of data in the prior art is solved. And it is possible to omit the notification message every time the retransmission policy is changed.

Wherein, for each HARQ packet that fails to be transmitted, the retransmitted data packet is composed of some or all of the data in the code stream of the HARQ data packet, and is used to represent the HARQ data packet, that is, each of the transmitted data packets HARQ data packets correspond to one code stream, and each code stream can be constructed. The plurality of HARQ data packets represent only, or only correspond to, the independent HARQ data packet or the codeword stream of the data packet, and the multiple HARQ data packets have different versions.

The foregoing retransmission policy may include at least one of: changing a transmission mode of a HARQ packet that fails to be transmitted, and performing retransmission according to the changed transmission mode; and selecting a layer for performing retransmission according to channel qualities of multiple layers And use the selected layer for retransmission.

Specifically, the transmission manner of changing the HARQ data packet that fails to transmit includes at least one of: changing the number of independent HARQ data packets transmitted during retransmission, changing the number of layers occupied by the HARQ data packet transmitted during retransmission, and changing the HARQ of the transmission failure. The correspondence between the data packet and the layer is retransmitted.

How to change the transmission mode of the data packet will be described in detail below.

Assume that two independent HARQ packets are transmitted through two layers for the first transmission, where layer 1 transmits data packet 1, layer 2 transmits data packet 2, and if data packet 1 is successfully transmitted and data packet 2 transmission fails, it is passed during retransmission. Layer 1 transmits the retransmitted data packet of packet 2 and transmits the empty data packet on layer 2, so that the number of layers occupied by the data packet transmitted on the two layers at the time of the first transmission is 2, and is independent at the time of retransmission. The HARQ packet occupies only one of the two layers, thereby changing the number of layers occupied by transmitting independent HARQ packets and changing the number of independent packets transmitted during retransmission. Similarly, if the retransmission packet of packet 2 is transmitted through layer 1 and layer 2 respectively during retransmission, the number of independent packets transmitted during retransmission can also be changed, since the retransmission packet of packet 2 is used to represent The independent HARQ data packet 2, and at the same time, changes the correspondence between the data packet 2 and the layer, that is, the retransmitted data packet 2 corresponds to layer 1 and layer 2.

In addition, in the case that the data packet 1 is successfully transmitted and the data packet 2 fails to be transmitted, in the retransmission, the retransmission packet of the data packet 2 transmitted on the original transport layer 2 may also be utilized by the layer 1, that is, the data packet 2 The layer corresponding to its retransmission packet is changed to layer 1, and layer 1 can be used to transmit a new data packet during retransmission, without changing the number of independent data packets at the time of retransmission and the layer occupied by the retransmission packet. Quantity, only Change the correspondence between packet 2 and the layer.

Moreover, if the channel quality of layer 2 is poor at this time, then the retransmission packet of the data packet 2 is continuously transmitted on the layer 2, and the transmission may still fail. By changing the correspondence between the data packet 2 and the layer, the data packet is made. 2 After transmission on layer 1, it will be possible to improve the transmission success rate of packet 2, thereby effectively improving the performance of retransmission.

In addition, when transmitting by using two or more layers, for example, when the data packet is transmitted through the layer 1, the data packet is transmitted through the layer 2, the data packet 3 is transmitted through the layer 3, and the data packet 4 is transmitted through the layer 4, if 4 The data packets on all the layers are all failed to be transmitted. In the retransmission, the retransmission packet of the data packet 1 can be continuously transmitted through the layer 1, and the correspondence between the other three layers and the other three data packets is modified, for example, Layer 2 transmits the retransmission packet of the data packet 4, transmits the retransmission packet of the data packet 2 through the layer 3, and transmits the retransmission packet of the data packet 2 by the layer 4, that is, modifies the correspondence between the data packet and the layer in which the partial transmission fails. .

In addition to changing the transmission mode, the layer for retransmission can also be selected according to the channel quality of the multiple layers. Here, the channel quality of the plurality of layers is obtained by channel measurement performed in advance, or obtained by channel information fed back by the receiving end.

In practical applications, two independent HARQ data packets are transmitted through two layers during the first transmission, where layer 1 transmits data packet 1, layer 2 transmits data packet 2, and channel performance of layer 1 is due to channel performance of layer 2, If the data packet 1 is successfully transmitted and the data packet 2 transmission fails, the retransmission data packet for layer 2 is transmitted according to the channel performance of layer 1 and layer 2 at the time of retransmission, and the weight of the data packet 2 is increased. Pass the success rate. Similarly, it is also possible to transmit a new data packet through layer 2 or to retransmit the data packet of packet 2 as well.

In the actual application, the retransmission policy is pre-agreed, and both the sender and the receiver are aware of the retransmission policy. When the retransmission is actually performed, the policy does not need to be separately notified, thereby effectively saving system overhead. Specifically, the method for pre-determining the retransmission policy is as follows: preset by the system and notified to the sender and the receiver; or, the policy may be pre-negotiated by the sender and the receiver. OK; or, the policy is known by the sender and the receiver in advance according to the communication protocol therebetween, without negotiation and system setting.

The retransmission mode of the present invention will be described below by taking the case of data transmission through two layers, three layers, and four layers as an example.

Example 1:

In this example, the system adopts the MIMO mode of multiple code words (MCW), and the number of independent code words is equal to 2, that is, the number of layers of the system is Layer=2, that is, the system can transmit simultaneously on two layers. Two independent HARQ data packets, and the system pre-specifies the HARQ data transmission processing mode, that is, the retransmission strategy:

In a HARQ packet corresponding to two independent codewords, when a packet transmission failure greater than or equal to one occurs for retransmission, the transmitting end exchanges the correspondence between the HARQ packet and the layer.

Figure 3 shows the retransmission strategy employed in this example. As shown in FIG. 3, the transmitting end transmits two independent HARQ data packets 1 and 2, and the HARQ data packet 1 is transmitted on Layer 1, and the HARQ data packet 2 is transmitted on Layer 2, and the HARQ data packet 1 is successfully detected at the receiving end. Packet 2 fails to be detected. After receiving the ACK and NAK of HARQ packets 1 and 2, the retransmission packet corresponding to HARQ packet 2 is transmitted on Layer 2, and a new HARQ packet 3 is transmitted on Layer 1. The HARQ packet 2 is retransmitted on Layer1, and in this transmission, the receiving end fails to detect all of the HARQ packets 2 and 3, and when the transmitting end continues to retransmit, the packet 3 is transmitted on the Layer1. Transmitting packet 2 on Layer 2, when retransmitting packet 3, transmitting the retransmission packet of packet 3 on Layer 2 and transmitting a new HARQ packet 4 on Layer 1, in this transmission. If the receiving end detects all the HARQ data packets 3 and 4 successfully, the transmitting end will transmit two new data packets on Layer 1 and 2, and if the detection fails, the retransmission is performed according to the above retransmission policy. Example 2:

In this example, the system adopts the MIMO mode of MCW, and the number of independent code words is equal to 2, that is, the number of layers of the system is Layer=2, and the system can simultaneously transmit two independent HARQ data packets on two layers, and the system pre-specifies HARQ data transmission processing mode, that is, retransmission strategy: When a packet transmission failure occurs for retransmission:

(1) If only one data packet transmission fails for retransmission, two HARQ retransmission data packets corresponding to the data packet that failed to be detected are simultaneously transmitted on Layer 1 and 2, and the format of the specific data packet is determined according to the HARQ mode. For example, for catching merged HARQ, two identical data packets are transmitted, and for incremental redundant HARQ mode, two different redundant sub-packets are transmitted.

(2) If both data packets fail to be retransmitted, the correspondence between the retransmission data packets corresponding to the two data packets that failed to be detected and the Layer is exchanged.

Figure 4 shows the retransmission strategy employed in this example. As shown in FIG. 4, the transmitting end transmits two independent HARQ data packets 1 and 2, and the HARQ data packet 1 is transmitted on Layer 1, and the HARQ data packet 2 is transmitted on Layer 2, and the HARQ data packet 1 is successfully detected at the receiving end. Packet 2 fails to be detected. After receiving the ACK and NAK of HARQ packets 1 and 2 at the transmitting end, the two retransmission packets corresponding to HARQ packet 2 are transmitted on Layer 1 and 2, and are set in this transmission. If the receiving end detects the HARQ data packet 2 successfully, the transmitting end will transmit a new HARQ data packet 3 and a HARQ data packet 4 on Layer 1 and 2 respectively, which are set in the current transmission, and the receiving end pairs the HARQ data packet 3 and 4 If the complete detection fails, when retransmitting packets 3 and 4, the retransmission packet of packet 3 will be transmitted on Layer 2, and the retransmission packet of HARQ packet 4 will be transmitted on Layer 1, in this transmission, receiving If all the HARQ data packets 3 and 4 are successfully detected, the transmitting end will transmit two new HARQ data packets 5 and 5 on Layer 1 and 2. If the detection fails, the retransmission is performed according to the above rules.

Example 3:

In this example, the system adopts the MIMO mode of MCW, and the number of independent code words is equal to 2. That is, the number of layers of the system is Layer=2, the system can simultaneously transmit two independent HARQ packets on two layers, and the system pre-specifies the HARQ data transmission processing mode, that is, the retransmission strategy: when the packet transmission fails, the weight is heavy. Time pass:

The HARQ retransmission data packet is still retransmitted on the Layer used in the first transmission, that is, the mapping relationship between the HARQ data packet and the Layer is not changed.

Figure 5 shows the retransmission strategy employed in this example. As shown in FIG. 5, the transmitting end transmits two independent HARQ data packets 1 and 2, and the HARQ data packet 1 is transmitted on Layer 1, and the HARQ data packet 2 is transmitted on Layer 2, and the HARQ data packet 1 is successfully detected at the receiving end. Packet 2 fails to be detected. After receiving the ACK and NAK of HARQ packets 1 and 2 at the transmitting end, a new HARQ packet 3 is transmitted on Layer 1, and a retransmission packet of HARQ packet 2 is transmitted on Layer 2. In this transmission, if the receiving end fails to detect the HARQ data packets 2 and 3, the HARQ data packet 3 and the HARQ data packet 2 will be retransmitted on Layer 1 and 2 respectively at the transmitting end, and the receiving end succeeds in the current transmission. Detecting packet 2, and packet 3 fails to be detected, the sender will continue to retransmit packet 3 on Layer 1, and transmit new HARQ packet 4 on Layer 2. In this transmission, the receiver is paired with HARQ packet 3. If all the detections are successful, the sender will transmit two new HARQ packets 5 and 6 on Layer 1 and Layer 2. If the detection fails, the retransmission is performed according to the above rules.

Example 4:

(1) If only one packet transmission fails for retransmission, its retransmitted packet will be transmitted on the Layer used during the first transmission, and the other Layer will be blanked, ie no data will be transmitted.

(2) If all two independent HARQ packets fail to transmit, then the number of two failed tests According to the packet, the corresponding relationship between the retransmission packet and the Layer is unchanged.

Figure 6 shows the retransmission strategy employed in this example. As shown in FIG. 6, the transmitting end transmits two independent HARQ data packets 1 and 2, and the HARQ data packet 1 is transmitted on Layer 1, and the HARQ data packet 2 is transmitted on Layer 2, and the HARQ data packet 1 is successfully detected at the receiving end. Packet 2 fails to be detected. After the ACK and NAK of HARQ packets 1 and 2 are received at the transmitting end, the retransmission packet corresponding to HARQ packet 2 is transmitted on Layer 2, and the Layer 1 is null and does not transmit any data. In the current transmission, if the receiving end detects the HARQ data packet 2 successfully, the transmitting terminal will transmit a new HARQ data packet 3 and a HARQ data packet 4 on Layer 1 and 2, respectively, in the current transmission, and the receiving end If the HARQ packets 3 and 4 fail to be completely detected, when retransmitting packets 3 and 4, the retransmission packet of packet 3 will be transmitted on Layer 1, and the retransmission packet of HARQ packet 4 will be transmitted on Layer 2. In this transmission, if the receiving end detects all the HARQ data packets 3 and 4 successfully, the transmitting end will transmit two new HARQ data packets 5 and 6 on Layer 1 and Layer 2. If the detection fails, the above rules are followed. Retransmission.

Example 5:

If only one packet transmission fails for retransmission, if the channel quality corresponding to another layer is better than the corresponding layer of the data packet, the HARQ retransmission data packet is transmitted to another layer for transmission; if two HARQ data packets are transmitted If all the transmission fails, the correspondence between the two packets that failed to be detected and the corresponding relationship between the retransmission packet and the Layer are unchanged.

Figure 7 shows the retransmission strategy employed in this example. As shown in FIG. 7, the transmitting end transmits two independent HARQ data packets 1 and 2, and the HARQ data packet 1 is transmitted on Layer 1, and the HARQ data packet 2 is transmitted on Layer 2, and the HARQ data packet 1 is successfully detected at the receiving end. data pack 2 The detection fails. After the ACK and NAK of the HARQ packets 1 and 2 are received at the transmitting end, the channel quality corresponding to the Layer 1 is better than the channel quality of the Layer 2, so the retransmission packet corresponding to the HARQ packet 2 is transmitted on the Layer 1. And transmitting a new HARQ packet 3 on Layer 2, which is set in this transmission, the receiving end fails to detect HARQ packet 2, and the HARQ packet 3 is successfully detected, and the channel quality of Layer 1 is still better than layer 2, then continue Retransmit HARQ packet 2 on Layer1 and transmit new HARQ packet 4 on Layer2. In this transmission, the receiver fails to completely detect HARQ packets 2 and 4, and the sender is in Layerl and Layer2 respectively. Retransmit packet 2 and packet 4. In this transmission, the receiver detects all HARQ packets 2 and 4 successfully, and the sender will transmit two new HARQ packets 5 and 6 on Layer 1 and Layer 2. If the detection fails, retransmit according to the above rules.

Example 6:

If only one packet transmission fails for retransmission, if the channel quality corresponding to another layer is better than the corresponding layer of the data packet, the HARQ retransmission data packet is transmitted to another layer, and the layer is not transmitted. Any data

If all the two HARQ data packets fail to be transmitted, the correspondence between the two failed test packets and the retransmission packet and the Layer are unchanged.

Figure 8 shows the retransmission strategy employed in this example. As shown in FIG. 8, the transmitting end transmits two independent HARQ data packets 1 and 2, and the HARQ data packet 1 is transmitted on Layer 1, and the HARQ data packet 2 is transmitted on Layer 2, and the HARQ data packet 1 is successfully detected at the receiving end. Packet 2 detection fails. After the ACK and NAK of HARQ packets 1 and 2 are received at the transmitting end, the channel quality corresponding to Layer 1 is better than the channel quality of Layer 2, so the HARQ data is The retransmission packet corresponding to packet 2 is transmitted on Layer 1, and no data is transmitted on Layer 2, that is, Layer 2 is blanked. In this transmission, when the receiving end detects HARQ packet 2 successfully, a new transmission is transmitted on Layer 1. HARQ packet 3, transmitting a new HARQ packet 4 on Layer 2, which is set in this transmission, the receiver fails to completely detect the HARQ packets 3 and 4, and the sender retransmits the packet on Layer 1 and Layer 2 respectively. 3 and packet 4, in this transmission, the receiver detects all HARQ packets 3 and 4 successfully, then the sender will transmit two new HARQ packets 5 and 6 on Layer 1 and Layer 2, if the detection fails. , then retransmit according to the above rules.

Example 7:

In this example, the system adopts the MIMO mode of MCW, and the number of independent code words is equal to 3, that is, the number of layers of the system is Layer=3, and the system can simultaneously transmit up to three independent HARQ data packets on three layers, and the system The HARQ data transmission processing mode is pre-defined, that is, the retransmission strategy:

When a packet transmission fails for retransmission:

(1) If only one HARQ packet transmission fails to be retransmitted, and the layer index corresponding to the HARQ packet is ( l ≤ i < 3 ), the retransmitted HARQ packet is placed on the (+1) mod3 layer. Retransmit; if there is data on the sender to send, then in addition to the

Layers other than (i' + l) mod ³ transmit new HARQ packets.

(2) If there are two independent HARQ data packet transmission failures, and the layer index corresponding to the HARQ data packet is ( l ≤ i < 3 ) ^ j ( 1 < j < 3 ), where (i ≠ j ), then two The HARQ retransmission packets are exchanged with each other using the transport layer. ;

(3) If there are three independent HARQ data packet transmission failures, and the layer index corresponding to the i-th HARQ data packet is j, the layer index corresponding to the retransmission packet of the first HARQ data packet at the time of retransmission is + l) mod3 That is, the retransmission packet of the first HARQ packet is transmitted on the +1) mod3 layer. Based on the above retransmission strategy, for example, at a certain time, the transmitting end sends three independent data packets on three layers, and the first data packet corresponds to layer 1, the second data packet corresponds to layer 2, and the third packet The data packets correspond to layer 3. When the receiving end detects, if the data packet 3 fails to be detected, and the data packets 1 and 2 are successfully received, the transmitting end transmits the weight of the data packet 3 on the layer 1 after receiving the corresponding feedback message of the three HARQ data packets. Packet transfer, transmitting new HARQ packets 4 and 5 on Layer 2 and Layer 3; thereafter, if packet 5 is successfully detected at the receiving end, and the retransmission packet and packet 4 of packet 3 still fail to be detected, then After receiving the corresponding feedback message of the three HARQ data packets, the transmitting end transmits the retransmission packet of the data packet 4 on the layer 1, transmits the retransmission packet of the data packet 3 on the layer 2, and transmits the new packet on the layer 3 HARQ packet 6; Then, at the receiving end, if the retransmission packet of the data packet 3, the retransmission packet of the data packet 4, and the data packet 6 all fail to be transmitted, the corresponding feedback of the three HARQ data packets is received at the transmitting end. After the message, the retransmission packet of the data packet 6, the data packet 4, and the data packet 3 is transmitted on the layers 1, 2, and 3 respectively. If the detection fails, the retransmission is continued according to the above rules, thereby continuously changing the retransmission packet. Correspondence with layers, can be effective High success rate of retransmission.

Example 8:

In this example, the system adopts the MIMO mode of MCW, and the number of independent code words is equal to 4, that is, the number of layers of the system is Layer=4, and the system can simultaneously transmit up to four independent HARQ data packets on four layers, and the system The HARQ data transmission processing mode is pre-defined, that is, the retransmission strategy:

When a packet transmission fails for retransmission:

(1) If only one HARQ packet transmission fails for retransmission, and the layer index corresponding to the HARQ packet is ( l ≤ i < 4 ), the retransmitted HARQ packet is placed on the (+1) mod4 layer. Retransmit; if there is data on the sender to send, then in addition to the

(i + 1) Layers other than mod 4 transmit new HARQ packets.

(2) If there are two independent HARQ data packet transmission failures, and the HARQ data packet pair The layer index should be ( l ≤ i < 4 ) ^ j ( 1 < j < 4 ), where ( j ' ), then the two HARQ retransmission packets are exchanged using the transport layer.

(3) If there are three or four independent HARQ data packet transmission failures, and the layer index corresponding to the first HARQ data packet is j, the layer index corresponding to the retransmission packet of the first HARQ data packet at the time of retransmission is + l ) mod4, that is, the retransmission packet of the first HARQ packet is transmitted on the +1) mod4 layer.

Based on the above retransmission strategy, for example, at a certain time, the transmitting end sends 4 independent data packets on 4 layers, and the first data packet corresponds to layer 1, the second data packet corresponds to layer 2, and the third packet The data packet corresponds to layer 3, and the fourth data packet corresponds to layer 4. When the receiving end detects, if the data packet 4 fails to be detected, and the data packets 1 and 2 and 3 are successfully received, the transmitting end transmits the data packet 4 on the layer 1 after receiving the corresponding feedback message of the four HARQ data packets. Retransmission packet, transmitting new HARQ packets 5, 6, and 7 on layers 2, 3, 4; thereafter, at the receiving end, if packets 4 and 5 are successfully detected, packet 6 retransmission packets and data packets 7 If the detection fails, after receiving the corresponding feedback message of the four HARQ data packets, the transmitting end transmits the retransmission packet of the data packet 7 on the layer 3, and transmits the retransmission packet of the data packet 6 on the layer 4, The new HARQ data packet 8 and the data packet 9 are transmitted on the layers 1, 2; then, at the receiving end, if all the retransmission packets, data packets 8, 9 of the data packets 6, 7 fail to be transmitted, the transmitting end is received. After the corresponding feedback messages of the four HARQ data packets, the retransmission packets of the data packet 6, the data packet 8, the data packet 9, and the data packet 7 are transmitted on the layers 1, 2, 3, and 4 respectively, and if the detection fails, the The above rules are retransmitted, thereby OFF changes the correspondence relationship between the retransmission packet and the layer.

In the above description, the transmitting end is a base station, the receiving end is a relay station or a terminal; the transmitting end is a terminal, the receiving end is a base station or a relay station; the transmitting end is a relay station, and the receiving end is a base station or a terminal. The terminal may be a mobile phone, a notebook computer, a personal computer, or the like.

It should be understood by those skilled in the art that although various examples of retransmission strategies have been described before, the present invention is not limited thereto, and in actual applications, other weights may be set as needed. Passing the strategy to retransmit the data packet, this article does not - enumerate. Moreover, although the case where only 2, 3, and 4 layers are simultaneously transmitted is described as an example, the present invention is not limited thereto, and the method of implementing the retransmission policy according to the present invention on more layers is the same as before. The manner of description is similar, and will not be enumerated in this article.

With the above processing, by retransmitting the data according to the retransmission policy, data retransmission using the same transmission mode can be avoided, and the problem of low retransmission success rate, large transmission delay, and even loss of data in the prior art is solved. Moreover, the signaling overhead occupied by the retransmission mode notification in the system can be avoided.

System embodiment:

In this embodiment, a HARQ implementation system is provided.

FIG. 9 is a block diagram of a system for implementing HARQ according to the embodiment. As shown in FIG. 9, the HARQ implementation system of this embodiment includes a transmitting end 1 and a receiving end 2.

In the system: the transmitting end 1 is configured to transmit the HARQ data packet through some or all of the multiple layers, and is used for retransmitting the HARQ data packet that fails to be transmitted according to a predetermined retransmission policy; the receiving end 2 is used for Receiving a HARQ data packet from the transmitting end, and receiving the retransmitted data packet according to the retransmission policy.

In the system, the retransmission policy may include at least one of the following: changing a transmission mode of a HARQ packet that fails to be transmitted, and performing retransmission according to the changed transmission mode; selecting, for performing weight according to channel quality of multiple layers Pass the layer and use the selected layer for retransmission.

The transmission mode of the HARQ data packet that fails to be transmitted may include at least one of the following: changing the number of independent HARQ data packets transmitted during retransmission, changing the number of layers occupied by the HARQ data packet transmitted during retransmission, and HARQ transmitting the transmission failure. The retransmission packet of the data packet is configured to correspond to other layers than the transport layer of the HARQ data packet.

In practical applications, the retransmission policy is pre-agreed, and both the sender and the receiver know the retransmission policy. When the retransmission is actually performed, the policy does not need to be notified separately, so that the scheme can be effectively implemented. Provincial overhead. Specifically, the method for pre-determining the retransmission policy is as follows: preset by the system and notified to the sending end and the receiving end; or, the policy may be determined in advance by the sending end and the receiving end; or, the policy is performed by the sending end and The receiving end knows by default according to the communication protocol in between, and does not need negotiation and system setting.

Moreover, the retransmission policies employed in the system include, but are not limited to, the retransmission policies shown in Figures 3 through 8, and are not limited to the retransmission modes described in Examples 1-8.

In addition, the transmitting end is a base station, the receiving end is a relay station or a terminal; the transmitting end is a terminal, the receiving end is a base station or a relay station; the transmitting end is a relay station, and the receiving end is a base station or a terminal. The terminal can be a mobile phone, a notebook computer, a personal computer, and the like.

With the above system, by retransmitting data according to the retransmission policy, data retransmission using the same transmission mode can be avoided, and the problem of low retransmission success rate, large transmission delay, and even loss of data in the prior art is solved. Moreover, the signaling overhead occupied by the retransmission mode notification in the system is avoided.

In summary, with the above technical solution of the present invention, the independent HARQ data packet that fails to be transmitted is retransmitted according to a predetermined retransmission policy, instead of continuing the retransmission only in the original transmission mode, thereby improving the retransmission. The success rate can also utilize the spatial diversity effect of multiple independent data stream channels to improve the diversity of the system. In addition, since the retransmission policy is predetermined, the signaling overhead occupied by the retransmission mode notification in the system can be avoided. .

Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device, or they may be separately fabricated into individual integrated circuit modules, or they may be Multiple modules or steps are made into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A method for implementing a hybrid automatic retransmission HARQ, the method comprising: the transmitting end retransmitting a HARQ data packet that fails to be transmitted according to a predetermined retransmission policy, and receiving by the receiving end.

2. The method according to claim 1, wherein the retransmission policy comprises at least one of the following:

A layer for retransmission is selected based on channel qualities of the plurality of layers, and retransmission is performed using the selected layer.

3. The method according to claim 2, wherein changing the transmission mode of the HARQ packet that fails to transmit comprises at least one of the following:

Change the correspondence between the retransmission packet and the layer of the HARQ packet that failed to be transmitted.

The method according to claim 2, wherein the channel quality of the multiple layers is obtained by pre-measurement of channel measurements or by channel information fed back by the receiving end.

The method according to any one of claims 1 to 4, wherein the predetermined retransmission policy is preset by the system and notified to the transmitting end and the receiving end;

Or the predetermined retransmission policy is determined in advance by the sending end and the receiving end; or, the predetermined retransmission policy is determined by the sending end and the receiving end according to a communication protocol therebetween. .

The method according to any one of claims 1 to 4, characterized in that, for each HARQ packet that fails to be transmitted, each of the retransmitted data packets is part of the corresponding code stream of the HARQ packet or All data is composed, and the HARQ data packets are derived from the same code stream. Each HARQ packet corresponds to the same independent HARQ packet.

The method according to any one of claims 1 to 4, wherein the transmitting end is specifically a base station, and the receiving end is specifically a relay station or a terminal;

Or the transmitting end is specifically a terminal, and the receiving end is specifically a base station or a relay station; or the transmitting end is specifically a relay station, and the receiving end is specifically a base station or a terminal.

The method according to any one of claims 1 to 4, characterized in that, for the transmitted HARQ data packet, there is a predetermined time interval between the transmission of the HARQ data packet and its retransmitted data packet, and The HARQ data packet and its retransmitted data packet occupy the same resource location in the frame structure.

A system for implementing a HARQ, the system comprising: a transmitting end and a receiving end; wherein

a sending end, configured to retransmit the HARQ data packet that fails to be transmitted according to a predetermined retransmission policy;

The receiving end is configured to receive a HARQ data packet from the sending end, and receive the retransmitted data packet according to the retransmission policy.

The system according to claim 9, wherein the transmitting end is further configured to transmit the HARQ data packet through some or all of the multiple layers.

11. The system according to claim 10, wherein the retransmission policy comprises at least one of: