WO2010094148A1

WO2010094148A1 - Method and evolution base station for hybrid automatic repeat request

Info

Publication number: WO2010094148A1
Application number: PCT/CN2009/000163
Authority: WO
Inventors: 王河; 张碧军; 胡中骥; 汪勇刚
Original assignee: 上海贝尔股份有限公司; 阿尔卡特朗讯
Priority date: 2009-02-18
Filing date: 2009-02-18
Publication date: 2010-08-26
Also published as: CN102292927A; CN102292927B

Abstract

An evolution base station for cooperation mobile communication system is disclosed. The evolution base station includes the following sub-systems: a cooperative communication sub-system, which is used for executing normal cooperative mobile communication and transmitting cooperative transmitting packets according to cooperative mobile communication protocol; a hybrid automatic repeat request (HARQ) retransmitting sub-system, which is used for executing HARQ retransmitting operation when the base station receives a message from a user equipment indicating a failure in receiving a certain cooperative transmitting packet. The HARQ retransmitting sub-system includes the following units: a congruence process unit, which processes normal cooperative transmitting packets from cooperative communication unit according to the first data format, and processes lost cooperative transmitting packets according to the second data format, a congruence packet transmitting unit, which transmits packets processed by congruence process unit, i.e. normal cooperative transmitting packets and lost cooperative transmitting packets, at the same time on same time/frequency resource.

Description

Hybrid automatic repeat request method and evolved base station

Technical field

The present invention relates to the field of mobile communications, and more particularly to cooperative mobile communication, and more particularly to a hybrid automatic repeat request (HARQ) method based on a superposition technique for a cooperative mobile communication system and a method for implementing the above HARQ method. Evolved base station. Background

Hybrid Automatic Repeat Request (HARQ) technology is an effective means to compensate for time-varying and multipath fading of wireless mobile communication channels. In wireless mobile communication systems such as 3GPP LTE and IMT-Advanced, HARQ technology is also an important Retransmission technology. With the continuous innovation of mobile communication systems, some cooperative communication enhancement schemes have been introduced in IMT-Advanced system, such as cooperative multiple input multiple output (MIM0) and cooperative single-cell point-to-multipoint (SC-PTM) evolution multimedia broadcast multicast service. (eMBMS) transmission, etc., to improve system performance. How to implement effective HARQ retransmission operations under these cooperative communication schemes remains a widely discussed issue.

In cooperative communication schemes such as cooperative MIM0 and cooperative SC-PTM eMBMS transmission, there are also situations where HARQ operations need to be applied to improve system performance. For example, Figures 1A and 1B show examples of cooperative SC-PTM schemes and cooperative MIM0 schemes, respectively.

Referring to FIG. 1A, in the cooperative SC-PTM eMBMS transmission scheme, there are some users located in the central area of the cell that cannot obtain cooperative communication gain from the cooperative cell (neighboring cell). These users are likely to experience the effects of fast depth shadow fading, for example, being obscured by buildings, and sometimes these users cannot correctly decode the received data packets. Therefore, for these SC-PTM transmission users, HARQ retransmission operations are required to improve their performance.

Referring to FIG. 1B, in the cooperative MIM0 scheme, cooperative receiving users sometimes experience instantaneous worst channel conditions, in which case the cooperative MIM0 signal cannot even be correctly received. Therefore, for these cooperative MIM0 unicast transmission users, HARQ retransmission operations are also required to improve their performance.

If the cooperative communication scheme and HARQ retransmission operation can be effectively combined, it will help solve some worst cases and be effective through HARQ gain and cooperative combining gain. Improve system performance.

Although there are multiple base stations (BSs) participating in the cooperative communication, the user equipment only responds to its serving base station with the reception status indicator of the previous packet, AC / NAC information, which will be used for the HARQ retransmission operation. The other neighboring base stations involved in the cooperative transmission did not obtain the above information. If it is desired that the HARQ retransmission operation also employs cooperative communication, it is necessary to exchange these reception status indication information between the involved BSs, and doing so will result in more signaling services and delays, failing to meet HARQ requirements. On the other hand, in cooperative communication schemes, there are also restrictions on content synchronization: It is necessary to process the same content packet data simultaneously in all BSs involved. HARQ retransmission operations for cooperative communication schemes should not disrupt such content synchronization.

The difficulties in designing appropriate HARQ retransmission operations for these cooperative communication schemes are: • In the neighboring BSs, the reception status indicator is missing – ACK/NACK information; • When performing HARQ retransmission operations, all cooperative BSs must be maintained Synchronization of the original content;

· When performing HARQ retransmission operations, the impact on normal cooperative communication transmission must be minimized;

• Low latency for HARQ retransmission operations;

• Make cooperative communication gain and HARQ gain as large as possible. Summary of the invention

In the present invention, the inventors have proposed a HARQ retransmission operation scheme for a cooperative mobile communication system such as a cooperative MIM0 system and a cooperative SC-PTM eMBMS transmission system. According to the present invention, retransmission and cooperative communication transmission are combined in a serving cell only by using a superposition technique such as hierarchical modulation, power superposition, different code rate superposition, and the like. According to the HARQ retransmission operation scheme of the present invention, the above difficulties in the design of the HARQ retransmission operation for the cooperative communication scheme can be well solved, the HARQ retransmission operation cooperates well with the cooperative communication, and the radio resources can be utilized more effectively. . According to a first aspect of the present invention, an evolved base station for a cooperative mobile communication system is provided, comprising: a cooperative communication subsystem, configured to perform according to a cooperative mobile communication protocol Normal cooperative mobile communication, transmitting cooperative transmission data packet; and hybrid automatic repeat request retransmission subsystem, for performing hybrid automatic repeat request when the user equipment feeds back an indication that a cooperative transmission data packet is not successfully received The hybrid automatic repeat request retransmission subsystem includes: an overlay processing unit, configured to process a normal cooperative transmission data packet from the cooperative communication subsystem into a first data format based on a superposition technique, and Processing the unsuccessfully received cooperative transmission data packet into a second data format; and superimposing the data transmission unit for utilizing the same time/frequency resource while simultaneously transmitting the normal cooperative transmission processed by the superposition processing unit A data packet and the cooperatively transmitted data packet that was not successfully received.

Preferably, the superposition technique is a layered modulation technique, the first data format is a basic layer, and the second data format is an enhancement layer.

Preferably, the superposition technique is a power superposition technique, the first data format is a system preset power, and the second data format is a system reserved power.

Preferably, the superposition technique is a code rate superposition technique, the first data format has a code rate, and the second data format has a second code rate greater than the first code rate.

Preferably, the hybrid automatic repeat request retransmission subsystem is in a hybrid automatic repeat request subprocess of the same number as the hybrid automatic repeat request subprocess in which the unsuccessfully received cooperative transmission data packet is located, Retransmission of a cooperative transmission data packet that was not successfully received. ·

Preferably, the maximum number of hybrid automatic repeat request retransmissions of the hybrid automatic repeat request retransmission subsystem is one.

Preferably, the cooperative mobile communication system is a cooperative multiple input multiple output mobile communication system or a cooperative single cell point-to-multipoint evolved multimedia broadcast multicast service mobile communication system. According to a second aspect of the present invention, a hybrid automatic repeat request method based on a superposition technology for a cooperative mobile communication system is provided, including: performing normal operation according to a cooperative mobile communication protocol in a serving cell and a cooperative cell Cooperative mobile communication, transmitting a cooperative transmission data packet; when the user equipment feeds back an indication that a cooperative transmission data packet is not successfully received, performing hybrid automatic retransmission only in the serving cell to which the user equipment belongs Requesting a retransmission operation, wherein the normal cooperative transmission data packet is processed into a first data format based on the superposition technique, and the cooperative transmission data packet that is not successfully received is processed into a second data format to utilize the same time/frequency resource, Simultaneously transmitting the normal cooperative transmission data packet and the unsuccessfully received cooperative transmission data packet; and in other serving cells and/or cooperative cells, performing cooperative transmission of the normal cooperative transmission data packet.

Preferably, the superposition technique is a code rate superposition technique, the first data format has a first code rate, and the second data format has a second code rate greater than the first code rate.

Preferably, in the hybrid automatic repeat request sub-process with the same number as the hybrid automatic repeat request sub-process in which the cooperatively transmitted data packet is not successfully received, performing the unsuccessfully received cooperative transmission data packet pass.

Preferably, the maximum number of hybrid automatic repeat request retransmissions is one.

Preferably, the cooperative mobile communication system is a cooperative multiple input multiple output mobile communication system or a cooperative single cell point to multipoint evolved multimedia broadcast multicast service mobile communication system. The advantages of the HARQ retransmission operation scheme based on the superposition technique according to the present invention are:

- has no effect on normal cooperative communication transmission;

- Saves total resources for HARQ retransmissions and normal cooperative communication transmissions;

- enabling HARQ retransmissions to cooperate well with cooperative communications;

- low implementation complexity; and

- In some cases, an additional cooperative combining gain for HARQ retransmission is achieved. DRAWINGS

The above and other objects, features and advantages of the present invention will become more apparent from the detailed description of the appended <RTIgt; 1A is a schematic diagram showing an example of a cooperative SC PTM scheme;

Figure IB is a schematic diagram showing an example of a cooperative MIM0 scheme;

2A is a timing diagram showing the basic operational flow of the present invention based on a cooperative SC-PTM eMBMS scheme;

2B is a functional block diagram showing an evolved base station (eNB) according to the present invention; FIGS. 3 to 5 show a case where the present invention performs a HARQ retransmission process in conjunction with an HA Q operation sub-process and a HARQ in an SC-PTM scheme. Schematic diagram of the number of retransmissions. detailed description

Hereinafter, the present invention will be described in detail based on the drawings (taking a layered modulation technique as an example). In the following description, some specific embodiments are for illustrative purposes only and should not be construed as limiting the invention. Conventional structures or configurations will be omitted when it may result in obscuring the understanding of the present invention. The invention proposes a HARQ retransmission method based on superposition technology, and different superposition techniques adopt different processing for retransmission data and normal cooperative transmission data, but the basic idea is consistent, and it is hoped that the user equipment can The combined retransmission data and the normal cooperative transmission data are correctly solved respectively. For example, based on a layered modulation technique, in which normal cooperative transmission data is used as a base layer (BL), and HARQ retransmission data is used as an enhancement layer (EL), and in the serving cell, the same time-frequency resource is used. Simultaneous transmission. The above layered modulation is performed only when a HARQ operation occurs.

Since only the serving BS can receive feedback from the user equipment regarding the reception status indicator ACK/NACK, and the BS involved in other cooperative communication does not have the above information, in order to satisfy the waiting time requirement of the HARQ retransmission operation, it cannot be involved at all. This reception status information ACK/NACK is exchanged between the BSs. Therefore, in theory, only the HARQ retransmission operation is performed in the serving cell, and there is no cooperation requirement for the HARQ retransmission operation.

However, the present invention is not a simple independent HARQ retransmission operation using another additional resource block (e.g., time-frequency resources, etc.) within the serving cell. If the HARQ retransmission packet is separately transmitted in the serving cell with additional independent resources, twice the resources are required when performing the HARQ retransmission operation, one of which is used for HARQ retransmission and the other part is used for normal cooperative transmission. . This is less efficient.

In order to keep all cooperation involved in synchronizing the original content between cells and reduce the impact on normal cooperative transmission, the inventor adopts superposition technology between HARQ retransmission and normal cooperative transmission, such as layered modulation (Li) is an optional Superposition technology. Here, an asynchronous/adaptive HARQ retransmission operation is employed. Figure 2A illustrates the basic operational flow of the present invention based on a cooperative SC-PTM eMBMS scheme. The basic idea of the present invention is: during the HARQ retransmission operation, the normal cooperative transmission in the serving cell and all the cooperative cells is maintained, and the serving cell performing the HARQ retransmission will adopt the layered modulation technique, in the same resource block, The HARQ retransmission data is modulated into an enhancement layer (EL), and the normal cooperative transmission data is modulated into a base layer (BL). Other cells are not affected by MRQ operations. HARQ retransmission data packets are not involved in cooperative transmission, so these HARQ retransmission numbers do not affect content synchronization.

In the serving cell, when HARQ operation occurs, layered modulation (abdominal) is applied to the HARQ retransmission packet and the normal cooperative transmission packet, and the base layer (BL) is used to transmit the normal cooperative transmission packet, and the enhancement layer (EL) Used to transmit HARQ retransmission packets. The base layer (BL) and the enhancement layer (EL) are layered modulated (legs) and are located on the same time-frequency resource block. Because the asynchronous/adaptive HARQ is applied, it is necessary to transmit the control signal every time the retransmission is performed, and the belly configuration information can be integrated into the control signaling and notified to the user equipment. Thus, the user equipment can simultaneously receive hierarchically modulated retransmission data and normal cooperative transmission packets from its serving cell, and only receive normal cooperative transmission packets from neighboring cells (cooperative cells). Since the normal cooperative transport packet will have a cooperative multipath combining gain, it can be decoded first as a BL, and then HM decoded as a HARQ retransmission packet of the EL.

According to the HARQ operation of the present invention, additional power resources are required to simultaneously transmit hierarchically modulated HARQ retransmission packets and normal cooperative transmission packets with the same time-frequency resources. Compared with a simple HARQ retransmission operation using independent additional resources, the present invention uses only the same time-frequency resources to simultaneously transmit HARQ retransmission packets and normal cooperative transmission packets, although a certain amount of extra power is required, but Compared to a single independent HARQ retransmission operation, the power required is much smaller.

For other candidate overlay techniques, such as power overlay techniques, consider doing When HARQ retransmits, a part of the power is allocated to the data that is normally cooperatively transmitted, and the reserved or remaining power is allocated to the retransmitted data. Moreover, in order to be able to correctly receive and decode, the data that is normally cooperatively transmitted is often allocated with higher power, and the retransmitted data is allocated with lower power, thereby achieving superposition combining. Similarly, for the rate stacking technique, a lower code rate can be assigned to the data that is normally cooperatively transmitted, and a higher code rate is assigned to the HARQ retransmitted data, and then combined. 2B is a block diagram showing the structure of an evolved base station (eNB) that can implement the HARQ retransmission operation of the present invention.

As shown in FIG. 2B, the evolved base station eNB 200 according to the present invention includes: a cooperative communication subsystem 210 for performing normal cooperative mobile communication according to a cooperative mobile communication protocol, transmitting cooperative transmission data packets; and a HARQ retransmission subsystem 220 And performing a HARQ retransmission operation when the feedback back to the indication that a cooperative transmission data packet is not successfully received. As shown in FIG. 2B, the HARQ retransmission subsystem 220 includes: an overlay processing unit 221 for processing a normal cooperative transmission data packet from the cooperative communication subsystem 210 into BL layer data based on a layered modulation technique, and The successfully received cooperative transmission data packet is processed into EL layer data; and the superimposed data transmission unit 222 is configured to simultaneously transmit the normal cooperative transmission data packet processed by the superimposition processing unit 221 by using the same time/frequency resource. The cooperatively transmitted data packet that was not successfully received.

The HARQ retransmission subsystem 220 performs retransmission of the unsuccessfully received cooperative transmission data packet in a HARQ sub-process of the same number as the HARQ sub-process in which the unsuccessfully received cooperative transmission data packet is located. Preferably, especially for cooperative SC-PTM eMBMS mobile communication systems, the maximum number of HARQ retransmissions of the HARQ retransmission subsystem 220 is one.

The eNB 200 according to the present invention can be applied to a cooperative MIM0 mobile communication system, or a cooperative SC-PTM eMBMS mobile communication system. Next, the present invention will be specifically described as follows with reference to FIG. 2A and FIG. 2B:

In the serving cell and the cooperating cell, the cooperative communication of the eNB 200 in the system 210 performs normal cooperative mobile communication according to the cooperative mobile communication protocol, and transmits the cooperative transmission data packet. The HARQ retransmission operation occurs when the UE feeds back an indication that a cooperative transmission data packet was not successfully received.

According to the present invention, the HARQ retransmission operation is performed only in the serving cell to which the UE belongs. In the HARQ retransmission operation, based on the layered modulation technique, the normal cooperative transmission data packet is processed into BL layer data, and the unsuccessfully received cooperative transmission data packet is processed into EL layer data to utilize the same time/frequency resource. And transmitting the normal cooperative transmission data packet and the unsuccessfully received cooperative transmission data packet (ie, HARQ retransmission data packet). In other serving cells and/or cooperative cells, the cooperative transmission of the normal cooperative transmission data packets is performed.

In this way, the UE can simultaneously receive the hierarchically modulated retransmission data and the normal cooperative transmission packet from its serving cell, and receive only the normal cooperative transmission packet from the neighboring cell (cooperative cell). Since the normal cooperative transport packet will have a cooperative multipath combining gain, it can be decoded first as BL, and then the HARQ retransmission packet as EL is decoded.

Further, according to the present invention, the unsuccessful execution is performed in the HARQ sub-process of the same number (jth HARQ sub-process, described later in detail) as the HARQ sub-process in which the unsuccessfully received cooperative transmission data packet is located Retransmission of received cooperative transmission data packets.

Preferably, especially for cooperative SC-PTM eMBMS mobile communication systems, the HARQ retransmission subsystem 220 has a maximum number of HARQ retransmissions of one. The reasons for this configuration will be explained in detail later. In the case of a cooperative MIM0 scheme, there is only one serving BS and the HARQ retransmission operation is performed only in its serving cell. There is no conflict between HARQ retransmission and normal cooperative transmission, and HARQ retransmission does not cause interference to other cells. Therefore, the above limitations on the original HARQ operation are eliminated. Of course, for HARQ operation, there is no cooperation gain from the neighboring cell (cooperative cell).

In the case of the cooperative SC-PTM scheme, if there are a plurality of serving BSs in the SC-PTM transmission, each of the serving BSs independently performs the HARQ retransmission operation according to its own state. HARQ operations only occur in their original HARQ sub-process, so these BSs do not have collisions in the same cell. However, this operation will sometimes cause interference in view of possible multi-cell multi-HARQ retransmission operations for the same packet. If small δ in different services If there is a HARQ retransmission of the same data packet in the zone, then for this HARQ retransmission, a cooperative combining gain will be obtained.

For example, in the SC-PTM eMBMS communication system, there are three serving cells participating in cooperative communication. Each cell has one user equipment, for example, user equipment 1 in cell 1, user equipment 2 in cell 2, and user equipment 3 in cell 3. For HARQ operations in each service cell, there are six HARQ operation sub-processes (Figure 3). For the first transmission slot, the same packet is transmitted in the same-numbered HARQ sub-process of each serving cell. BL_i, j represents the normal cooperative transmission data packet of the i-th transmission slot transmitted in the jth HARQ sub-process.

Assume that the user equipment of each cell has its own receiving error and needs to be independent.

HARQ retransmission operation. For example, the user equipment 1 in the cell 1 feeds back the NACKs of BL-1, 1 and BL-1, 3; the user equipment 2 in the cell 2 feeds back the NACKs of BL-1, 1 and BL-1, and 4; The user equipment 3 feeds back the NACKs of BL-1, 1 and BL-1, 5. Since the HARQ retransmission only occurs in the original sub-process, in the next transmission slot (the second transmission slot), the six HARQ sub-processes are as shown in FIG. In FIG. 4, BL-2, j (j=l, ..., 6) represents a new normal cooperative transmission data packet, and BL-2, j+BL-1, j represents a HARQ retransmission packet BL_1, j. Superimposed with the normal cooperative transmission packet BL-2, j. It can be seen from Figure 4 that which HARQ sub-process has NACK feedback, the HARQ retransmission operation based on the superposition technique will still and will only occur in the sub-process. From the user equipment side, some sub-processes (such as sub-process 1) also have cooperative transmission gains for HARQ retransmissions. The user equipment can also demodulate normal cooperative transmission and HARQ retransmission by using wake-up demodulation technology.

If the user equipment fails to correctly receive the first HARQ retransmission, a second HARQ retransmission for the same data is required, and at this time, in other cells, a new HARQ request for the new data packet may occur. For example, Continuing Figures 3 and 4, Figure 5 shows the transmission status of the third transmission slot. In FIG. 5, in the 1, 3, and 4 HARQ sub-processes, there is interference because different HARQ retransmission packet data are simultaneously transmitted in the same HARQ sub-process in different cells. In order to eliminate collisions between HARQ sub-processes of different cells, the maximum number of HARQ retransmissions may be limited to one, because no conflict occurs between the same HARQ sub-processes of different cells (or the same data is transmitted; or part of them) Only BL is transmitted, and another part transmits BL+EL), and interference does not occur between these serving cells. in case There is only a single serving cell, and there is no interference problem caused by multiple retransmissions mentioned above. The above examples are for illustrative purposes only and are not intended to limit the invention. It will be understood by those skilled in the art that various modifications and substitutions may be made to the embodiments without departing from the scope and spirit of the invention. In the scope.

Claims

Rights request

1. An evolved base station for a cooperative mobile communication system, comprising:

a cooperative communication subsystem, configured to perform normal cooperative mobile communication according to a cooperative mobile communication protocol, and transmit cooperatively transmitted data packets; and

a hybrid automatic repeat request retransmission subsystem, configured to perform a hybrid automatic repeat request retransmission operation when the user equipment feeds back an indication that a cooperative transmission data packet is not successfully received, where the hybrid automatic repeat request retransmission The subsystems include:

An overlay processing unit, configured to process a normal cooperative transmission data packet from the cooperative communication subsystem into a first data format based on a superposition technique, and process the unsuccessfully received cooperative transmission data packet into a second data format;

And a superimposed data transmission unit, configured to simultaneously transmit the normal cooperative transmission data packet processed by the superposition processing unit and the unsuccessfully received cooperative transmission data packet by using the same time/frequency resource.

2. The evolved base station according to claim 1, wherein the superposition technique is a layered modulation technique, the first data format is a base layer, and the second data format is an enhancement layer.

3. The evolved base station according to claim 1, wherein the superposition technique is a power superposition technique, the first data format is a system preset power, and the second data format is a system reserved power. .

The evolved base station according to claim 1, wherein the superposition technique is a code rate superposition technique, the first data format has a first code rate, and the second data format has a greater than the The second code rate of the first code rate.

The evolved base station according to any one of claims 1 to 4, characterized in that the hybrid automatic repeat request retransmission subsystem is in a hybrid automatic repeat request with the unsuccessfully received cooperative transmission data packet. In the hybrid automatic repeat request sub-process with the same number of child processes, the retransmission of the cooperative transmission data packet that is not successfully received is performed.

The evolved base station according to any one of claims 1 to 5, characterized in that the maximum number of hybrid automatic repeat request retransmissions of the hybrid automatic repeat request retransmission subsystem is 1 Times.

The evolved base station according to any one of claims 1 to 6, characterized in that said cooperative mobile communication system is a cooperative multiple input multiple output mobile communication system.

The evolved base station according to any one of claims 1 to 6, wherein the cooperative mobile communication system is a cooperative single-cell point-to-multipoint evolved multimedia broadcast multicast service mobile communication system.

9. A hybrid automatic repeat request method based on a superposition technique for a cooperative mobile communication system, comprising:

In the serving cell and the cooperative cell, performing normal cooperative mobile communication according to the cooperative mobile communication protocol, and transmitting the cooperative transmission data packet;

When the user equipment feeds back an indication that the cooperative transmission data packet is not successfully received, the hybrid automatic repeat request retransmission operation is performed only in the serving cell to which the user equipment belongs, where the normal cooperative transmission is performed based on the overlay technology. The data packet is processed into a first data format, and the cooperatively transmitted data packet that was not successfully received is processed into a second data format to utilize the same time/frequency resource while transmitting the normal cooperative transmission data packet and the unsuccessful Received cooperative transmission data packet;

In other serving cells and/or cooperative cells, the cooperative transmission of the normal cooperative transmission data packets is performed.

The hybrid automatic repeat request method according to claim 9, wherein the superposition technique is a layered modulation technique, the first data format is a base layer, and the second data format is an enhancement layer.

The hybrid automatic repeat request method according to claim 9, wherein the superposition technique is a power superposition technique, the first data format has a system preset power, and the second data format has The system reserves power.

The hybrid automatic repeat request method according to claim 9, wherein the superposition technique is a code rate superposition technique, the first data format has a first code rate, and the second data format is Having a second code rate greater than the first code rate.

The hybrid automatic repeat request method according to any one of claims 9 to 12, characterized in that the hybrid in which the data packet is transmitted in cooperation with the unsuccessful reception is automatically weighted In the hybrid automatic repeat request sub-process that requests the same number of sub-processes, the retransmission of the unsuccessfully received cooperative transmission data packet is performed.

The hybrid automatic repeat request method according to any one of claims 9 to 13, characterized in that the maximum number of hybrid automatic repeat request retransmissions is one.

The hybrid automatic repeat request method according to any one of claims 9 to 14, wherein said cooperative mobile communication system is a cooperative multiple input multiple output mobile communication system.

The hybrid automatic repeat request method according to any one of claims 9 to 14, wherein the cooperative mobile communication system is a cooperative single-cell point-to-multipoint evolved multimedia broadcast multicast service mobile communication system.