KR20090075081A - Methods of transmitting and receiving data in communication systems - Google Patents

Abstract

A method for transceiving data in a communication system is provided to enhance data transmission efficiency by minimizing the number of response signals, which are linearly increased, and enabler a receiver to transmit the response signal with the minimum resources. At least one grouped data block is received from more than one transmitter. It is checked whether more than one data block included in each group is successively received or not. First control signal including an index, which points a response signal for at least one data block selected from an index table, is transmitted to at least one transmitter. The index table is a combination of the response signal for at least one data block.

Description

Methods of transmitting and receiving data in communication systems

The present invention relates to a communication system, and more particularly, to a method for transmitting and receiving a response signal in a mobile communication system.

When an error occurs during communication, general methods for overcoming this problem include automatic repeat request (ARQ) and error correction. When an error occurs during duplex communication, the receiving side notifies the transmitting side of the error, and the transmitting side retransmits the data block in which the error occurs. This is called ARQ. Typical examples of the ARQ method include a stop-and wait ARQ, There is continuous ARQ, adaptive ARQ. ARQ requires an inverse channel to feed back and an ARQ system must remember the data block being transmitted, so a buffer is necessary.

1 is a diagram illustrating an operation principle of a stop-and-wait HARQ technique. As shown in FIG. 1, the transmitting side Tx transmits a data block corresponding to the index '1', and the receiving side Rx receives the data block corresponding to the index '1' and then ACK ( ACKnowledgement) / NAK (No ACK) is determined, and the determination result is transmitted to the transmitting side. If the transmitting side Tx receives the NAK signal, the transmitting side transmits the data block corresponding to the index '1' to the receiving side again. In the stationary and standby ARQ schemes, transmission efficiency is not good because the next data block cannot be transmitted until one data block is transmitted until an ACK or NAK is received. In order to overcome this drawback, when a NAK is received indicating that an error has occurred at the receiving end after continuously transmitting data blocks, a method of retransmitting all blocks after an error or retransmitting only the corresponding block having an error is called continuous ARQ. . Continuous ARQ is effective when applied to a system with a long propagation delay (no ACK is sent and a NAK is sent only when an error occurs). There are two types of continuous ARQ methods: Go-Back-N ARQ and Selective-Repeat ARQ. have.

Go-Back-N ARQ transmits N consecutive data blocks, and if the transmission is not successful, all data blocks transmitted after the data block in error is retransmitted. The Selective-Repeat ARQ technique selectively retransmits only the data block in which an error occurs. This ARQ technique can be combined with an error correction technique to provide more efficient error control. This is described below.

Hybrid Automatic Repeat reQuest (HARQ) is a technology that controls errors by combining retransmission and error correction. It maximizes the error correction code capability of data received during retransmission. The error correction technique includes Backward Error Correction (BEC), which is a method of transmitting a block of data that is again failed by the sender to recover a block of data that is in error, and the sender receives the error from the receiver. There is a recovery technique of Forward Error Correction (FEC). In general, the error correction technique in HARQ is a lot of forward error correction technique. When HARQ is used, when the receiver fails to recover the data block, the receiver may request retransmission to the transmitter and combine the retransmitted data with the stored data before the decoding process to achieve better performance. Stop and Standby HARQ, which is widely used as the ARQ technique used in HARQ, is the simplest and most efficient transmission method, but the rounding trip time until the transmitting side of the data transmits and receives the ACK / NAK from the receiving side of the data. This decreases the link transmission efficiency. To compensate for this, N-channel stop and standby HARQ protocol techniques are used.

2 is a diagram illustrating the basic operation of the N-channel stop and standby HARQ technique in the prior art. The N channel stop and standby HARQ of FIG. 2 operates a plurality of (N) independent stop and standby HARQs during a time when a transmission link is not used until an ACK / NAK is exchanged. In general, in the stationary and standby HARQ scheme, the data receiver checks whether the data is successfully received through an error detection code such as a cyclic redundancy check (CRC). For convenience, in the present invention, a data unit capable of detecting an error is called a HARQ process block. If an error of data is not detected, the receiving side transmits an ACK signal, and if an error is detected, the receiving side transmits a NAK signal. The data transmitting side receiving the ACK signal then transmits the data. The data sender receiving the NAK signal retransmits the data in error. Meanwhile, when the transmission bandwidth is wide or when data is transmitted using multiple antennas, a plurality of HARQ process blocks may be transmitted. That is, a plurality (m) of HARQ Process blocks may be simultaneously transmitted during a predetermined space, frequency, wave source, time, or time interval.

3 is a diagram illustrating an operation when a plurality of HARQ process blocks are transmitted. The receiving side receiving data may transmit m ACK / NAK signals for m HARQ process blocks to the data transmitting side.

As discussed above, as the number of HARQ process blocks simultaneously transmitted in unit time increases, the resource for transmitting ACK / NAK increases linearly, thereby increasing the overhead of a control signal including a response signal, thereby improving system efficiency. Results in deterioration.

An object of the present invention has been proposed to solve the above problems of the prior art, an object of the present invention is to provide a method for transmitting and receiving data in a communication system.

Another object of the present invention is to provide a method for transmitting and receiving a response signal to a transmission signal in a mobile communication system.

One aspect of the invention discloses a method for transmitting a response signal to a transmission signal at a receiving side of a communication system. To this end, it receives at least one data block from at least one transmitting side, checks whether each block has been successfully received for the at least one data block, and combines a response signal for at least one data block. The first control information including an index indicating a response signal for the at least one data block selected from the index table is transmitted to the at least one transmitting side.

Another aspect of the invention discloses a method for receiving a response signal in response to a transmission signal at a transmission side of a communication system. To this end, second control information including index information indicating a response signal of the at least one data block selected from an index table, which is a combination of response signals for at least one data block from at least one receiving side, may be obtained. Receive and check whether each data block was successfully transmitted through the response signal for the at least one data block.

Preferably, the index table comprises a combination of response signals for the at least one data block by the number of indexes determined according to the retransmission probability for the data block and the number of concurrently processed data blocks.

Preferably, the retransmission probability is determined using control information including information indicating the channel state transmitted by the transmitting side or determined by checking the channel state at the receiving side.

Preferably, the index table necessarily includes a case in which all of the response signals for the at least one data block are ACK (ACKnowledgement) and all NAK (Not ACK).

Preferably, the index table preferentially includes a case where there are many ACK signals as response signals to the at least one data block when the retransmission probability is smaller than a predetermined value.

Preferably, the index table preferentially includes a case where there are many NAK signals as response signals for the at least one data block when the retransmission probability is greater than a predetermined value.

Preferably, when there is no response signal for the at least one data block in the index table, all of the response signals for the at least one data block are NAK.

Preferably, receiving control information including information indicating the use of the response signal transmission method using the index table from the transmitting side or requesting the transmission side to use the response signal receiving method using the index table. Send control information including information.

In the mobile communication system according to the present invention, the following effects can be obtained through a method of transmitting and receiving a response signal to a transmission signal.

First, data transmission efficiency can be improved by minimizing the number of linearly increasing response signals.

Secondly, when the receiving party to which the response signal is to be allocated does not properly allocate the resources for the response signal from the transmitting side, it can respond using the minimum resources.

The construction, operation, and other features of the present invention will be readily understood by the embodiments of the present invention described with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The embodiments described below are examples of the technical features of the present invention applied to an Evolved Universal Mobile Telecommunications System (E-UMTS), also called Long Term Evolution (LTE), and other similar features such as IEEE 802.16m and Wibro systems. Applicable to mobile communication systems as well.

The E-UMTS system is an evolution from the existing WCDMA UMTS system and is currently undergoing basic standardization work in the 3rd Generation Partnership Project (3GPP). For details of technical specifications of UMTS and E-UMTS, refer to Release 7 and Release 8 of the "3rd Generation Partnership Project; Technical Specification Group Radio Access Network", respectively.

The following techniques can be used in a variety of communication systems, including ways of using multiple antennas.

Communication systems are widely deployed to provide various communication services such as voice, packet data, and the like. This technique can be used for downlink or uplink. Downlink means communication from the base station to the terminal, uplink means communication from the terminal to the base station. A base station generally includes a network excluding a terminal in a communication system that includes not only a physical transmission end but also an upper layer as a fixed point for communicating with a terminal. Therefore, in the present invention, the network and the base station have the same meaning as symmetrical parts with the terminal. The terminal may be fixed or mobile. The present invention can be used in a single carrier or multi-carrier communication system. The multi-carrier system may use orthogonal frequency division multiplexing (OFDM) or another multi-carrier modulation technique.

An embodiment of the present invention proposes a method of minimizing resource allocation for a response signal according to a channel state when simultaneously transmitting a plurality (m) HARQ process blocks to which a stop and standby HARQ is applied at a unit time.

4 is a diagram illustrating a method of transmitting and receiving an index response signal according to an embodiment of the present invention. As described above, the HARQ process represents a unit of data in which an error can be detected. Data that can be divided into units that can detect each error when one user transmits and receives data have respective HARQ process IDs and are distinguished from each other through these HARQ processes, which are classified into user IDs according to specific users. Therefore, it may have a duplicate HARQ process ID. When the transmission bandwidth is sufficiently wide, a plurality of HARQ process blocks may be generated and transmitted by operating a plurality of HARQ processes in one user unit. In addition, in a communication system provided with a plurality of transmitting antennas, the HARQ process block may include HARQ process blocks that independently transmit data of data that can be simultaneously transmitted based on the number of physical antennas or the number of virtual layers, that is, a data unit capable of error detection. It may be classified according to the number. The plurality of HARQ processes may be coded by different channel coding methods or coded by the same channel coding method. If coded by the same channel coding method, each HARQ process block may be coded according to an arbitrary coding rate.

Systems may use various channel coding techniques, modulation schemes, or transmit different sizes of data in consideration of channel conditions. Therefore, in general, the probability of occurrence of ACK / NAK is different and the probability of occurrence of ACK increases. Accordingly, the probability of generating combinations of response signals ACK / NAKs for m HARQ process blocks transmitted simultaneously by applying the stop and standby HARQs is different. Therefore, if the channel environment is good, it is not necessary to secure m radio resources even though some NAKs occur in m process blocks. The reason for securing m-bit radio resources is to prepare for all cases of ACK and NAK signals of m HARQ process blocks. Although NAKs occur in some HARQ process blocks, the response to m HARQ process blocks is sufficiently high even with fewer radio resources without continuing to acquire m radio resources (for example, m bits). can do. This may result in greater radio resource savings when multiple HARQ process blocks are simultaneously transmitted on each transmitting side connected to each antenna in a multi-antenna system. Or, in general, when a terminal receives resource information for a response signal through a control signal from a network, when the terminal is not allocated or fails to receive it because of data congestion, the terminal may allocate a minimum radio resource by itself and transmit a response signal.

For a more clear operation, when the network or the terminal determines that the channel environment is good for a predetermined time or more, the network or the terminal may transmit a control signal for requesting the response table resource allocation method of the index table method proposed by the present invention to the other party. When the receiving side receives the control signal as described above, the resource allocation of the response signal is allocated to the index table method proposed in the present invention, thereby optimizing the resource amount of the control data, thereby increasing the ratio of payload data. The request control signal may be allocated and transmitted to a common channel such as system information or a random access channel (RACH), and may be transmitted and received on a dedicated channel or a separate new channel.

In m HARQ process blocks transmitted simultaneously, the number of resources for an average required response signal according to a transmission success rate may be expressed as an expected value as shown in Equation (1).

If m HARQ process blocks all generate ACK in Equation 1, other combinations are not required, and thus, only one unit size (in the present invention, 1 bit) may be transmitted in the system. Otherwise, this is the expected value when it is assumed that m bits are required to represent each ACK / NAK. p means the probability that the transmission data is successfully received at the receiving side. m means the number of HARQ process blocks transmitted at the same time. N means the average number of radio resource bits required for the ACK / NAK response when the transmission success probability is p and m HARQ process blocks are transmitted simultaneously. M is an integer of 2 or more. That is, it can be used when the number of HARQ processes transmitted simultaneously is two or more. If m size is 1, ACK / NAK response signal is expressed in unit size.

Table 1 shows the average number of bits required for transmission of the expected response signal when Equation 1 is applied while varying the number of HARQ process blocks processed simultaneously with the transmission success probability.

Number of HARQ process blocks processed at the same time 2 3 4 5 10 p (the probability that the transfer will succeed) 0.7 1.51 2.31 3.23 4.33 9.75 0.8 1.36 1.98 2.78 3.69 9.03 0.9 1.19 1.54 2.03 2.64 6.86 0.99 1.02 1.06 1.12 1.20 1.86

As shown in Table 1, as the transmission success rate increases and the number of HARQ process blocks increases, the average expected number of response signals decreases. Since resource allocation for response signals must be expressed as integer values, rounding, rounding, or rounding can be applied to the values obtained in Table 1.

That is, in the present invention, the size of a radio resource required for transmitting a response signal such as an ACK / NAK for data such as an HARQ process block transmitted simultaneously from the transmitting side at the receiving side is equal to the success rate of the data transmission as shown in Equation 1. It can be expressed as a function of the number of data processed.

In an embodiment of the present invention, it is assumed that the number of radio resources required for response signal allocation is determined by rounding the values obtained in Table 1 according to the number of simultaneous HARQ process blocks and the transmission success rate.

Next, a response table for expressing a response signal for more HARQ process blocks with the number of bits obtained through this is constructed. If the number of bits obtained is n, there are a total of 2 ⁿ response table elements. Assign an index to this element from 0 to 2 ⁿ -1. In the case where all of the response signals for the HARQ process block are ACK and all are NAK, it is assumed to be allocated to indexes 0 and (2 ⁿ -1). All ACKs are allocated because they are most likely to occur. All NAKs are used when the size of the table is too small to represent all combinations. This is to increase the reliability of.

The remaining 2 ^n- 2 (응답 (2 ⁿ -2)) are allocated response signals for HARQ process blocks. In this case, if the combination of the generated ACK / NAK response signals is not in the response table, all cases are NAK. Index number (2 ⁿ -1) is transmitted, and both the transmitting side and the receiving side indicate that NAK has occurred.

An embodiment of the present invention proposes a method of allocating response signals for m HARQ process blocks to remaining indexes except index 0 and index 2 ⁿ -1 in an index table.

In theory, by operating m HARQ process blocks, a combination of 2 ^m response signals is possible. However, the index table according to the number of response signal bits (assuming n) determined by Equation 1 proposed in the embodiment of the present invention has only 2 ⁿ components.

As Table 1 shows, the smaller the probability of retransmission (i.e., the higher the probability of success) and the larger m, the smaller the value of n compared to the value of m, so that the combination of response signals for the actual HARQ process block is obtained. Since it may not be possible, an efficient configuration method is required.

The larger the transmission success probability p, the smaller n is required than m. However, since p is large, it is estimated that the channel environment is good. Therefore, except for the case of all ACK and all NAK previously allocated in the index table, the remaining index table is allocated with the highest possible combination first. In this case, a random order may be assigned or a random order may be assigned to a combination having the same probability of occurrence.

In the response method using the index table, the terminal and the network of the system may determine a predetermined number of fixed tables according to the transmission success probability p or notify the terminal from the network through system information. In the latter case, the index table can be changed and used between the network and the terminal based on the channel environment in a certain section. In more detail, the transmission side accumulates the ACK, NAK distribution ratio of the response signal at a certain time or interval from the reception side to determine the transmission success probability or CINR (carrier to interference and noise ratio) of a specific channel. ) Or based on a received signal strength indicator (RSSI) value, or the receiving side may determine a transmission success probability by analyzing a channel environment through a pilot signal of the transmitting side.

According to the determined transmission success probability, if the network transmits index table information corresponding to the terminal through system information or the like, and if the network transmits control information indicating the determined transmission success probability to the terminal, the terminal is an index table embedded therein. It is possible to use the same index table as the network.

Tables 2 to 10 illustrate the configuration of the index table in a method of determining the number of response signals determined by Equation 1 and Table 1 by rounding while changing the retransmission probability and the number of HARQ process blocks transmitted simultaneously under a multi-antenna system. Embodiments proposed in the present invention.

Table 2 is an example of an index table when two HARQ process blocks are used when the retransmission probability is 30%, that is, when the transmission success probability p is 0.7. Since the number of response signals determined through rounding is the same as the number of HARQ process blocks, in this case, the index table has a combination of all possible response signals. The receiving side transmits index information having a combination corresponding to the response signal of the current process block in the index table to the transmitting side through the 2-bit response signal index information. In Table 2, a stream may mean each data stream constituting data transmitted to one user when the transmission bandwidth is large enough, or may mean each data stream transmitted to a plurality of users. In addition, in a communication system equipped with a plurality of transmit antennas may mean a data stream that is transmitted at the same time and each of the independent error detection, in the following embodiments it means each HARQ process block transmitted from the m transmit antennas. The following tables have the same meaning.

index Stream 1 Stream 2 0 ACK ACK One ACK NAK 2 NAK ACK 3 NAK NAK

Table 3 shows an example of an index table when three HARQ process blocks are used when the retransmission probability is 30%, that is, when the transmission success probability p is 0.7. Eight combinations occur with the total number of combinations 2 ³ . Table 3 shows the possible combinations of response signals for the entire stream and the probability that the combination will occur.

index Stream1 Stream2 Stream3 Probability of occurrence 0 ACK ACK ACK 0.343 One ACK ACK NAK 0.147 2 ACK NAK ACK 0.147 3 ACK NAK NAK 0.063 4 NAK ACK ACK 0.147 5 NAK ACK NAK 0.063 6 NAK NAK ACK 0.063 7 NAK NAK NAK 0.027

Table 4 is determined by the number of HARQ process blocks processed simultaneously with p in Equation 1 when three HARQ process blocks are used when the retransmission probability is 30%, that is, when the transmission success probability p is 0.7. It is an example of an index table reflecting the number of combinations of response signals determined by rounding a value.

 Since the number of response signals determined through rounding is smaller than the number of HARQ process blocks, a table is configured according to the present invention described above. First, all cases of ACK are assigned to index 0, and all cases of NAK are assigned to index 3. Since the other two cannot express all three cases in which only one NAK is represented in three HARQ process blocks, they can be configured as shown in Table 4 or configured differently.

index Stream 1 Stream 2 Stream 3 0 ACK ACK ACK One ACK ACK NAK 2 NAK ACK ACK 3 NAK NAK NAK

Table 5 shows an example of an index table when four HARQ process blocks are used when the retransmission probability is 30%, that is, when the success probability p is 0.7. Since the number of response signals determined through rounding is smaller than the number of HARQ process blocks, a table is configured according to the present invention described above. First, all cases of ACK are assigned to index 0, and all cases of NAK are assigned to index 7. Index 1 to index 4 place only one process block response signal as NAK, and index 5 to index 6 place case where two process block response signals are NAK, but not all combinations represent all cases. Although the channel characteristics in the transmission process are bursty, it is possible to consider a method of arranging the ACK signal and the NAK signal in succession.

index Stream 1 Stream 2 Stream 3 Stream 4 0 ACK ACK ACK ACK One ACK ACK ACK NAK 2 ACK ACK NAK ACK 3 ACK NAK ACK ACK 4 NAK ACK ACK ACK 5 ACK ACK NAK NAK 6 NAK NAK ACK ACK 7 NAK NAK NAK NAK

Table 5 shows an example of an index table when four HARQ process blocks are used when the retransmission probability is 20%, that is, when the success probability p is 0.8. The following is the same as in the case of Table 5.

index Stream 1 Stream 2 Stream 3 Stream 4 0 ACK ACK ACK ACK One ACK ACK ACK NAK 2 ACK ACK NAK ACK 3 ACK NAK ACK ACK 4 NAK ACK ACK ACK 5 ACK ACK NAK NAK 6 NAK NAK ACK ACK 7 NAK NAK NAK NAK

Table 6 shows an example of an index table when four HARQ process blocks are used when the retransmission probability is 10%, that is, when the success probability p is 0.9. Since the channel environment is assumed to be good, the number of response signals determined by rounding is two less than the number of HARQ process blocks. This also constitutes a table according to the present invention described above. First, all cases of ACK are assigned to index 0, and all cases of NAK are assigned to index 3. In the case of the index 1 to the index 2, only one process block response signal is NAK, but not all of the combinations thereof may be arranged as shown in Table 4 below.

index Stream 1 Stream 2 Stream 3 Stream 4 0 ACK ACK ACK ACK One ACK ACK ACK NAK 2 NAK NAK ACK ACK 3 NAK NAK NAK NAK

The present invention can be applied not only to a good channel environment having a high probability of transmission success but also to a high probability of transmission failure due to a bad channel environment. If the channel environment is bad, as opposed to the channel environment, the probability of generating a NAK signal is high. Therefore, the number of response signals required according to the number of m HARQ processes based on the probability q of transmission failure is expressed by Equation 2.

If m HARQ process blocks all generate NAK in Equation 2, other combinations are not necessary, and thus, only one unit size (in one embodiment of the present invention) may be transmitted in a system because one system requires one ACK / NAK transmission. Otherwise, this is the expected value when it is assumed that m bits are required to represent each ACK / NAK.

In Equation 2, q means the probability that the transmission data is unsuccessfully received at the receiving side. m means the number of HARQ process blocks transmitted at the same time. N is the number of expected radio resource bits required for the ACK / NAK response when the probability of transmission failure is q and simultaneous transmission of m HARQ process blocks.

Table 8 shows the number of response signal bits when Equation 2 according to the transmission failure probability q and the number of HARQ process blocks is applied.

Number of HARQ process blocks processed at the same time 2 3 4 5 10 q (probability of retransmission) 0.7 1.51 2.31 3.23 4.33 9.75 0.8 1.36 1.98 2.78 3.69 9.03 0.9 1.19 1.54 2.03 2.64 6.86 0.99 1.02 1.06 1.12 1.20 1.86

Table 8 can be seen that the same as Table 1.

Table 9 is an example of an index table when four HARQ process blocks are used when the retransmission probability is 80%, that is, when the probability of failure q is 0.8. Since the number of response signals determined through rounding is smaller than the number of HARQ process blocks, a table is configured according to the present invention described above. Instead, since the probability of retransmission is high, the case of all NAKs is assigned to index 0 and the case of all ACKs to index 7 is assigned. In the case of index 1 to index 4, the case where only one process block response signal is ACK is arranged. In the case of index 5 to index 6, the case where two process block response signals are ACK is arranged, but the combination cannot be represented. Although the channel characteristics in the transmission process are bursty, it is possible to consider a method of arranging the ACK signal and the NAK signal in succession.

Alternatively, if the channel environment is good or bad, the same index table can be used to prevent the growth of the index table. Table 9 below shows the configuration of the index table in the case where the index table is divided by distinguishing the case where the channel environment is good or bad based on a specific criterion to express the present invention in various ways.

index Stream 1 Stream 2 Stream 3 Stream 4 0 NAK NAK NAK NAK One NAK NAK NAK ACK 2 NAK NAK ACK NAK 3 NAK ACK NAK NAK 4 NAK NAK NAK NAK 5 NAK NAK ACK ACK 6 ACK ACK NAK NAK 7 ACK ACK ACK ACK

As described above, it is obvious that the index table can be configured as in the case where the channel environment is good by varying the probability of failure and the number of HARQ process blocks.

In the above-described embodiment of the present invention, a case of transmitting data using multiple antennas, regardless of whether a case of transmitting different data blocks in multiple antennas or transmitting the same data block for diversity Application is possible. Next, a case of applying the present invention to the continuous ARQ will be described.

In the Go-Back-N ARQ scheme among the continuous ARQ schemes, the transmitting side continuously transmits data blocks having a specific window size. When the receiver detects an error in the received data blocks, the receiver transmits the sequence number of the data block in which the error occurred together with the NAK signal to the transmitter. Receiving the NAK, the transmitting side retransmits the frames of the window size to the receiving side continuously from the data block corresponding to the sequence number transmitted together with the NAK. Go-Back-N ARQ Method Unlike stop and standby ARQ, the number of response signals is not as high as that of stop and standby ARQ because instead of waiting for a response signal after transmitting one data block, the next data block is continuously transmitted until a NAK response signal is received. Although not required, in combination with the multi-antenna mode, when transmitting a response signal, whether ACK or NAK for the data block at each antenna, optimization of radio resources is required, and when the resource of an appropriate response signal is not allocated from the network. The application of the present invention is also possible in that it is necessary to secure radio resources for the minimal response signal. The same is true of selective repetitive ARQ, which is another way of continuous ARQ. In the selective repetitive ARQ, unlike the Go-Back-N ARQ in which the transmitter continuously retransmits the data block from which the NAK is received, only the data block corresponding to the NAK is retransmitted. Can be.

In addition, the present invention can be applied to the adaptive ARQ scheme, which can dynamically change the length of the data block to be transmitted in order to maximize transmission efficiency. The adaptive ARQ method sends a shorter block if the error rate is high and the data block retransmission request from the receiver is large. If the data block retransmission request rate is small from the receiver, a long block length is sent. to be. It detects the error rate in the receiving channel and informs the transmitting side. Based on this information, the transmitting side determines the length of the most suitable data block and transmits the data block. When the adaptive ARQ is used in combination with the N-channel stop and standby HARQ or the continuous ARQ under the multi-antenna system, the present invention can be applied with respect to resource acquisition of the response signal. That is, when transmitting a plurality of separate HARQ process blocks from each antenna to each antenna, the present invention can be applied to resource allocation of response signals for data blocks according to retransmission probabilities.

In the above detailed description, the process of performing communication between the transmitting side and the receiving side has been described mainly for the convenience of description of the present invention and its embodiments, but the transmitting side may be a base station or a base station of a network, and a constant receiving side may be a base station or a terminal of a network. have. The terminology used herein may be replaced with other terms having the same meaning. For example, a terminal may be replaced with a mobile station, mobile terminal, communication terminal, user equipment or device, and the like, and a base station may be replaced with terms such as a fixed station, a Node B (NB), an eNB, and the like.

It is apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention. Accordingly, the above detailed description should not be interpreted as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

1 is a block diagram illustrating an operating principle of a stop-and-wait HARQ technique.

2 is a diagram illustrating the basic operation of the N-channel stop and standby HARQ technique in the prior art.

3 is a diagram illustrating an operation when a plurality of HARQ process blocks are transmitted.

4 is a diagram illustrating a method of transmitting and receiving an index response signal according to an embodiment of the present invention.

Claims (17)

In the method for transmitting a response signal to the transmission signal at the receiving side of the communication system, Receiving at least one data block from at least one transmitting side; Checking whether each block has been successfully received for the at least one data block; And Transmitting first control information to the at least one transmitting side, the first control information including an index indicating a response signal for the at least one data block selected from an index table that is a combination of response signals for at least one data block; The method for transmitting a response signal to the transmission signal at the receiving side of the communication system comprising a. The method of claim 1, And the index table comprises a combination of response signals for the at least one data block corresponding to the number of indexes determined according to the retransmission probability for the data block and the number of concurrently processed data blocks. A method of transmitting a response signal in response to a transmission signal at a receiving side of the system. The method of claim 2, The retransmission probability is determined by using second control information including information indicating the channel state transmitted by the transmitting side or determined by checking the channel state at the receiving side. How to send a response signal for. The method of claim 2, The index table necessarily includes a case where all of the response signals for the at least one data block are ACK (ACKnowledgement) and all NAK (Not ACK), the response to the transmission signal at the receiving side of the communication system How to send a signal. The method of claim 4, wherein The index table preferentially includes a case in which there are many ACK signals as response signals for the at least one data block when the probability of retransmission is smaller than a predetermined value. How to transfer. The method of claim 4, wherein The index table preferentially includes a case in which there are many NAK signals as response signals for the at least one data block when the retransmission probability is greater than a predetermined value. How to transfer. The method according to claim 5 or 6, If the response signal for the at least one data block does not exist in the index table, the response signal for the at least one data block is processed as if all of the response signals are NAK. How to send a signal. The method of claim 1, Receiving third control information including information indicating the use of the response signal transmission method using the index table from the transmission side or information requesting the transmission side to use the response signal reception method using the index table; And transmitting at least one of the steps of transmitting the fourth control information including a response signal to the transmission signal at the receiving side of the communication system. In the method for receiving a response signal to the transmission signal at the transmission side of the communication system, Receiving fifth control information including index information indicating a response signal of the at least one data block selected from an index table which is a combination of response signals for at least one data block from at least one receiving side; ; And Checking whether the at least one data block transmitted by the transmitting side to the at least one receiving side is successfully transmitted through the fifth control information; How to. The method of claim 9, And the index table comprises a combination of response signals for the at least one data block corresponding to the number of indexes determined according to the retransmission probability for the data block and the number of concurrently processed data blocks. A method for receiving a response signal to a transmission signal at the transmission side of the system. The method of claim 10, The retransmission probability is determined by the transmitting side by checking the channel state or by using the sixth control information including information indicating the channel state transmitted by the at least one receiving side. Receiving a response signal for a transmission signal in a. The method of claim 9, And determining whether to retransmit the at least one data block or transmit a new data block to the receiving side according to the fifth control information. How to receive a signal. The method of claim 10, The index table necessarily includes a case in which all of the response signals for the at least one data block are ACK (ACKnowledgement) and all NAK (Not ACK). How to receive a signal. The method of claim 13, The index table preferentially includes a case in which a large number of ACK signals is used as a response signal for the at least one data block when the retransmission probability is smaller than a predetermined value. How to receive it. The method of claim 13, The index table preferentially includes a case in which there are many NAK signals as response signals for the at least one data block when the retransmission probability is greater than a predetermined value. How to receive it. The method according to claim 14 or 15, If the response signal for the at least one data block is not in the index table, the response signal for the at least one data block is processed as if all of the response signals are NAK. How to receive a signal. The method of claim 16, Transmitting the seventh control information including information indicating the use of the response signal transmission method using the index table to the receiving side, or information requesting the use of the response signal reception method using the index table from the receiving side; And receiving at least one of a step of receiving an eighth control information comprising the response signal in response to the transmission signal at the transmission side of the communication system.

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