KR20070099369A - Method and system for transmitting data in a communication system - Google Patents

Abstract

A method and a system for transmitting data in a communication system are provided to enhance data transmission efficiency by increasing the number of reception acknowledgement blocks to be transmitted. When a transmitter(301) receives SDU(Service Data Unit) data from an upper layer(311), a timer is activated(313) to detect a generation of an ARQ_SYNC_LOSS_TIMEOUT. When the timer is activated, the transmitter transmits a MAC(Media Access Control) PDU(Protocol Data Unit) to a receiver(315). When the receiver(303) receives the MAC PDU, a timer for detecting the ARQ_SYNC_LOSS_TIMEOUT is activated, and the received MAC PDU is decoded(317). The receiver transmits a decoded result to the transmitter.

Description

METHOD AND SYSTEM FOR TRANSMITTING DATA IN A COMMUNICATION SYSTEM}

1 is a diagram schematically showing the structure of a general IEEE 802.16e communication system.

2A and 2B schematically illustrate transmission and reception data in a communication system to which the ARQ scheme is applied according to an embodiment of the present invention.

3 is a diagram illustrating an ARQ operation process between a transceiver in a communication system according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system, and more particularly, to a method and a system for transmitting data in a communication system to which an automatic repeat request (ARQ) method is called.

In the 4th generation (4G) communication system, which is a next generation communication system, users having services having a variety of high-speed services of quality (QoS) are referred to as users. Active research is underway to provide it. In particular, in the current 4G communication system, a wireless local area network (LAN) system and a wireless metropolitan area network (MAN) system are called. Researches are being actively conducted to support high-speed services in a form of guaranteeing mobility and QoS in a broadband wireless access (BWA) communication system such as Representative communication systems are the Institute of Electrical and Electronics Engineers (IEEE) 802.16a / d communication system and the IEEE 802.16e communication system.

The IEEE 802.16a / d communication system and the IEEE 802.16e communication system, which are the BWA communication system, orthogonal frequency division multiplex (OFDM) to support a broadband transmission network on a physical channel of the wireless MAN system. Division Multiplexing (hereinafter referred to as "OFDM") / Orthogonal Frequency Division Multiple Access (OFDMA) scheme is a communication system that applies. The IEEE 802.16a / d communication system currently considers only a single cell structure and a state in which a subscriber station (SS) (hereinafter referred to as SS) is fixed, i.e., does not consider SS mobility at all. System. In contrast, the IEEE 802.16e communication system is a system considering the mobility of the SS in the IEEE 802.16a communication system, and the SS having the mobility is referred to as a mobile station (MS). Shall be. Next, the structure of the IEEE 802.16e communication system will be described with reference to FIG. 1.

1 is a diagram schematically illustrating a structure of a general IEEE 802.16e communication system.

Referring to FIG. 1, an IEEE 802.16e communication system has a multi-cell structure, that is, a cell 1 (100) and a cell 2 (150), and a base station (BS: Base) that manages the cell 1 (100). Station 1 (110), BS2 (160) that manages the cell 2 (150), a plurality of MSs that are provided with communication services from the BS1 (110) and BS2 (160), that is, MS1 (111), MS2 (113), MS3 (130), MS4 (151), and MS5 (153). In addition, signal transmission and reception between the BSs 110 and 160 and the MSs 111, 113, 130, 151, and 153 are performed using the OFDM / OFDMA scheme.

Meanwhile, when transmitting a signal, an unavoidable error occurs due to noise, interference, fading, etc., depending on a channel condition, resulting in loss of information. In general, various methods are used to prevent the loss of such information. One of the typical methods used to prevent data loss or loss is ARQ. The ARQ scheme refers to a technique for notifying the transmitter of a specific data transmitted by the transmitter or not transmitting the data to the transmitter and transmitting the same again. Next, the ARQ scheme will be described in the IEEE 802.16d and IEEE 802.16e systems.

First, referring to the matter disclosed in the IEEE 802.16 system, the transmitter will be referred to as a medium access control (MAC) service data unit (SDU). ) Is divided into ARQ block units and transmitted to the receiver. Then, the receiver informs the transmitter whether to receive each individual ARQ block. At this time, both the transmitter and the receiver should be able to distinguish each block transmitted. This is because it is possible to know which blocks have been received and which blocks require ARQ only if each block can be distinguished. As described above, in order to distinguish each block, the transmitter and the receiver use a block sequence number (BSN) to distinguish each block from each transmitted block. .

In addition, the ARQ method is a ACK (ACK: ACKnowledment, hereinafter referred to as 'ACK') / non-receipt (NACK: ACK) for the signal transmitted by the transmitter itself from the receiver When receiving a feedback message and receiving a NACK message from the receiver, the message is retransmitted to increase reliability of signal transmission. Here, the receiver feeds back the ACK message to the transmitter when the signal transmitted from the transmitter is normally received, and when the signal is abnormally received by the transmitter, that is, an error ( error), the NACK message is fed back to the transmitter. In addition, a unit of a signal transmitted by a transmitter in a communication system to which the ARQ scheme is applied is an ARQ encoder packet (hereinafter referred to as an 'Aep'), and one Aep is one or more MAC protocol data units ( PDU: Protocol Data Units (hereinafter referred to as PDUs) are concatenated, and a CRC (Cyclic Redundancy Check) code is inserted into the concatenated MAC-PDUs. Here, the PDU is a transmission unit for transmitting data to a transmitter, that is, a BS to a receiver, that is, an MS, and a transmission unit in an upper layer of the PDU is an SDU.

As described above, the receiver may randomly and abnormally receive the received PDU divided into block units. A NACK message corresponding to random abnormal reception of the PDU, that is, a NACK message including abnormal reception information of the PDU is transmitted to the transmitter. In this case, as the number of PDUs abnormally received from the transmitter increases, the amount of abnormal reception information of the PDU included in the NACK message increases. However, since the information that the receiver can include in the NACK message is limited, the efficiency of ACK decreases as the amount of abnormally received information of the PDU increases, and the PDU that the transmitter needs to retransmit to the receiver increases. Therefore, there is a problem that the performance of the system is degraded.

Accordingly, an object of the present invention is to provide a data transmission method and system in a communication system.

Another object of the present invention is to provide a data transmission method and system in a communication system employing an automatic repeat request method.

In accordance with another aspect of the present invention, a method for transmitting data in a communication system includes receiving a plurality of data blocks from a transmitter, checking a reception state of the received data blocks, and checking the reception state. As a result, data blocks of the same reception state are sequentially grouped into sequence blocks, the number of data blocks included in the grouped sequence blocks and thresholds are compared, and the group blocks are received according to the comparison result. Sending status information to the transmitter.

Another method of the present invention for achieving the above object is, in a data transmission method in a communication system, when receiving a plurality of data blocks from a transmitter, checking the reception status of the received data blocks, the check of the reception status As a result, the data blocks successively received are grouped into first sequence blocks, and the abnormally received data blocks are continuously grouped into second sequence blocks as a result of the check of the reception state, and included in the grouped sequence blocks. And comparing the number of data blocks with thresholds, and transmitting the received state information of the grouped sequence blocks to the transmitter according to the comparison result.

The system of the present invention for achieving the above object, in the data transmission system in the communication system, when receiving a plurality of data blocks from the transmitter, checks the reception status of the received data blocks, and the check result of the reception status Group the normally received data blocks consecutively into first sequence blocks, group the abnormally received data blocks into second sequence blocks as a result of the check of the reception state, and include the data included in the grouped sequence blocks And a receiver for comparing the number of blocks with thresholds and transmitting the received state information of the grouped sequence blocks to the transmitter according to the comparison result.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

The present invention proposes a data transmission method and system in a communication system. Here, in the embodiment of the present invention to be described later, orthogonal in the Institute of Electrical and Electronics Engineers (IEEE) 802.16d / e communication system which is a broadband wireless access (BWA) communication system (hereinafter referred to as "BWA") A communication system employing Orthogonal Frequency Division Multiplexing (OFDM) / Orthogonal Frequency Division Multiple Access (OFDMA) scheme As an example, the data transmission method proposed by the present invention may be applied to other communication systems. In addition, the present invention proposes a data transmission method and system in a communication system for preventing the loss of information when an inevitable error occurs due to noise, interference, fading, etc. according to the channel condition. do. In the embodiment of the present invention to be described later, a data transmission method in a communication system to apply an automatic repeat request (ARQ: Automatic Repeat ReQuest, ARQ) method as a method for preventing the loss of the above-described information and Suggest a system.

In addition, the present invention is a transmitter, such as a base station (BS) (hereinafter referred to as "BS") that provides a communication service in a communication system applying the ARQ scheme is a receiver, for example a mobile terminal (MS) MS and a method and system for transmitting data to the MS). In this case, the ARQ method is a method for preventing the loss of information when an error occurs due to noise, interference, fading, etc. according to channel conditions, and thus, loss of information. If the receiver does not receive the data or the decoding is not successful, it is notified to the transmitter so that the transmitter can transmit it again.

In an embodiment of the present invention to be described later, a medium access control (MAC) service data unit (SDU), in which a transmitter of a communication system to which the ARQ scheme is applied is transmitted from an upper layer, is transmitted from an upper layer. Service Data Unit, hereinafter referred to as 'SDU') is divided into ARQ block units and transmitted to the receiver. Then, the receiver sends a receipt (ACK: ACKnowledment, hereinafter 'ACK') / non-receipt (NACK: Non-ACKnowledment, hereinafter 'NACK') message for the signal transmitted by the transmitter to the transmitter When feedbacking, the transmitter retransmits the transmitted signal when receiving a NACK message from the receiver to increase the reliability of signal transmission. In this case, the receiver feeds back the ACK message to the transmitter when the signal transmitted from the transmitter is normally received, and when the signal is abnormally received from the transmitter, that is, an error in the signal transmitted from the transmitter. When an error occurs, the NACK message is fed back to the transmitter. Next, a data transmission scheme in a communication system to which the ARQ scheme according to the embodiment of the present invention is applied will be described with reference to FIGS. 2A and 2B.

2A and 2B schematically illustrate transmission and reception data in a communication system to which the ARQ scheme is applied according to an embodiment of the present invention. Here, FIG. 2A illustrates a signal transmitted from a higher layer to a receiver by the transmitter in an ARQ block unit in the communication system, that is, a transmission unit in a lower layer of the SDU corresponding to an SDU and a scheduling scheme of the transmitter. That is, a diagram illustrating a MAC protocol data unit (hereinafter referred to as a PDU). 2B is a diagram illustrating a reception state of the PDU of the receiver receiving the signal transmitted from the transmitter, that is, the aforementioned PDU in the communication system.

Referring to FIG. 2A, a transmitter divides an SDU 210 transmitted from an upper layer in units of ARQ blocks and distinguishes each of the divided ARQ blocks by a block sequence number (BSN). To be called). That is, when the transmitter divides the SDU into ARQ block units and transmits the SDUs to the receiver, the receiver should inform the transmitter whether to receive the individual ARQ blocks. Therefore, the transmitter and the receiver should be able to distinguish each ARQ block transmitted. This is because it is possible to know which ARQ blocks have been normally received only when each ARQ block can be distinguished, and which ARQ blocks are abnormally received so as to know whether to request ARQ for the abnormally received ARQ blocks.

As described above, in order to distinguish each ARQ block by the transmitter and the receiver, the transmitter uses a BSN in each ARQ block to distinguish each ARQ block transmitted to the receiver. Accordingly, the transmitter defines BSNs, i.e., '5,6,7,8,9,10,11,12,13,14' in each ARQ blocks of the SDU 210, and the transmitter, e. Corresponding to the scheduling scheme, each ARQ block divides the SDU 210 defined as BSNs into a plurality of PDUs, that is, PDU1 250 and PDU2 270. Here, the transmitter has been described as only splitting one SDU 210 into two PDUs 250 and 270 according to a scheduling scheme. Multiple SDUs may be packed into one PDU. The SDU 210 delivered from the upper layer is divided into PDUs 250 and 270 which are data transmission units in the lower layer and transmitted to the receiver. Assume that the receiver receives the PDUs 250 and 270 transmitted from the transmitter as shown in FIG. 2B.

Referring to FIG. 2B, the receiver receives a PDU in which each ARQ block is defined as BSNs from a transmitter. Here, in FIG. 2A, each ARQ block BSNs of a PDU transmitted by a transmitter are defined as '5, 6, 7, 8, 9, 10, 11, 12, 13, and 14'. In FIG. 2B, more PDUs than PDUs transmitted by the transmitter, that is, each ARQ block BSN is represented by '5,6,7,8,9,10,11,12,13,14,15,16,17,18, Assume that a PDU defined as 19, 20, 21, 22, 23, 24, 25, 26, 27, 28 'is received from a transmitter. That is, FIG. 2B shows that a transmitter transmits a PDU in which BSNs of each ARQ block are defined as '5 to 28', and from the transmitter, a receiver receives a PDU in which each ARQ block BSNs are defined as '5 to 28'. have.

As shown in FIG. 2B, ARQ blocks abnormally received from a transmitter have an '×' indication, that is, BSN is' 7,8,10,11,12,19,20,21,22,23,24,25. ARQ blocks defined as' are ARQ blocks abnormally received by the receiver. The receiver feeds back an ACK / NACK message for the ARQ blocks of the PDU from the transmitter to the transmitter. Next, a method of constructing an ACK / NACK message for ARQ blocks received from a transmitter by the receiver in a communication system applying the ARQ scheme according to an embodiment of the present invention will be described in detail. .

In the method for configuring an ACK / NACK message for ARQ blocks received in a communication system employing an ARQ scheme according to an embodiment of the present invention, an ACK-MAP is defined with a predetermined size defined for transmitting the ACK / NACK message. ACK / NACK information for each ARQ block is included and transmitted. The method of transmitting the ACK / NACK message may include a selective ACK / NACK method, a cumulative ACK / NACK method, a cumulative cumulative ACK / NACK method, Cumulative with Block Sequence ACK / NACK (Cumulative with Block Sequence ACK / NACK) method and Enhanced Cumulative with Block Sequence ACK / NACK (Enhanced Cumulative with Block Sequence ACK / NACK) method. And an ACK-MAP and a sequence length (hereinafter referred to as 'SL') to the transmitter.

First, in the selective ACK / NACK method, ARQ blocks normally received among ARQ blocks received by the receiver, that is, BSN is' 5, 6, 9, 13, 14, 156, 16, 17, 18, 26, 27 Selectively display only ARQ blocks defined as '28', for example, display only the normally received ARQ blocks as '1' to configure an ACK / NACK message, and transmit the ACK / NACK message to the transmitter. In more detail, when the receiver receives the ARQ blocks as shown in FIG. 2B, the receiver uses the selective ACK / NACK method in response to the received ARQ blocks to perform the following BSN and ACK- Send the MAP to the transmitter.

→ BSN: 5, ACK-MAP: 0b1100100011111100

Here, since the receiver has received the PDU from the ARQ block in which the BSN is defined as '5', the BSN becomes '5', and since the ACK-MAP is represented in binary, the start bit of the ACK-MAP becomes '0b'. The bit corresponding to the ARQ block normally received in the ACK-MAP is represented by '1', and the bit corresponding to the abnormally received ARQ block is represented by '0'. In this case, since the size of the ACK-MAP that the receiver can transmit to the transmitter is 16 bits, the receiver uses the above-described selective ACK / NACK method to transmit the BSN among the ARQ blocks received from the transmitter as shown in FIG. 2B. ARQ blocks defined as '5 to 20' and reception status information of 16 ARQ blocks, that is, ACK / NACK information, may be transmitted to the transmitter.

Next, the cumulative ACK / NACK method, as shown in FIG. 2b can be represented as a method of displaying the BSN of the ARQ block continuously received from the normal received blocks of the ARQ blocks received.

→ BSN: 6

That is, when the receiver receives the ARQ blocks from the transmitter as shown in FIG. 2B, the receiver continuously receives the ARQ blocks in which the BSN is defined as '5, 6' and the ARQ blocks in which the BSN is defined as '7'. Is received abnormally, using the cumulative ACK / NACK method, the information indicating the BSN as described above, that is, reception status information for indicating that there is an abnormally received ARQ block after the ARQ block defined by the BSN '6', ACK / NACK information may be transmitted to the transmitter.

The selective cumulative ACK / NACK method is a method of using a combination of the above-described selective ACK / NACK method and the cumulative ACK / NACK method, and the cumulative ACK / NACK method for the normal received ARQ block before the abnormally received ARQ block. The NACK method is applied and the selective ACK / NACK method is applied to the ARQ block after the cumulative ACK / NACK method is applied. In more detail, when the receiver receives the ARQ blocks as shown in FIG. 2B, the receiver uses the selective cumulative ACK / NACK method in response to the received ARQ blocks. -Send the MAP to the transmitter.

→ BSN: 6, ACK-MAP: 0b1001000111111000

Here, since the receiver normally receives the ARQ block in which the BSN is defined as '5,6', the BSN becomes '6', and since the BSN abnormally receives the ARQ block in which the BSN is defined as '7', the ACK-MAP is normally received. ARQ blocks defined as one block, that is, the BSN is defined as '6,9,13,14,15,16,17,18' are marked as '1', and the non-calculated block, that is, the BSN is defined as '7,8' ARQ blocks defined as '10, 11, 12, 19, 20, and 21 'are represented by' 0 '. In addition, since the ACK-MAP is represented by a binary number, the start bit of the ACK-MAP becomes '0b'. In this case, since the size of the ACK-MAP that the receiver can transmit to the transmitter is 16 bits, the receiver receives ARQ blocks received from the transmitter as shown in FIG. 2B using the selective cumulative ACK / NACK method described above. Among them, ARQ blocks in which BSNs are defined as '5 to 21', that is, reception status information of 17 ARQ blocks, that is, ACK / NACK information, may be transmitted to a transmitter.

In addition, the block sequence cumulative ACK / NACK method expresses the above-described cumulative ACK / NACK method, the ARQ block which is normally received continuously, and the ARQ block which is abnormally received continuously, as one block sequence to express a small bit of ACK-MAP length. By using this method, the reception status information of many ARQ blocks is transmitted. In more detail, when the receiver receives the ARQ blocks as shown in FIG. 2B, the receiver uses the block sequence cumulative ACK / NACK method in response to the received ARQ blocks and Send ACK-MAP, and SL to the transmitter.

→ BSN: 6, ACK-MAP: 0b010

→ SL1: 2, SL2: 1, SL3: 3

Here, since the receiver normally receives the ARQ block in which the BSN is defined as '5,6', the BSN becomes '6' and the ARQ block in which the BSN is defined as '7,8' becomes the block sequence '1'. In addition, the ARQ block in which the BSN is defined as' 9 'is not an ARQ block normally received, but the block sequence is' 2', and the ARQ block in which the abnormally received BSN is defined as '10, 11, 12 'is The block sequence is '3'. Then, a block sequence including a normally received ARQ block for each block sequence is represented by '1', and a block sequence including an abnormally received ARQ block is represented by '0'. In addition, since the ACK-MAP is represented by a binary number, the start bit of the ACK-MAP becomes '0b'. The SL represents the number of ARQ blocks including each block sequence. Accordingly, SL1 is '2', SL2 is '1', and SL3 is '3'. In this case, since there are up to three block sequences, the receiver uses the block sequence cumulative ACK / NACK method, and an ARQ block having BSNs defined as '5 to 12' among ARQ blocks received from the transmitter as shown in FIG. 2B. For example, reception state information of eight ARQ blocks, that is, ACK / NACK information, may be transmitted to a transmitter.

The improved block sequence cumulative ACK / NACK method is a method to which the aforementioned block sequence cumulative ACK / NACK method is applied, and indicates the number of abnormally received abnormal ARQ blocks or consecutively received normal ARQ blocks. Compare with the user-set thresholds corresponding to the performance of. In this case, when the number of normal ARQ blocks existing between successively received abnormal ARQ blocks is smaller than a threshold value, the enhanced block sequence cumulative ACK / NACK method detects normal ARQ blocks smaller than the threshold value. It may be regarded as an abnormal ARQ block and may transmit reception state information and ACK / NACK information of a plurality of ARQ blocks to a transmitter with bits of limited ACK-MAP.

More specifically, when the receiver receives ARQ blocks as shown in FIG. 2B, the block sequence cumulative ACK / NACK method has a BSN of '6' and a ACK-MAP of '0b010' as described above. Sequence block 1 includes ARQ blocks in which the BSN is defined as '7, 8', sequence block 2 includes an ARQ block in which the BSN is defined as '9', and sequence block 3 is defined as '10, 11, It contains ARQ blocks defined as 12 '. SL1, which is the length of each block sequence, is '2', SL2 is '1', and SL3 is '3'. In this case, in the block sequence cumulative ACK / NACK method, the sequence block 2 is occupied by one ARQ block in which the BSN is defined as '9', thereby reducing the efficiency of transmitting ACK / NACK information to the transmitter.

On the other hand, in the improved block sequence cumulative ACK / NACK method, a plurality of abnormally received ARQ blocks, for example, BSNs, are present between a plurality of abnormal ARQ blocks defined as '7,8,10,11,12'. Since the normal ARQ block in which the BSN is defined as '9' is smaller than the first threshold set to '1', the normal ARQ block in which the BSN is defined as '9' is regarded as an abnormal block. That is, in the enhanced block sequence cumulative ACK / NACK method, the number of consecutively received abnormal ARQ blocks including the normal ARQ smaller than the first threshold value and the number of successive normal ARQ blocks smaller than the first threshold value are shown. If is greater than the second threshold value, the number of normal ARQ blocks smaller than the first threshold value present between the consecutively received abnormal ARQ blocks larger than the second threshold value is regarded as an abnormal block. For example, when the receiver receives the ARQ blocks as shown in FIG. 2B, when the first threshold value is set to '1' and the second threshold value is set to '5', the receiver is improved. In response to the ARQ blocks received using the block sequence ACK / NACK method, BSN, ACK-MAP, and SL as described below are transmitted to the transmitter.

→ BSN: 6, ACK-MAP: 0b010

→ SL1: 6, SL2: 6, SL3: 7

Here, since the receiver normally receives the ARQ block in which the BSN is defined as '5,6', the BSN becomes '6' and the ARQ block in which the BSN is defined as '7,8,9,10,11,12' The block sequence is '1'. In addition, an ARQ block in which the BSN is defined as '13, 14,15,16,17,18 'becomes a block sequence' 2 ', and the BSN is defined as '19, 20,21,22,23,24,25'. ARQ block becomes the block sequence '3'. Then, the block sequence including the normally received ARQ block for each block sequence is denoted by '1', and the block sequence including the abnormally received ARQ block is denoted by '0'. In addition, since the ACK-MAP is represented by a binary number, the start bit of the ACK-MAP becomes '0b'. The SL represents the number of ARQ blocks including each block sequence. That is, SL1 is '6', SL2 is '6', and SL3 is '7'. In this case, since there are up to three block sequences, the receiver uses the block sequence cumulative ACK / NACK method, and the ARQ blocks having BSNs defined as '5 to 25' among ARQ blocks received from the transmitter as shown in FIG. 2B. For example, reception state information of 21 ARQ blocks, that is, ACK / NACK information, may be transmitted to the transmitter.

3 is a diagram illustrating an ARQ operation process between a transceiver in a communication system according to an embodiment of the present invention. First, prior to the description of FIG. 3, the following description will be given to the operation in the MAC layer between the transceiver.

Referring to FIG. 3, first, when the SDU data arrives from the higher layer (step 311), the transmitter 301 drives a timer (step 313). At this time, the timer is a timer for detecting the occurrence of ARQ_SYNC_LOSS_TIMEOUT. After driving the timer as described above, the transmitter 301 transmits the MAC PDU received from the upper layer to the receiver 303 (step 315). The receiver 303 then receives the MAC PDU transmitted from the transmitter 301, drives a timer to detect the occurrence of ARQ_SYNC_LOSS_TIMEOUT, and then decodes the received MAC PDU (step 317). Then, the receiver 303 transmits the result of decoding the MAC PDU to the transmitter 301. 3 illustrates an example in which the receiver 303 fails to decode, that is, an abnormally received PDU from the transmitter 301.

If the receiver 303 fails to decode the MAC PDU received from the transmitter 301, the receiver 303 constructs a NACK message requesting retransmission and transmits it to the transmitter 301 (step 319). In this case, since the method for configuring and transmitting the NACK message transmitted by the receiver 303 has been described above in detail, a detailed description thereof will be omitted. When the transmitter 301 receives the NACK message from the receiver 303, the transmitter 301 generates the same data as the MAC PDU and transmits the same to the NACK message in step 315 and transmits it again (step 321). In this case, the transmitted data may be data composed of the same bits, or may transmit redundancy of the initially transmitted information to assist in decoding the initially transmitted data.

Next, when receiving the MAC PDU data retransmitted from the transmitter 301, the receiver 303 decodes the received MAC PDU data again (step 323). Thereafter, the receiver 303 transmits the decoding result of the received MAC PDU data to the transmitter 301 (step 325). In FIG. 3, it is assumed that in the second reception, the MAC PDU is normally received and the decoding is successful. Accordingly, the receiver 303 transmits ACK information corresponding to the decoding success to the transmitter 301 in step 325. In addition, after transmitting the ACK information as described above, the receiver 303 proceeds to step and delivers the MAC PDU to the upper stage (step 327).

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention can increase data transmission efficiency, data transmission reliability, and system performance by increasing the number of acknowledgment blocks that can be transmitted using a limited bitmap in a communication system to which an automatic repeat request scheme is applied. have.

Claims (12)

In a data transmission method in a communication system, When receiving a plurality of data blocks from the transmitter, check the reception status of the received data blocks, Grouping data blocks of the same reception state into sequence blocks as a result of the check of the reception state; Compare the number of data blocks included in the grouped sequence blocks and threshold values, And transmitting the reception status information of the grouped sequence blocks to the transmitter according to the comparison result. The method of claim 1, According to the comparison result, the receiving state information of the grouped sequence blocks is transmitted to the transmitter. The number of data blocks included in any first sequence block among the grouped sequence blocks is greater than the first threshold value. If the number of data blocks included in the second sequence block in a different reception state adjacent to the first sequence block is larger than a second threshold value, the data sequence included in the first sequence block is included in the second sequence block. Characterized in that the data transmission method. The method of claim 2, The data block included in the first sequence block is a data block normally received, and the data block included in the second sequence block is an abnormally received data block. The method of claim 1, And transmitting the reception state information of the grouped sequence block to the transmitter, transmitting the number of data blocks included in the sequence block to the transmitter. In a data transmission method in a communication system, When receiving a plurality of data blocks from the transmitter, check the reception status of the received data blocks, Grouping normally received data blocks into first sequence blocks as a result of the check of the reception state, grouping abnormally received data blocks into second sequence blocks, Compare the number of data blocks included in the grouped sequence blocks and threshold values, And transmitting the reception status information of the grouped sequence blocks to the transmitter according to the comparison result. The method of claim 5, In the transmitting of the received state information of the grouped sequence blocks to the transmitter according to the comparison result, the number of data blocks included in the grouped first sequence blocks is smaller than a first threshold value, and the first sequence value. And if the number of data blocks included in the second sequence block adjacent to the block is greater than the second threshold, including the data blocks included in the first sequence block in the second sequence block. The method of claim 5, Transmitting the received state information of the grouped sequence block to the transmitter, transmitting the sequence number of the immediately received data block immediately before the first received abnormal data block among the abnormally received data blocks to the transmitter. A data transmission method characterized by the above-mentioned. The method of claim 5, And transmitting the reception state information of the grouped sequence block to the transmitter, transmitting the number of data blocks included in the sequence block to the transmitter. In a data transmission system in a communication system, When receiving a plurality of data blocks from a transmitter, the reception state of the received data blocks is checked, and as a result of the check of the reception state, the normally received data blocks are grouped into first sequence blocks and abnormally received data blocks are received. Are grouped into second sequence blocks, the number of data blocks included in the grouped sequence blocks and thresholds are compared, and the reception state information of the grouped sequence blocks is transmitted to the transmitter according to the comparison result. A data transmission system comprising a receiver. The method of claim 9, The receiver may include a number of data blocks included in the grouped first sequence blocks less than a first threshold value, and a number of data blocks included in a second sequence block adjacent to the first sequence block than a second threshold value. If larger, the data transmission system including the data block included in the first sequence block in the second sequence block to transmit the reception state information of the grouped sequence blocks to the transmitter. The method of claim 9, And the receiver transmits the sequence number of the immediately received data block immediately before the first received abnormal data block among the abnormally received data blocks to the transmitter. The method of claim 9, The receiver transmits the number of data blocks included in the sequence block to the transmitter.

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