KR101201898B1 - Apparatus and method for arq feedback message generating in wireless communication system - Google Patents

Abstract

The present invention relates to an apparatus and method for generating an Automatic Repeat Request (ARQ) feedback message in a wireless communication system. A method for ARQ feedback at a receiving end according to the present invention includes receiving a plurality of ARQ blocks and transmitting an ARQ feedback message including first information, second information and third information to an ARQ block transmitting end. Wherein the first information indicates any one of an ACK block and a NACK block of a received ARQ block, and the second information indicates that the NACK block is any one of a full NACK block and a partial NACK block, The third information indicates whether reception of at least one ARQ subblock among ARQ subblocks for the partial NACK block is successful.

Wireless Communication System, ARQ (Automatic Repeat ReQuest), ARQ Block, ARQ Sub-Block, ARQ Feedback, Cumulative ACK, Selective ACK

Description

Apparatus and method for generating automatic retransmission request feedback message in wireless communication system {APPARATUS AND METHOD FOR ARQ FEEDBACK MESSAGE GENERATING IN WIRELESS COMMUNICATION SYSTEM}

The present invention relates to an apparatus and a method for Automatic Repeat ReQuest (ARQ) in a wireless communication system, and more particularly, to an apparatus and a method for generating an ARQ feedback message in a wireless communication system.

In a wireless communication system, an error may occur in data according to a channel state of a radio resource for transmitting data. Accordingly, the wireless communication system controls and recovers data errors by using an ARQ technique to increase transmission reliability.

In the case of using the ARQ scheme, the receiving end informs the transmitting end whether the ARQ block received from the transmitting end is successful. For example, when no error occurs in the ARQ block received from the transmitting end, the receiving end transmits ACK information to the transmitting end. On the other hand, if an error occurs in the ARQ block received from the transmitting end, the receiving end transmits NACK information to the transmitting end. Here, a series of operations in which the receiving end transmits a successful reception of the received ARQ block to the transmitting end is called ARQ feedback.

The receiving end may perform ARQ feedback using a cumulative ACK method and a selective ACK method. When using the cumulative ACK scheme, the receiving end transmits a sequence number of the last ARQ block among successive ARQ blocks to the transmitting end. In the case of using the selective ACK scheme, the receiving end constructs a bitmap indicating whether reception of the ARQ block provided from the transmitting end is successful and transmits the bitmap.

When the ARQ block is configured with a variable length, the transmitting end may divide the ARQ block into a plurality of ARQ subblocks and retransmit the same to the receiving end. In this case, the receiving end should transmit the ARQ feedback information for the ARQ block and the ARQ feedback information for the ARQ lower block to the transmitting end. That is, a problem arises in that an amount of resources for transmitting ARQ feedback information increases at the receiving end.

Accordingly, when the transmitting end configures the ARQ block to have a variable length, there is a need for a method for efficiently transmitting ARQ feedback information for the ARQ block and the ARQ sub-block in the reception die.

Accordingly, an object of the present invention is to provide an apparatus and method for generating an ARQ feedback message at a receiving end of a wireless communication system.

Another object of the present invention is to provide an apparatus and method for generating an ARQ feedback message using a cumulative ACK scheme and a selective ACK scheme at a receiving end of a wireless communication system.

Another object of the present invention is to provide an apparatus and method for generating an ARQ feedback message for an ARQ subblock in a wireless communication system.

Another object of the present invention is to provide an apparatus and a method for reducing overhead of an ARQ feedback message for an ARQ lower block in a receiving end of a wireless communication system.

Another object of the present invention is to provide an apparatus and method for generating an ARQ feedback message including ARQ feedback information of an ARQ block and an ARQ sub-block in a receiving end of a wireless communication system.

It is still another object of the present invention to provide an apparatus and method for adding ARQ feedback information of an ARQ subblock to ARQ feedback information of an ARQ block using an ExT field and an SEM field in a receiving end of a wireless communication system.

According to a first aspect of the present invention for achieving the objects of the present invention, a method for transmitting an automatic retransmission request (ARQ) feedback message in the ARQ block receiving end of the wireless communication system, the process of receiving a plurality of ARQ blocks; And transmitting an ARQ feedback message including first information, second information, and third information to an ARQ block transmitting end, wherein the first information includes any one of an ACK block and a NACK block of the received ARQ block. The second information indicates that the NACK block is any one of a total NACK block and a partial NACK block, and the third information indicates that at least one ARQ subblock of an ARQ subblock for the partial NACK block is represented. Indicates whether the reception was successful.

According to a second aspect of the present invention, an ARQ block receiving apparatus of a wireless communication system includes: a receiver for receiving a plurality of ARQ blocks; and ARQ block transmission of ARQ feedback information including first information, second information, and third information. Wherein the first information indicates any one of an ACK block and a NACK block of an ARQ block, and the second information indicates that the NACK block is any one of a full NACK block and a partial NACK block. The third information indicates whether reception of at least one ARQ subblock among ARQ subblocks for the partial NACK block is successful.

As described above, by generating the ARQ feedback message by adding the feedback information of the ARQ sub-block to the feedback information of the ARQ block at the receiving end of the wireless communication system, ARQ feedback can be performed for the ARQ block and the ARQ sub-block. Can reduce the overhead.

In addition, by checking the feedback information of the ARQ block and the ARQ lower block in one ARQ feedback message provided from the receiving end, the transmitting end may reduce a delay time for checking the feedback information for the ARQ lower block.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that a detailed description of related known functions or generations may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

Hereinafter, a description will be given of a technique for generating an Automatic Repeat reQuest (ARQ) feedback message at a receiving end of a wireless communication system.

In the following description, the transmitting end and the receiving end include all transmitting and receiving nodes constituting a wireless communication system such as a base station controller, a base station, a terminal, and a relay station.

ARQ operation occurs at the Media Access Control (MAC) layer. Accordingly, the transmitting end generates an ARQ block or an ARQ block for retransmission at the MAC layer as shown in FIG. 1 for ARQ.

1 illustrates a configuration of an ARQ block in a wireless communication system according to an embodiment of the present invention.

Referring to FIG. 1, (a) of FIG. 1 shows a configuration of an ARQ block for data transmission, and (b) of FIG. 1 shows a configuration of an ARQ subblock for retransmission, and (c) of FIG. ) Denotes a configuration of an ARQ block for retransmission.

As shown in (a) of FIG. 1, a transmitting end is a transmission unit of a MAC layer by dividing a service data unit (SDU) or a plurality of service data units transmitted from an upper layer to a MAC layer. Configure the MPDU (MAC Protocol Data Unit).

When ARQ is applied to an MPDU, the transmitting end allocates an ARQ block sequence number (ARQ SN) in units of MPDUs. That is, the transmitting end configures one MPDU as one ARQ block. For example, when transmitting two service data units in the upper layer to the MAC layer, the transmitting end configures three MPDUs using the two service data units. In this case, the transmitting end allocates an ARQ block sequence number from 1 to 3 to each MPDU. Here, the transmitting end adds control information such as an ARQ block sequence number to the MPDU in the form of a MAC header.

If an error occurs in ARQ block 2 of the ARQ blocks transmitted by the transmitting end, the receiving end requests retransmission for the ARQ block 2 through the ARQ feedback.

The transmitter may retransmit the error-prone ARQ block into a plurality of ARQ subblocks. For example, as shown in (b) of FIG. 1, the transmitting end divides the ARQ block 2 in which the error occurs into seven ARQ subblocks. Thereafter, the transmitting end configures an MPDU including three ARQ subblocks and an MPDU including four ARQ subblocks and transmits the MPDU to the receiving end. At this time, the transmitting end allocates an ARQ subblock sequence number (ARQ SUB SN) to each ARQ subblock.

Also, the transmitting end may retransmit the original ARQ block for the ARQ block in which the error occurs to the receiving end. For example, as illustrated in (c) of FIG. 1, the transmitting end retransmits an original ARQ block for an ARQ block in which an error occurs to the receiving end. At this time, the transmitting end retransmits the MPDU for the ARQ block 2 including the ARQ block sequence number to the receiving end.

When the receiving end retransmits the ARQ block or the ARQ subblock, the receiving end uses the ARQ block sequence number of the ARQ block or the ARQ subblock sequence number of the ARQ subblock, or the ARQ feedback for the ARQ block or ARQ subblock that has been retransmitted. Generate information.

As described above, the transmitting end transmits an ARQ block or an ARQ subblock to the receiving end. At this time, the receiving end transmits the ARQ feedback message generated by using the cumulative ACK method and the selective ACK method as shown in FIG. 2 to the transmitting end.

2 illustrates a configuration of an ARQ feedback message in a wireless communication system according to an embodiment of the present invention.

As shown in (a) of FIG. 2, it is assumed that the receiving end receives ARQ blocks 3 to 9 from the transmitting end. In this case, it is assumed that an error occurs in ARQ blocks 3, 5, 6 and 8 among the ARQ blocks received by the receiving end.

As described above, when an error occurs in the ARQ block, the receiving end generates ARQ feedback information for seven ARQ blocks through the selection ACK map as shown in FIG. For example, when the selection ACK map consists of 7 bits, the receiving end configures the selection ACK map such as '0100101'. In this case, the receiving end may configure the ARQ feedback information to include the sequence number of the ARQ block No. 3 where an error occurs first.

There may be an ARQ block composed of at least one ARQ subblock among ARQ blocks indicated as having an error through the selection ACK map. If there is an ARQ block composed of at least one ARQ subblock among the ARQ blocks in which an error occurs, and there is an ARQ subblock in which the receiving end has successfully received among the ARQ subblocks constituting the ARQ block, the receiving end Needs additional information to inform the transmitting end whether an error for the ARQ lower block has occurred. In addition, the receiving end needs control information to indicate the presence of the additional information. For example, the receiving end indicates that information to be added to the ARQ feedback information exists using 'ExT'. If the additional information is present, the receiving end sets 'ExT' to 1. Accordingly, when 'ExT' is 1, the transmitting end recognizes that there is an ARQ lower block that is successfully received in the ARQ block in which an error occurs. On the other hand, if the additional information does not exist, the receiving end sets 'ExT' to zero. Accordingly, when 'ExT' is 0, the transmitting end recognizes that there is no ARQ lower block which is successfully received in the ARQ block in which an error occurs.

Among the ARQ blocks in which the error occurs, ARQ block 3 and ARQ block 6 are composed of at least one ARQ subblock, and among the ARQ subblocks of ARQ block 3 and 6, the successfully received ARQ subblock exists. If so, the receiving end should transmit ARQ feedback information for the ARQ lower block to the transmitting end. In this case, the receiving end indicates an ARQ block representing ACK / NACK information of the ARQ subblock using 'SEM (Sub-block Existence MAP)' as shown in FIG. For example, the receiving end configures the SEM in 4 bits so as to indicate an ARQ block representing the ACK / NACK information of the ARQ lower block among the ARQ blocks in which an error occurs. In this case, the receiving end displays the bits of the SEMs representing ARQ blocks 3 and 6 composed of ARQ subblocks as '1', and the SEMs representing ARQ blocks 5 and 8 not configured as ARQ subblocks. Bit of '0' is displayed. If an error occurs in all ARQ sub-blocks constituting the ARQ block, the receiving end marks the bit of the SEM representing the corresponding ARQ block as '0'. That is, the receiving end displays a bit of the SEM indicating the ARQ block including the ARQ lower block which has been successfully received among the ARQ blocks in which an error occurs, as '1'. In this case, the receiving end indicates whether the 'SEM' is present using 'ExT'.

In addition, the receiving end additionally configures ACK / NACK information for the ARQ lower block for the ARQ block indicated by '1' in the SEM and transmits it to the transmitting end. For example, the receiving end successfully receives ARQ subblocks 3-1 to 3-4 constituting ARQ block 3, and errors in ARQ subblocks 3-5 through 3-7. Assume that has occurred. In this case, the receiving end may display the selection ACK map for the ARQ lower block as '1111000' as shown in FIG. For another example, the receiving end successfully receives ARQ subblocks 6-1, 6-2, 6-6, and 6-7 constituting ARQ block 6, 6-3, and 6-4. Assume that an error has occurred in ARQ subblocks 1 through 6-5. In this case, the receiving end may display the selection ACK map for the ARQ lower blocks as '1100011', as shown in (e) of FIG. 2.

The receiving end may add the ARQ feedback information of the ARQ lower block to the ARQ feedback information of the ARQ block using the ExT field and the SEM field as shown in Table 1 below. In this case, it is assumed that the receiving end configures ARQ feedback information for the ARQ block and the ARQ lower block by using the cumulative ACK method and the selective ACK method. Here, the receiving end generates ARQ feedback information in the form of an information element (IE).

Syntax Size (bit) Notes ARQ_feedback_IE (LAST) { variable  Last One 0 = More ARQ Feedback IE in the list
1 = Last ARQ Feedback IE in the list  Flow ID 4 The ID of the connection (flow) being referenced  FLAG1 One 0 = Cumulative ACK
1 = Selective ACK MAP existence  SN 10 FLAG = 0, ARQ block up to and including SN has been received successfully.
FLAG = 1, ARQ block less than SN has been received successfully.  if (FLAG1 == 1) {   Selective ACK MAP 1 6 Each bit represents ACK or NAK of corresponding ARQ block. '0' is NAK and '1' is ACK.
First MSB of first Selective ACK MAP1 represents ACK or NAK information of SN. Contiguous bits after first MSB of first ACK MAP are corresponding to contiguous SN.   ExT One Extension for ARQ sub-block indication
0 = No ARQ sub-block ACK / NACK indication
1 = ARQ sub-block ACK / NACK indication follows   FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and FLAG1 follow   while (FLAG1 == 1) {    Selective ACK MAP1 7 Each bit represents ACK or NAK of corresponding ARQ block. '0' is NAK and '1' is ACK.
Selective ACK MAP1 represents ACK or NAK information of ARQ blocks after first selective ACK MAP1.    FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and FLAG1 follow   }   if (Ext == 1) {    SEM variable Sub-block-Existence bitMap

The numbers of SEM bits are same as NACKed ARQ block in the Selective ACK MAP1.Each bit represents the existence of partially nacked ARQ blocks or completely nacked ARQ blocks.

1 = Partially nacked ARQ block (the ARQ block has some sub-blocks which have received correctly)
0 = Completely nacked ARQ blocks (the ARQ block has no sub-blocks which have received correctly)    for (i = 0; i <Num_block <i ++) { Num_block is the number of bits equal to 1 in the SEM field     FLAG2 One 0 = Cumulative ACK
1 = Selective ACK MAP existence     SSN xxx FLAG2 = 0, ARQ sub-block up to and including SSN has been received successfully.
FLAG2 = 1, ARQ sub-block less than SSN has been received successfully     while (FLAG2 == 1) {      Selective ACK MAP2 7 Each bit represents ACK or NAK of corresponding ARQ sub-block '0' is NAK and '1' is ACK.
First MSB of first Selective ACK MAP2 represents ACK or NAK information of SSN. Contiguous bits after first MSB of first selective ACK MAP2 are corresponding to contiguous SSN.      FLAG2 One 0 = No more selective ACK MAP2 and FLAG2
1 = Another set of selective ACK MAP2 and FLAG2 follows     }    }    Padding variable For Byte alignment   }  } }

Here, the ARQ feedback information is included in the LAST field indicating whether there is other ARQ feedback information, a Flow ID field indicating an identifier (ID) of a connector (Connetction or Flow) to which ARQ is applied, an ARQ block among a cumulative ACK scheme and a selection ACK map. A FLAG1 field indicating a method used for feeding back ACK / NACK information for the ACK / NACK information, and an SN field indicating a sequence number of the ARQ block included in the ARQ feedback information of the cumulative ACK method. Here, the LAST field indicates whether ARQ feedback information having a Flow ID different from that of <Table 1> is present after <Table 1>. When the FLAG1 is '0', the SN field indicates a value having the largest ARQ sequence number among ARQ blocks which have been successfully received. In addition, when the FLAG1 is '1', the SN field indicates an ARQ sequence number of an ARQ block which has failed to be received first.

If the FLAG1 field is '1', the ARQ feedback information includes an ExT field indicating whether the ARQ feedback information includes ACK / NACK information of an ARQ subblock for an ARQ block and whether an error occurs using a cumulative ACK scheme. It further comprises a selection ACK map 1 field indicating whether an error of the ARQ blocks that do not indicate the, and the FLAG1 field indicating whether there is an additional selection ACK map 1 field. Here, the ExT field is composed of ARQ subblocks among ARQ blocks in which an error occurs, and indicates whether an ARQ block in which an error occurs exists in only some ARQ subblocks. Accordingly, the ExT field is displayed as '0' if the ACK / NACK information for the ARQ lower block is not included in the ARQ feedback information and '1' if the ACK / NACK information for the ARQ lower block is included.

When the ExT field is '1', the ARQ feedback information is composed of ARQ subblocks among ARQ blocks in which an error occurs, and a SEM field indicating an ARQ block in which only some ARQ subblocks have an error, For each ARQ block indicated by 1 ', a FLAG2 field indicating a method used for feeding back ACK / NACK information for the ARQ sub-block among the cumulative ACK method and the selection ACK map, and the ARQ feedback information in the cumulative ACK method or the selection ACK method. SSN field indicating the sequence number of the ARQ sub-blocks included, when using the selection ACK scheme, it further comprises a selection ACK map 2 field indicating whether an error occurs in the ARQ sub-blocks. Here, the SEM field is composed of ARQ subblocks among ARQ blocks in which an error occurs, and when a partial ARQ subblock is successfully received, the SEM field is indicated as '1'. In addition, the SEM field may indicate an ARQ block having an error in all ARQ sub-blocks but not composed of ARQ sub-blocks among ARQ blocks having an error, or ARQ sub-blocks.

The receiving end may add the ARQ feedback information of the ARQ lower block to the ARQ feedback information of the ARQ block by using the ExT field and the SEM field as shown in Table 2 below. In this case, it is assumed that the receiving end configures ARQ feedback information for the ARQ block using the cumulative ACK method and the selection ACK method, and configures the ARQ feedback information for the ARQ lower block using the selection ACK method. Here, the receiving end generates ARQ feedback information in the form of an information element (IE).

Syntax Size (bit) Notes ARQ_feedback_IE (LAST) { variable  Last One 0 = More ARQ Feedback IE in the list
1 = Last ARQ Feedback IE in the list  Flow ID 4 The ID of the connection (flow) being referenced  FLAG1 One 0 = Cumulative ACK
1 = Selective ACK MAP existence  SN 10 FLAG = 0, ARQ block up to and including SN has been received successfully.
FLAG = 1, ARQ block less than SN has been received successfully.  if (FLAG1 == 1) {   Selective ACK MAP 1 6 Each bit represents ACK or NAK of corresponding ARQ block. '0' is NAK and '1' is ACK.
First MSB of first Selective ACK MAP1 represents ACK or NAK information of SN. Contiguous bits after first MSB of first ACK MAP are corresponding to contiguous SN.   ExT One Extension for ARQ sub-block indication
0 = No ARQ sub-block ACK / NACK indication
1 = ARQ sub-block ACK / NACK indication follows   FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and FLAG1 follows   while (FLAG1 == 1) {    Selective ACK MAP1 7 Each bit represents ACK or NAK of corresponding ARQ block. '0' is NAK and '1' is ACK.
Selective ACK MAP1 represents ACK or NAK information of ARQ blocks after first selective ACK MAP1.    FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and FLAG1 follows   }   if (Ext == 1) {    SEM variable Sub-block-Existence Map

The numbers of SEM bits are same as nacked ARQ block in the Selective ACK MAP1.Each bit represents the existence of partially nacked ARQ blocks or completely nacked ARQ blocks.

1 = Partially nacked ARQ block (the ARQ block has some sub-blocks which have received correctly)
0 = Completely nacked ARQ blocks (the ARQ block has no sub-blocks which have received correctly)    for (i = 0; i <Num_block <i ++) { Num_block is the number of bits equal to 1 in the SEM field     Do {      Selective ACK MAP2 7 Each bit represents ACK or NAK of corresponding ARQ sub-block. '0' is NAK and '1' is ACK.
First MSB of first Selective ACK MAP2 represents ACK or NAK information of first ARQ sub-block of ARQ block. Contiguous bits after first MSB of first selective ACK2 are corresponding to contiguous SSN.      FLAG2 One 0 = No more selective ACK MAP2 and FLAG2
1 = Another set of selective ACK MAP2 and FLAG2 follows      } while (FLAG2 == 1)    }    Padding variable For Byte alignment   }  } }

Here, the ARQ feedback information is included in the LAST field indicating whether there is other ARQ feedback information, a Flow ID field indicating an identifier (ID) of a connector (Connetction or Flow) to which ARQ is applied, an ARQ block among a cumulative ACK scheme and a selection ACK map. A FLAG1 field indicating a method used for feeding back ACK / NACK information for the ACK / NACK information, and an SN field indicating a sequence number of the ARQ block included in the ARQ feedback information of the cumulative ACK method. Here, the LAST field indicates whether ARQ feedback information having a Flow ID different from that of <Table 2> is present after <Table 2>. When the FLAG1 is '0', the SN field indicates a value having the largest ARQ sequence number among ARQ blocks which have been successfully received. In addition, when the FLAG1 is '1', the SN field indicates an ARQ sequence number of an ARQ block which has failed to be received first.

If the FLAG1 field is '1', the ARQ feedback information includes an ExT field indicating whether the ARQ feedback information includes ACK / NACK information of an ARQ subblock for an ARQ block and whether an error occurs using a cumulative ACK scheme. It further comprises a selection ACK map1 field indicating whether an error occurs in the ARQ blocks that do not indicate the, and the FLAG1 field indicating whether there is an additional selection ACK map1 field. Here, the ExT field is composed of ARQ subblocks among ARQ blocks in which an error occurs, and indicates whether an ARQ block in which an error occurs exists in only some ARQ subblocks. Accordingly, the ExT field is displayed as '0' if the ACK / NACK information for the ARQ lower block is not included in the ARQ feedback information and '1' if the ACK / NACK information for the ARQ lower block is included.

When the ExT field is '1', the ARQ feedback information is composed of ARQ subblocks among ARQ blocks in which an error occurs, and a SEM field indicating an ARQ block in which only some ARQ subblocks have an error, And a selection ACK map2 field indicating whether an error occurs in the ARQ subblocks constituting each ARQ block indicated by 1 ', and a FLAG2 field indicating whether an additional selection ACK map2 field exists. Here, the SEM field is composed of ARQ subblocks among ARQ blocks in which an error occurs, and represents an ARQ block in which an error occurs only in some ARQ subblocks as '1'. In addition, the SEM field may indicate an ARQ block having an error in all ARQ sub-blocks but not composed of ARQ sub-blocks among ARQ blocks having an error, or ARQ sub-blocks.

The receiving end may add the ARQ feedback information of the ARQ lower block to the ARQ feedback information of the ARQ block using the ExT field and the SEM field as shown in Table 3 below. In this case, it is assumed that the receiving end configures ARQ feedback information for the ARQ block using the cumulative ACK method and the selection ACK method, and configures the ARQ feedback information for the ARQ lower block using the cumulative ACK method and the sequence ACK method. do. For example, when using the sequence ACK scheme, the receiving end does not indicate ACK / NACK information for each ARQ subblock, but represents ACK / NACK information of ARQ subblocks by group. Here, the receiving end generates ARQ feedback information in the form of an information element (IE).

Syntax Size (bit) Notes ARQ_feedback_IE (LAST) { variable  Last One 0 = More ARQ Feedback IE in the list
1 = Last ARQ Feedback IE in the list  Flow ID 4 The ID of the connection (flow) being referenced  FLAG1 One 0 = Cumulative ACK
1 = Selective ACK MAP existence  SN 10 FLAG = 0, ARQ block up to and including SN has been received successfully.
FLAG = 1, ARQ block less than SN has been received successfully.  if (FLAG1 == 1) {   Selective ACK MAP 1 6 Each bit represents ACK or NAK of corresponding ARQ block. '0' is NAK and '1' is ACK.
First MSB of first Selective ACK MAP1 represents ACK or NAK information of SN. Contiguous bits after first MSB of first ACK MAP are corresponding to contiguous SN.   ExT One Extension for ARQ sub-block indication
0 = No ARQ sub-block ACK / NACK indication
1 = ARQ sub-block ACK / NACK indication follows   FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and FLAG1 follows   while (FLAG1 == 1) {    Selective ACK MAP1 7 Each bit represents ACK or NAK of corresponding ARQ block. '0' is NAK and '1' is ACK.
Selective ACK MAP1 represents ACK or NAK information of ARQ block after first selective ACK MAP1.    FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and FLAG1 follows   }   if (Ext == 1) {    SEM variable Sub-block-Existence bitMap

The numbers of SEM bits are same as NACKed ARQ block in the Selective ACK MAP1.Each bit represents the existence of partially nacked ARQ blocks or completely nacked ARQ blocks.

1 = Partially nacked ARQ block (the ARQ block has some sub-blocks which have received correctly)
0 = Completely nacked ARQ blocks (the ARQ block has no sub-blocks which have received correctly)    for (i = 0; i <Num_block <i ++) { Num_block is the number of bits equal to 1 in the SEM field     FLAG2 One 0 = Cumulative ACK
1 = Sequence ACK MAP existence     SSN xxx ARQ sub-block sequence number     while (FLAG2 == 1) {      Sequence format One 0 = 2 blocks sequence format
1 = 3 blocks sequence format      if (Sequence format == 0) {       Sequence ACK MAP 2 Each bit represents set of ARQ sub-blocks are received correctly or not. MSB of sequence ACK MAP represents ACK or NAK information of first group of ARQ-sub-blocks.
1 = Number of the ARQ blocks in the Sequence x Length field received correctly
0 = Number of ARQ blocks in the Sequence x Length field received incorrectly.       Sequence 1 Length 6 Number of ARQ sub-blocks. MSB of sequence ACK MAP is corresponding to Sequence 1 Length field.       Sequence 2 Length 6 Number of ARQ sub-blocks. LSB of sequence ACK MAP is corresponding to Sequence 2 Length field.      }      else {       Sequence ACK MAP 3 Each bit represents set of ARQ sub-blocks are received correctly or not. MSB of first sequence ACK MAP represents ACK or NAK information of first group of ARQ-sub-blocks.
1 = Number of the ARQ blocks in the Sequence x Length field received correctly
0 = Number of ARQ blocks in the Sequence x Length field received incorrectly.       Sequence 1 Length 3 Number of ARQ sub-blocks. MSB of sequence ACK MAP is corresponding to Sequence 1 Length       Sequence 2 Length 4 Number of ARQ sub-blocks. Second Bit of sequence ACK MAP is corresponding to Sequence 2 Length field.       Sequence 3 Length 4 Number of ARQ sub-blocks. LSB of sequence ACK MAP is corresponding to Sequence 3 Length field.      }      FLAG2 One 0 = No more sequence ACK MAP
1 = Another set of sequence ACK MAP and FLAG2 follows     }    }    Padding variable For Byte alignment   }  } }

Here, the ARQ feedback information is included in the LAST field indicating whether there is other ARQ feedback information, a Flow ID field indicating an identifier (ID) of a connector (Connetction or Flow) to which ARQ is applied, an ARQ block among a cumulative ACK scheme and a selection ACK map. A FLAG1 field indicating a method used for feeding back ACK / NACK information for the ACK / NACK information, and an SN field indicating a sequence number of the ARQ block included in the ARQ feedback information of the cumulative ACK method. Here, the LAST field indicates whether ARQ feedback information having a Flow ID different from that of <Table 3> is present after <Table 3>. When the FLAG1 is '0', the SN field indicates a value having the largest ARQ sequence number among ARQ blocks which have been successfully received. In addition, when the FLAG1 is '1', the SN field indicates an ARQ sequence number of an ARQ block which has failed to be received first.

If the FLAG1 field is '1', the ARQ feedback information includes an ExT field indicating whether the ARQ feedback information includes ACK / NACK information of an ARQ subblock for an ARQ block and whether an error occurs using a cumulative ACK scheme. It further comprises a selection ACK map1 field indicating whether an error occurs in the ARQ blocks that do not indicate the, and the FLAG1 field indicating whether there is an additional selection ACK map1 field. Here, the ExT field is composed of ARQ subblocks among ARQ blocks in which an error occurs, and indicates whether an ARQ block in which an error occurs exists in only some ARQ subblocks. Accordingly, the ExT field is displayed as '0' if the ACK / NACK information for the ARQ lower block is not included in the ARQ feedback information and '1' if the ACK / NACK information for the ARQ lower block is included.

When the ExT field is '1', the ARQ feedback information is composed of ARQ subblocks among ARQ blocks in which an error occurs, and a SEM field indicating an ARQ block in which only some ARQ subblocks have an error, ARQ feedback information of a FLAG2 field, a cumulative ACK method, and a sequence ACK map method indicating a method used for feeding back the ACK / NACK information for the ARQ sub-block among the cumulative ACK method and the sequence ACK map for each ARQ block indicated by 1 '. SSN field indicating the sequence number of the ARQ subblock included in the sequence, a sequence format field indicating the sequence format for indicating the ACK / NACK information of the ARQ subblock, and a group indicating the ACK / NACK information of the ARQ subblocks. A sequence ACK map field indicating ACK / NACK information, a sequence K length field indicating the number of ARQ subblocks indicating ACK / NACK information through a k-th group, The gajeok the sequence FLAG2 field indicating whether the ACK Map field exists further includes. Here, the SEM field is composed of ARQ subblocks among ARQ blocks in which an error occurs, and represents an ARQ block in which an error occurs only in some ARQ subblocks as '1'. In addition, the SEM field may indicate an ARQ block having an error in all ARQ sub-blocks but not composed of ARQ sub-blocks among ARQ blocks having an error, or ARQ sub-blocks.

For example, if the ARQ block is composed of 10 ARQ subblocks, the first 5 ARQ subblocks are ACK, and the last 5 ARQ subblocks are NACK, the receiving end is set to 2 in <Table 3>. The sequence ACK map composed of bits is represented by '10', the sequence 1 length is represented by '5', and the sequence 2 length is represented by '5'.

The receiving end may add the ARQ feedback information of the ARQ lower block to the ARQ feedback information of the ARQ block using the ExT field and the SEM field as shown in Table 4 below. In this case, it is assumed that the receiving end configures ARQ feedback information on an ARQ block using a cumulative ACK scheme and a selective ACK scheme, and configures ARQ feedback information on an ARQ subblock using a sequence ACK scheme. For example, when using the sequence ACK scheme, the receiving end does not indicate ACK / NACK information for each ARQ subblock, but represents ACK / NACK information of ARQ subblocks by group. Here, the receiving end generates ARQ feedback information in the form of an information element (IE).

Syntax Size (bit) Notes ARQ_feedback_IE (LAST) { variable  Last One 0 = More ARQ Feedback IE in the list
1 = Last ARQ Feedback IE in the list  Flow ID 4 The ID of the connection (flow) being referenced  FLAG1 One 0 = Cumulative ACK
1 = Selective ACK MAP existence  SN 10 FLAG = 0, ARQ block up to and including SN has been received successfully.
FLAG = 1, ARQ block less than SN has been received successfully.  if (FLAG1 == 1) {   Selective ACK MAP 1 6 Each bit represents ACK or NAK of corresponding ARQ block. '0' is NAK and '1' is ACK.
First MSB of first Selective ACK MAP1 represents ACK or NAK information of SN. Contiguous bits after first MSB of first ACK MAP are corresponding to contiguous SN.   ExT One Extension for ARQ sub-block indication
0 = No ARQ sub-block ACK / NACK indication
1 = ARQ sub-block ACK / NACK indication follows   FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and FLAG1 follows   while (FLAG1 == 1) {    Selective ACK MAP1 7 Each bit represents ACK or NAK of corresponding ARQ block. '0' is NAK and '1' is ACK.
Selective ACK MAP1 represents ACK or NAK information of ARQ block after first selective ACK MAP1.    FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and FLAG1 follows   }   if (Ext == 1) {    SEM variable Sub-block-Existence bitMap

The numbers of SEM bits are same as NACKed ARQ block in the Selective ACK MAP1.Each bit represents the existence of partially nacked ARQ blocks or completely nacked ARQ blocks.

1 = Partially nacked ARQ block (the ARQ block has some sub-blocks which have received correctly)
0 = Completely nacked ARQ blocks (the ARQ block has no sub-blocks which have received correctly)    for (i = 0; i <Num_block <i ++) { Num_block is the number of bits equal to 1 in the SEM field     Do {      Sequence format One 0 = 2 blocks sequence format
1 = 3 blocks sequence format      if (Sequence format == 0) {       Sequence ACK MAP 2 Each bit represents set of ARQ sub-blocks are received correctly or not. MSB of sequence ACK MAP represents ACK or NAK information of first group of ARQ-sub-blocks.
1 = Number of the ARQ blocks in the Sequence x Length field received correctly
0 = Number of ARQ blocks in the Sequence x Length field received incorrectly.       Sequence 1 Length 6 Number of ARQ sub-blocks. MSB of sequence ACK MAP is corresponding to Sequence 1 Length field.       Sequence 2 Length 6 Number of ARQ sub-blocks. LSB of sequence ACK MAP is corresponding to Sequence 2 Length field.      }      else {       Sequence ACK MAP 3 Each bit represents set of ARQ sub-blocks are received correctly or not. MSB of first sequence ACK MAP represents ACK or NAK information of first group of ARQ-sub-blocks.
1 = Number of the ARQ blocks in the Sequence x Length field received correctly
0 = Number of ARQ blocks in the Sequence x Length field received incorrectly.       Sequence 1 Length 3 Number of ARQ sub-blocks. MSB of sequence ACK MAP is corresponding to Sequence 1 Length       Sequence 2 Length 4 Number of ARQ sub-blocks. Second Bit of sequence ACK MAP is corresponding to Sequence 2 Length field.       Sequence 3 Length 4 Number of ARQ sub-blocks. LSB of sequence ACK MAP is corresponding to Sequence 3 Length field.      }      FLAG2 One 0 = No more sequence ACK MAP
1 = Another set of sequence ACK MAP and FLAG2 follows     } while (FLAG2 == 1)    }    Padding variable For Byte alignment   }  } }

Here, the ARQ feedback information is included in the LAST field indicating whether there is other ARQ feedback information, a Flow ID field indicating an identifier (ID) of a connector (Connetction or Flow) to which ARQ is applied, an ARQ block among a cumulative ACK scheme and a selection ACK map. A FLAG1 field indicating a method used for feeding back ACK / NACK information for the ACK / NACK information, and an SN field indicating a sequence number of the ARQ block included in the ARQ feedback information of the cumulative ACK method. Here, the LAST field indicates whether ARQ feedback information having a Flow ID different from that of <Table 4> is present after <Table 4>. When the FLAG1 is '0', the SN field indicates a value having the largest ARQ sequence number among ARQ blocks which have been successfully received. In addition, when the FLAG1 is '1', the SN field indicates an ARQ sequence number of an ARQ block which has failed to be received first.

If the FLAG1 field is '1', the ARQ feedback information includes an ExT field indicating whether the ARQ feedback information includes ACK / NACK information of an ARQ subblock for an ARQ block and whether an error occurs using a cumulative ACK scheme. It further comprises a selection ACK map1 field indicating whether an error occurs in the ARQ blocks that do not indicate the, and the FLAG1 field indicating whether there is an additional selection ACK map1 field. Here, the ExT field is composed of ARQ subblocks among ARQ blocks in which an error occurs, and indicates whether an ARQ block in which an error occurs exists in only some ARQ subblocks. Accordingly, the ExT field is displayed as '0' if the ACK / NACK information for the ARQ lower block is not included in the ARQ feedback information and '1' if the ACK / NACK information for the ARQ lower block is included.

When the ExT field is '1', the ARQ feedback information is composed of ARQ subblocks among ARQ blocks in which an error occurs, and a SEM field indicating an ARQ block in which only some ARQ subblocks have an error, For each ARQ block indicated by 1 ', a sequence format field indicating a sequence format for indicating ACK / NACK information of an ARQ subblock, and ACK / NACK information of a group indicating ACK / NACK information of ARQ subblocks. And a sequence K length field indicating the number of ARQ subblocks indicating the ACK / NACK information through the k-th group, and a FLAG2 field indicating whether an additional sequence ACK map field exists. Here, the SEM field is composed of ARQ subblocks among ARQ blocks in which an error occurs, and represents an ARQ block in which an error occurs only in some ARQ subblocks as '1'. In addition, the SEM field may indicate an ARQ block having an error in all ARQ sub-blocks but not composed of ARQ sub-blocks among ARQ blocks having an error, or ARQ sub-blocks.

The receiving end may add the ARQ feedback information of the ARQ lower block to the ARQ feedback information of the ARQ block by using the ExT field and the SEM field as shown in Table 5 below. In this case, it is assumed that the receiving end configures ARQ feedback information for the ARQ block using the cumulative ACK scheme and the selective ACK scheme, and configures the ARQ feedback information for the ARQ lower block using the continuous ACK scheme. For example, when using the continuous ACK scheme, the receiving end does not indicate ACK / NACK information for each ARQ subblock, but represents ACK information of the ARQ subblocks by group. In this case, the ACK information of the ARQ lower blocks indicates only information on the ARQ lower block which is successfully received at the receiving end. Accordingly, the transmitting end recognizes that the receiving end is not successful in receiving the ARQ lower block that is not marked as ACK in the ACK information for the ARQ lower block provided from the receiving end. Here, the receiving end generates ARQ feedback information in the form of an information element (IE).

Syntax Size (bit) Notes ARQ_feedback_IE (LAST) { variable  Last One 0 = More ARQ Feedback IE in the list
1 = Last ARQ Feedback IE in the list  Flow ID 4 The ID of the connection (flow) being
referenced  FLAG1 One 0 = Cumulative ACK
1 = Selective ACK MAP existence  SN 10 FLAG = 0, ARQ block up to and including
SN has been received successfully.
FLAG = 1, ARQ block less than SN has been
received successfully.  if (FLAG1 == 1) {   Selective ACK MAP 1 6 Each bit represents ACK or NAK of
corresponding ARQ block. '0' is NAK and
'1' is ACK.
First MSB of first Selective ACK MAP1
represents ACK or NAK information of SN.
Contiguous bits after first MSB of first
ACK MAP are corresponding to contiguous
SN.   ExT One Extension for ARQ sub-block indication
0 = No ARQ sub-block ACK / NACK indication
1 = ARQ sub-block ACK / NACK indication
follows   FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and
FLAG1 follows   while (FLAG1 == 1) {    Selective ACK MAP1 7 Each bit represents ACK or NAK of
corresponding ARQ block. '0' is NAK and
'1' is ACK.
Selective ACK MAP1 represents ACK or NAK
information of ARQ block after first
selective ACK MAP1.    FLAG1 One 0 = No more selective ACK MAP1 and FLAG1
1 = Another set of selective ACK MAP1 and
FLAG1 follows   }   if (Ext == 1) {    SEM variable Sub-block-Existence bitMap

The numbers of SEM bits are same as
NACKed ARQ block in the Selective ACK
MAP1.Each bit represents the existence of
partially nacked ARQ blocks or completely
nacked ARQ blocks.

1 = Partially nacked ARQ block (the ARQ
block has some sub-blocks which have
received correctly)
0 = Completely nacked ARQ blocks (the ARQ
block has no sub-blocks which have
received correctly)    for (i = 0; i <Num_block <i ++) { Num_block is the number of bits equal to
1 in the SEM field     do {       START_SSN xxx Start of ARQ sub-block SN which was
received correctly       Num_SSN xxx Number of consecutive ARQ sub-blocks
which were received correctly from
START_SSN onwards       End One 0 = One more set of START_SSN. Length and
End fields
1 = There are no more START_SSN, NUM_SSN
and End fields       } while (End == 0)    }    Padding variable For Byte alignment   }  } }

Here, the ARQ feedback information is included in the LAST field indicating whether there is other ARQ feedback information, a Flow ID field indicating an identifier (ID) of a connector (Connetction or Flow) to which ARQ is applied, an ARQ block among a cumulative ACK scheme and a selection ACK map. A FLAG1 field indicating a method used for feeding back ACK / NACK information for the ACK / NACK information, and an SN field indicating a sequence number of the ARQ block included in the ARQ feedback information of the cumulative ACK method. Here, the LAST field indicates whether ARQ feedback information having a Flow ID different from that of <Table 5> is present after <Table 5>. When the FLAG1 is '0', the SN field indicates a value having the largest ARQ sequence number among ARQ blocks which have been successfully received. In addition, when the FLAG1 is '1', the SN field indicates an ARQ sequence number of an ARQ block which has failed to be received first.

If the FLAG1 field is '1', the ARQ feedback information includes an ExT field indicating whether the ARQ feedback information includes whether to receive the ARQ subblock for the ARQ block and whether an error occurs using a cumulative ACK scheme. It further comprises a selection ACK map1 field indicating whether an error occurs in the ARQ blocks that do not indicate the, and the FLAG1 field indicating whether there is an additional selection ACK map1 field. Here, the ExT field is composed of ARQ subblocks among ARQ blocks in which an error occurs, and indicates whether an ARQ block in which an error occurs exists in only some ARQ subblocks. Accordingly, the ExT field is displayed as '0' when ARQ feedback information does not include information on whether to receive the ARQ subblock, and as '1' when information on reception on the ARQ subblock is included.

When the ExT field is '1', the ARQ feedback information is composed of ARQ subblocks among ARQ blocks in which an error occurs, and a SEM field indicating an ARQ block in which only some ARQ subblocks have an error, For each ARQ block indicated by 1 ', a START_SSN field indicating the sequence number (SSN) of the first ARQ subblock that was successfully received by the receiving end of the ARQ subblocks, and ARQs successively received after the first ARQ subblock that was successfully received. A Num_SSN field indicating the number of blocks and an End field indicating the number of repetitions of the START_SSN field and the Num_SSN field are configured. That is, when the receiving end configures the ARQ feedback information for the ARQ subblock using the continuous ACK scheme, the receiving end displays only information on the ARQ subblock successfully received in one ARQ block including the ARQ subblocks. Configure the ARQ feedback information. Accordingly, the receiving end may indicate whether an ARQ lower block is received using the START_SSN field, the Num_SSN field, and the End field. For example, when the transmitting end transmits one ARQ block composed of 100 ARQ subblocks, the receiving end successfully receives ARQ subblocks 1 to 30 and 61 to 90, and 31 It is assumed that ARQ subblocks 1 through 60 and 91 through 100 are not received successfully. In this case, the receiver sets the START_SSN field to '1', the Num_SSN field to '30', and the End field to '0' to indicate whether the ARQ subblocks 1 through 30 are received. Set to. In addition, the receiver sets the START_SSN field to '61', the Num_SSN field to '90', and the End field to '1' to indicate whether the ARQ subblocks 61 to 90 are received. Set to.

In this case, the transmitting end recognizes that an error has occurred in ARQ lower blocks 31 through 60, which are not indicated in the ARQ feedback information of the ARQ lower block. Accordingly, the transmitting end may retransmit the ARQ lower blocks 31 through 60.

Also, the transmitting end recognizes that the ARQ has not yet received the ARQ subblocks for the ARQ subblocks 91 to 100. If the transmitting end recognizes that the transmission failed for the ARQ lower blocks 91 through 100, the transmitting end may retransmit the ARQ lower blocks from 91 to 100.

As described above, the receiver adds the ARQ feedback information of the ARQ lower block to the ARQ feedback information of the ARQ block by using the ExT field and the SEM field. In this case, the receiving end configures ARQ feedback information and transmits it to the transmitting end as shown in FIG. 3.

3 illustrates a procedure for generating an ARQ feedback message at a receiving end of a wireless communication system according to an embodiment of the present invention.

Referring to FIG. 3, the receiving end checks whether an ARQ block is received from the transmitting end in step 301.

When the ARQ block is received, the receiver proceeds to step 303 and checks whether an error occurs in the received ARQ block.

In step 305, the receiving end determines whether to perform ARQ feedback.

If the ARQ feedback is not performed, the receiver returns to step 301 and checks whether an ARQ block is received from the transmitter.

On the other hand, when performing ARQ feedback, the receiver proceeds to step 307 to determine whether there is an ARQ block in which an error occurs among the ARQ blocks for performing ARQ feedback.

If there is no ARQ block in which an error occurs, the receiver proceeds to step 317 to generate ARQ feedback information for the ARQ block using a cumulative ACK scheme. For example, if an error does not occur in ARQ blocks 1 to 10 for performing ARQ feedback, the receiving end may perform the <Table 1> or <Table 2> or <Table 3> or <Table 4>. > Or <Table 5> generates ARQ feedback information in which the FLAG1 field is '0' and the SN field is '10'.

After generating the ARQ feedback information, the receiving end proceeds to step 319 to generate an ARQ feedback message including the generated ARQ feedback information and transmits it to the transmitting end.

If there is an ARQ block in which an error occurs in step 307, the receiver proceeds to step 309 to generate feedback information on the ARQ block using a cumulative ACK method and a selective ACK method. For example, the receiving end may be configured such that the SN field in <Table 1> or <Table 2> or <Table 3> or <Table 4> or <Table 5> includes a sequence number of an ARQ block in which an error occurs for the first time. Set it. In addition, the receiving end generates ARQ feedback information by configuring a selection ACK map to indicate whether an error occurs in ARQ blocks that do not indicate whether an error occurs using the accumulated ACK ARQ feedback information.

After generating ARQ feedback information for the ARQ block, the receiver proceeds to step 311 to check whether there is an ARQ block composed of ARQ lower blocks among ARQ blocks in which an error occurs.

If there is no ARQ block composed of ARQ sub-blocks, the receiving end proceeds to step 319 to generate an ARQ feedback message including ARQ feedback information for the ARQ block generated in step 309 and the transmitting end. To send.

On the other hand, if there is an ARQ block composed of ARQ subblocks, the receiver proceeds to step 313 to determine whether there is an ARQ block including an ARQ subblock successfully received among the ARQ blocks composed of ARQ subblocks. .

If there is no ARQ block including the ARQ subblock that has been successfully received, the receiving end recognizes that an error has occurred in all ARQ subblocks constituting the ARQ block. In this case, the receiving end may indicate NACK information for the ARQ lower blocks using only the NACK information for the ARQ block. Accordingly, the receiver proceeds to step 319 to generate an ARQ feedback message including ARQ feedback information on the ARQ block generated in step 309 and transmits the ARQ feedback message to the transmitter.

If there is an ARQ block including the ARQ subblock successfully received in step 313, the receiver proceeds to step 315 to generate feedback information on the ARQ subblock using the ExT field and the SEM field in step 309. Add to the feedback information. For example, the receiving end uses the ExT field and the SEM field as shown in <Table 1> or <Table 2> or <Table 3> or <Table 4> or <Table 5> to provide feedback information on the ARQ lower block. Is added to the feedback information of the ARQ block. That is, the receiving end indicates whether the SEM field exists using the ExT field, and indicates the ARQ block to include feedback information on the ARQ lower block using the SEM field. In addition, the receiving end generates feedback information of the ARQ lower block for the ARQ block in which the bit of the SEM field is set to '1' and adds the feedback information to the feedback information of the ARQ block.

After adding the feedback information of the ARQ lower block to the feedback information of the ARQ block, the receiving end proceeds to step 319 and ARQ block feedback information of the ARQ block to which the feedback information of the ARQ sub-block is added in step 315 A feedback message is generated and transmitted to the transmitting end.

Thereafter, the receiving end transmits the ARQ feedback message to the transmitting end.

Hereinafter, a description will be given of a method for checking whether an error occurs for an ARQ block and an ARQ lower block through ARQ feedback information at a transmitting end.

4 illustrates a procedure for transmitting an ARQ block in a transmitting end of a wireless communication system according to an embodiment of the present invention.

Referring to FIG. 4, in step 401, the transmitting end generates ARQ blocks and transmits them to the receiving end in order to provide an ARQ communication service. For example, the transmitting end generates the ARQ block according to the scheduling for the service data unit provided from the higher layer. Thereafter, the transmitting end may generate an MPDU (MAC Protocol Data Unit) with at least one ARQ block. In another example, the transmitting end generates an ARQ block by dividing one service data unit provided from a higher layer or combining a plurality of service data units. Thereafter, the transmitting end generates one MPDU with one ARQ block.

In step 403, the transmitter determines whether an ARQ feedback message is received from the receiver that transmitted the ARQ blocks.

When the ARQ feedback message is received, the transmitter proceeds to step 405 and checks whether an error occurs for ARQ blocks transmitted to the receiver through the ARQ feedback information included in the ARQ feedback message.

After checking whether an error has occurred in the ARQ blocks transmitted to the receiver, the transmitter proceeds to step 407 to determine whether the ARQ feedback message includes feedback information of the ARQ lower block. For example, the transmitter determines whether the ARQ feedback message includes feedback information of the ARQ lower block in consideration of the setting value of the ExT field of the ARQ feedback message. That is, when the ExT field is '0', the transmitting end recognizes that the ARQ feedback message does not include the feedback information of the ARQ lower block. Meanwhile, when the ExT field is '1', the transmitting end recognizes that the ARQ feedback message includes feedback information of an ARQ lower block.

If the ARQ feedback message does not include the feedback information of the ARQ lower block, the transmitter proceeds to step 411 and determines whether there is an ARQ block to be retransmitted according to whether an error of the ARQ blocks identified in step 405 occurs.

On the other hand, if the ARQ feedback message includes feedback information of the ARQ lower block, the transmitter proceeds to step 409 in which an error of the ARQ lower block occurs in consideration of the SEM field and the selection ACK map2 field of the ARQ feedback message. Check it. For example, the transmitting end is composed of ARQ subblocks through the SEM field, and identifies an ARQ block in which only some ARQ subblocks have an error. Thereafter, the transmitter determines whether there is an ARQ subblock in which an error occurs among the ARQ subblocks constituting the ARQ block through a bit value of the selection ACK map2 field.

In step 411, the transmitter determines whether an ARQ block and an ARQ subblock to be retransmitted exist according to whether an error occurs in the ARQ blocks identified in step 405 and whether an error occurs in the ARQ subblocks identified in step 409. do.

If there is no ARQ block and ARQ subblock to be retransmitted, the transmitting end terminates the present algorithm. At this time, the transmitting end transmits a new ARQ block to the receiving end.

If there is an ARQ block and an ARQ subblock to be retransmitted, the transmitter proceeds to step 413 to retransmit the ARQ block and the ARQ subblock to be retransmitted to the receiver.

Thereafter, the transmitting end terminates the present algorithm.

The following description describes the configuration of a transmitting end for transmitting an ARQ block or an ARQ subblock.

5 is a block diagram of a transmitter in a wireless communication system according to the present invention.

As illustrated in FIG. 5, the transmitting end includes a data storage unit 501, a data configuration unit 503, an ARQ control unit 505, a transmitter 507, a duplexer 509, a receiver 511, and an ARQ subblock. It is comprised including the part 513.

The data storage unit 501 stores data generated by an upper application program. For example, the data storage unit 501 is configured in the form of a data queue.

The data configuration unit 503 transforms the data structure 503 into a size for cutting or adding data stored in the data storage unit 501 according to scheduling information.

The ARQ control unit 505 generates an ARQ block for ARQ on the data provided from the data generation unit 503 and assigns a sequence number to each ARQ block. For example, the ARQ control unit 505 generates an ARQ block by dividing a service data unit (SDU) received from a higher layer into a predetermined data size. In this case, the ARQ controller 505 generates an MPDU (MAC Protocol Data Unit) with at least one ARQ block, and allocates an ARQ block sequence to the ARQ block according to the order of dividing the service data unit. For another example, the ARQ controller 505 divides one service data unit provided from a higher layer or combines a plurality of service data units to generate an ARQ block. In this case, the ARQ controller 505 generates one MPDU from one ARQ block and sequentially allocates an ARQ block sequence.

In addition, the ARQ controller 505 checks whether an error occurs in the ARQ blocks and the ARQ lower blocks transmitted to the receiver through an ARQ feedback message provided from the receiver. For example, the ARQ controller 505 checks whether an ARQ block error occurs in the ARQ feedback message and checks whether the ARQ feedback message includes feedback information of an ARQ lower block in consideration of a setting value of an ExT field. . That is, when the ExT field is '0', the ARQ controller 505 recognizes that the ARQ feedback message does not include the feedback information of the ARQ lower block. Meanwhile, when the ExT field is '1', the ARQ controller 505 recognizes that the ARQ feedback message includes feedback information of an ARQ lower block. If the ExT field is '1', the ARQ controller 505 checks whether an ARQ lower block has an error in consideration of the SEM field of the ARQ feedback message and the selection ACK map2 field. That is, the ARQ control unit 505 is composed of ARQ subblocks through the SEM field, and identifies an ARQ block in which an error occurs only in some ARQ subblocks. Thereafter, the ARQ controller 505 checks whether an error has occurred for the ARQ lower blocks constituting the ARQ block in consideration of the bit value of the selection ACK map2 field.

The ARQ controller 505 controls to retransmit the ARQ block in which the error occurs when an error occurs in the ARQ block transmitted or retransmitted to the receiver. For example, the ARQ control unit 505 determines whether to split the ARQ block to be retransmitted into ARQ subblocks. If it is determined that the ARQ block is to be divided, the ARQ control unit 505 controls the ARQ lower block configuration unit 513 to divide the ARQ block in which the error occurs into ARQ lower blocks. On the other hand, if it is determined that the ARQ block is not divided, the ARQ control unit 505 controls to retransmit the original ARQ block for the ARQ block in which the error occurs.

The ARQ lower block configuration unit 513 divides an ARQ block to be retransmitted into at least two ARQ subblocks due to an error under the control of the ARQ control unit 505. In this case, the ARQ lower block configuration unit 513 may divide the size of the ARQ lower block fixedly or variably.

The transmitter 507 includes a channel code block, a modulation block, and an RF processing block, converts at least one of an ARQ block and an ARQ lower block provided from the ARQ control unit 505 into a high frequency signal to thereby convert the duplexer 509. Transmit to the receiving end through. For example, the channel code block includes a channel encoder, an interleaver and a modulator. The modulation block consists of an Inverse Fast Fourier Transform (IFFT) operator in the orthogonal frequency division multiplexing scheme and a code spreading modulator in the code division multiple access scheme. The RF processing block converts the baseband signal provided from the modulation block into a high frequency signal and outputs it through an antenna.

The duplexer 509 transmits the transmission signal provided from the transmitter 507 through the antenna according to the duplexing scheme, and provides the reception signal from the antenna to the receiver 511.

The receiver 511 includes an RF processing block, a demodulation block, a channel decoding block, and the like, and converts and demodulates a high frequency signal provided from the duplexer 509 to a baseband signal. For example, the RF processing block converts a high frequency signal provided from the duplexer 509 into a baseband signal and outputs the baseband signal. The demodulation block includes an FFT operator for extracting data carried on each subcarrier from a signal provided from the RF processing block. The channel decoding block includes a demodulator, a deinterleaver, a channel decoder, and the like.

In the above configuration, the ARQ control unit 505 may perform a function of the ARQ lower block configuration unit 513. In the present invention, this is generated separately to describe each function separately. Therefore, in actual implementation, all of them may be configured to be processed by the ARQ controller 505, and only some of them may be configured to be processed by the ARQ controller 505.

The following description describes the configuration of a receiving end for generating an ARQ feedback message.

6 is a block diagram of a receiving end in a wireless communication system according to the present invention.

As shown in FIG. 6, the receiving end includes a duplexer 601, a receiver 603, an ARQ controller 605, a data recovery unit 607, a data storage unit 609, an ARQ control message generator 611, and the like. And a transmitter 613.

The duplexer 601 transmits a transmission signal provided from the transmitter 613 through an antenna according to a duplexing scheme, and provides a reception signal from the antenna to the receiver 603.

The receiver 603 includes an RF processing block, a demodulation block, a channel decoding block, and the like, and converts and demodulates a high frequency signal provided from the duplexer 601 into a baseband signal. For example, the RF processing block converts a high frequency signal provided from the duplexer 601 into a baseband signal and outputs the baseband signal. The demodulation block includes an FFT operator for extracting data carried on each subcarrier from a signal provided from the RF processing block. The channel decoding block includes a demodulator, a deinterleaver, a channel decoder, and the like.

The ARQ control unit 605 checks the sequence of the ARQ block and the ARQ subblock provided from the receiver 603 and checks whether an error occurs in the ARQ block and the ARQ subblock.

The ARQ control unit 605 checks an ARQ feedback time point and controls the ARQ control message generation unit 611 to generate an ARQ feedback message when an ARQ feedback time point arrives.

The data recovery unit 607 restores the data before cutting or merging the data by the data generation unit 503 of the transmitting end by using the ARQ blocks successfully received by the ARQ control unit 605 without error.

The data storage unit 609 stores the data restored by the data recovery unit 607, and transfers the data from an upper application program. For example, the data storage unit 609 is generated in the form of a data queue.

The ARQ control message generator 611 generates an ARQ feedback message to be transmitted to the transmitter under the control of the ARQ controller 605. For example, when an error occurs in the ARQ block received from the transmitting end, the ARQ control message generator 611 generates ARQ feedback information on the ARQ block by using the cumulative ACK method and the selective ACK method. At this time, the ARQ control message generation unit 611 adds feedback information on the ARQ lower block to ARQ feedback information on the ARQ block using the ExT field and the SEM field. That is, the ARQ control message generator 611 uses the ExT field and the SEM field as shown in <Table 1>, <Table 2>, <Table 3>, <Table 4>, or <Table 5> of the ARQ block. Add feedback information for the ARQ lower block to the feedback information. That is, the ARQ control message generation unit 611 indicates whether the SEM field exists using the ExT field, and indicates an ARQ block including feedback information on the ARQ lower block using the SEM field. In addition, the ARQ control message generation unit 611 generates feedback information of the ARQ lower block for the ARQ block in which the bit of the SEM field is set to '1' and adds the feedback information to the ARQ block.

The ARQ control message generator 611 is composed of ARQ subblocks among ARQ blocks in which an error occurs, and when an ARQ block in which an error occurs only in some ARQ subblocks exists, the ARQ subblock is included in feedback information of the ARQ block. Add feedback information for. Here, the ARQ control unit 605 checks whether an ARQ block composed of ARQ lower blocks among ARQ blocks having an error exists. In addition, the ARQ control unit 605 checks whether there is an ARQ block including at least one ARQ sub-block successfully received among the ARQ blocks in which the error occurs.

The transmitter 613 includes a channel code block, a modulation block, and an RF processing block. The transmitter 613 converts an ARQ feedback message provided from the ARQ controller 605 into a high frequency signal and transmits the high frequency signal to the receiver through the duplexer 601. do. For example, the channel code block includes a channel encoder, an interleaver and a modulator. The modulation block is generated by an IFFT operator in the orthogonal frequency division multiplexing scheme, and consists of a code spreading modulator in the code division multiple access scheme. The RF processing block converts the baseband signal provided from the modulation block into a high frequency signal and outputs it through an antenna.

In the above configuration, the ARQ controller 605 may perform a function of the ARQ control message generator 611. In the present invention, it is separately configured to describe each function separately. Therefore, in actual implementation, all of them may be configured to be processed by the ARQ controller 605, and only some of them may be configured to be processed by the ARQ controller 605.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications may be made 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 determined not only by the scope of the following claims, but also by the equivalents of the claims.

1 is a diagram illustrating a configuration of an ARQ block in a wireless communication system according to an embodiment of the present invention;

2 is a diagram illustrating a configuration of an ARQ feedback message in a wireless communication system according to an embodiment of the present invention;

3 is a diagram illustrating a procedure for generating an ARQ feedback message at a receiving end of a wireless communication system according to an embodiment of the present invention;

4 is a diagram illustrating a procedure for transmitting an ARQ block at a transmitting end of a wireless communication system according to an embodiment of the present invention;

5 is a block diagram of a transmitting end in a wireless communication system according to the present invention; and

6 is a block diagram of a receiving end in a wireless communication system according to the present invention;

Claims (20)

A method for transmitting an Automatic Repeat Request (ARQ) feedback message at an ARQ block receiving end of a wireless communication system, Receiving a plurality of ARQ blocks; Transmitting the ARQ feedback message including the first information, the second information, and the third information to the ARQ block transmitting end; The first information indicates one of an ACKed ARQ block and a NACKed ARQ block of the received ARQ block. The second information indicates that the NACK block is any one of a fully NACKed ARQ block and a partially NACKed ARQ block. The third information indicates whether reception of at least one ARQ subblock among ARQ subblocks for the partial NACK block is successful. The method of claim 1, The ACK block of the ARQ block, the reception success information of the ARQ block. The method of claim 1, And wherein the partially NACKed ARQ block indicates reception success information for at least one ARQ subblock among ARQ subblocks for the ARQ block. The method of claim 1, And the completely NACKed ARQ block indicates reception failure information of the ARQ sub-block for the ARQ block. The method of claim 1, The ARQ feedback message further includes fourth information indicating the presence of ACK / NACK of an ARQ subblock. The method of claim 1, The ARQ feedback message further includes fourth information indicating the presence of at least one of the second information and the third information. The method of claim 1, Wherein the third information indicates at least one of a sequence number of a first ARQ subblock successfully received in an ARQ block and a number of ARQ subblocks successively received from the first ARQ subblock. 8. The method of claim 7, The third information is based on a bitmap indicating whether an error of an ARQ lower block occurs, whether there is an additional bitmap, whether there is an additional second information, a configuration method of the second information, or a configuration method of the second information. The method further indicates at least one of the sequence number of the last ARQ subblock in which reception was successful or the first ARQ subblock in which an error occurred, the sequence number of the ARQ subblock, the sequence bitmap representing the ACK / NACK block of the sequence group, and the length of the sequence group. . The method of claim 1, The ARQ feedback message may include at least one of an identifier of a connector to which ARQ has been applied, a configuration method of first information, a last ARQ block successfully received according to a configuration method of first information, or a sequence number of an ARQ block in which an error occurs for the first time. The second information further. 10. The method of claim 9, The configuration method of the first information includes at least one of a cumulative ACK scheme and a selective ACK scheme. In the ARQ block receiving apparatus of a wireless communication system, A receiver for receiving a plurality of ARQ blocks, and A transmitter for transmitting ARQ feedback information including first information, second information, and third information to an ARQ block transmitting end; The first information indicates any one of an ACKed ARQ block and a NACKed ARQ block of an ARQ block. The second information indicates that the NACK block is any one of a fully NACKed ARQ block and a partially NACKed ARQ block. And the third information indicates whether reception of at least one ARQ subblock among ARQ subblocks for the partial NACK block is successful. 12. The method of claim 11, And an ACK block of the ARQ block indicates reception success information of an ARQ block. 12. The method of claim 11, And wherein the partially NACKed ARQ block indicates reception success information of at least one ARQ subblock among ARQ subblocks for the ARQ block. 12. The method of claim 11, And the completely NACKed ARQ block includes reception failure information of an ARQ sub-block for an ARQ block. 12. The method of claim 11, The ARQ feedback message further includes fourth information indicating the presence of ACK / NACK of an ARQ subblock. 12. The method of claim 11, The ARQ feedback message further includes fourth information indicating the presence of at least one of the second information and the third information. 12. The method of claim 11, Wherein the third information indicates at least one of a sequence number of a first ARQ subblock successfully received in an ARQ block and a number of ARQ subblocks successively received from the first ARQ subblock. The method of claim 17, The third information is based on a bitmap indicating whether an error of an ARQ lower block occurs, whether there is an additional bitmap, whether there is an additional second information, a configuration method of the second information, or a configuration method of the second information. An apparatus further indicating at least one of a sequence number of the last ARQ subblock in which reception was successful or an ARQ subblock in which an error first occurred, a sequence number of the ARQ subblock, a sequence bitmap indicating an ACK / NACK block of the sequence group, and a length of the sequence group . 12. The method of claim 11, The ARQ feedback message may include at least one of an identifier of a connector to which ARQ has been applied, a configuration method of first information, a last ARQ block successfully received according to a configuration method of first information, or a sequence number of an ARQ block in which an error occurs for the first time. The device further includes the first information. The method of claim 19, The configuration method of the first information includes at least one of a cumulative ACK scheme and a selective ACK scheme.

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