KR20100081901A - Method for transmitting and receiving data using random linear coding - Google Patents

Abstract

PURPOSE: A method for transmitting and receiving data is provided to provided coefficient matrix capable of always decoding the packets in case receiving a constant amount of packets in a receiving end, thereby performing effectively communication. CONSTITUTION: By applying a random encode(RLC) to a data block combination generated by dividing the higher class data into a predetermined size, a plurality of encoded blocks is generated(S101). A plurality of encoded blocks is transmitted to a receiving end(S103). Each row is performed by using coefficient matrix having independent characteristic in a galois filed which is preset(S107). Each element comprising a first row of coefficient matrix is shared in a transmitting end and receiving end. It is operated through an initial net entry procedure of transmitting end and receiving end.

Description

Method for transmitting and receiving data using Random Linear Coding}

The present invention relates to a wireless access system, and more particularly, to a communication method using random linear coding.

A communication system based on the Internet generally consists of a protocol stack consisting of five layers, and the configuration of each protocol layer is shown in FIG. 1.

1 is a diagram illustrating an example of a commonly used Internet protocol stack.

Referring to FIG. 1, the top layer of the protocol stack is an application layer, which is a layer for supporting network applications such as FTP / HTTP / SMTP / RTP. Next, there are a transport layer that performs data transmission function between hosts using a TCP / UDP protocol and a network layer that performs data transmission path setting from a source to a destination through an IP protocol. In addition, the protocol stack performs bit-by-bit transmission of data using wired or wireless media and a link layer that is responsible for data transmission and media access control (MAC) between peripheral network entities through a PPP / Ethernet protocol. It is composed of the lowest physical layer.

2 is a diagram illustrating the operation of each layer for data transmission generally used.

Referring to FIG. 2, the transmission layer of the transmitting end adds header information to a message payload received from an upper application layer to generate a new data unit. The transport layer sends it back to the lower network layer. In the network layer, a new data unit is generated by adding header information used in the network layer to data received from the transport layer, and then transmitted to the link layer, which is a lower layer. The link layer adds header information used in the link layer to data received from the upper layer to generate a new data unit, and transmits it to the lower layer physical layer. The physical layer transmits the data unit received from the link layer to the receiving end.

The physical layer of the receiving end receives the data unit from the transmitting end and transmits the data unit to its link layer, which is its upper layer. The receiver processes the header added for each layer and transmits the message payload from which the header is removed to the upper layer. Through this process, data transmission and reception between the transmitting side and the receiving end are performed.

As shown in FIG. 2, a protocol header is added at each layer to transmit and receive data between a transmitter and a receiver, thereby performing control functions such as data addressing, routing, forwarding, and data retransmission.

3 illustrates a protocol layer model defined in a wireless mobile communication system based on an IEEE 802.16 system.

Referring to FIG. 3, the MAC layer belonging to the link layer may consist of three sublayers. Service-Specific Convergence Sublayer (Service-Specific CS) is a MAC SDU (Service-specific MAC) of MAC Common Layer Sublayer (CPS) that receives data from external network received through CS SAP (Service Access Point). Can be transformed or mapped into Data Units. This layer may include a function of classifying SDUs of an external network and then associating a corresponding MAC Service Flow IDentifier (SFID) with a Connection IDentifier (CID).

Next, MAC CPS is a layer that provides the core functions of MAC such as system access, bandwidth allocation, connection establishment and management, and receives data classified by specific MAC connection from various CSs through MAC SAP. . In this case, quality of service (QoS) may be applied to data transmission and scheduling through the physical layer.

In addition, the security sublayer may provide authentication, security key exchange, and encryption functions.

In the above-described hierarchical structure, various methods may be used for the transmitting end to transmit data to the receiving end more reliably.

As an example of such a method, when a MAC SDU is delivered to a MAC CPS, the delivered MAC SDU may be divided into MAC PDUs within a range not exceeding the maximum transmission size supported by the MAC layer. Can be encrypted using Random Linear Code. This method is called Random Linear Coding (RLC).

A feature of the random linear encoding method is that each coded block may include information about all blocks included in the original block set. Therefore, even if some coded blocks are lost during transmission and reception, data can be quickly restored by receiving another coded block without having to receive the coded block again.

Coefficient matrix can be used for general random linear coding. Since coefficient matrix uses random number, it is not guaranteed to always generate decodable matrix.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an efficient communication method using random linear coding (RLC).

It is another object of the present invention to provide a coefficient matrix that is always decodable when a receiver receives a certain amount of packets without error.

Technical problems to be achieved in the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

In order to solve the above technical problem, the present invention provides a variety of methods for the transmitting end and the receiving end to transmit and receive data using random linear encoding.

In one aspect of the present invention, a method for transmitting data to a receiving end by applying a random linear coding (RLC) to a data block set including a plurality of data blocks generated by dividing higher layer data into a predetermined size is performed. Generating encoded blocks and transmitting the plurality of encoded blocks to the receiving end. The generating of the plurality of coded blocks may be performed by using a coefficient matrix having independent characteristics of each row in a preset Galois field. have.

In this case, the coefficient matrix may have a form such as matrix 1.

[Matrix 1]

는 상기 계수행렬을 나타내고, 제 1열을 구성하는 각 원소(v _i )는 상기 기 설정된 갈루아 필드에서 '1'을 제외하고 선택된 서로 다른 k개의 원소이며,

이고,

이며, m은 갈루아 필드의 크기를 결정하는 차수를 나타내는 것일 수 있다.From here,

Represents the coefficient matrix, and each element ( v _i ) constituting the first column is k different elements selected from the preset Galois field except for '1',

ego,

And m may represent an order for determining the size of the Galois field.

The method may further include sharing the elements v _i constituting the first column of the coefficient matrix by the transmitting end and the receiving end.

In addition, the sharing of each element may be performed through an initial network entry procedure of the transmitter and the receiver.

In addition, the plurality of coded blocks are transmitted to a receiving end through at least one protocol data unit (PDU) including a MAC header, wherein the MAC header is a field indicating whether the coded block is random linear encoding and the coded It may include at least one of the fields indicating the number of the block.

In addition, the plurality of encoded blocks are transmitted to a receiving end through one or more protocol data units (PDUs) including a predetermined subheader, and the predetermined subheader is a field indicating whether the encoded block is random linearly encoded. And a field indicating a number of the encoded block.

In another aspect of the present invention, a method of receiving data at a receiving end includes receiving a plurality of encoded blocks from the transmitting end and decoding the received plurality of encoded blocks using a first coefficient matrix. It may include the step. In this case, the first coefficient matrix is a coefficient matrix used in the process of generating the plurality of coded blocks by applying a random linear coding (RLC) to a predetermined number of original data blocks in the transmitting end, wherein each row is a preset Galois. It may be one having independent characteristics in a field (Galois field).

In this case, the decoding of the plurality of encoded blocks includes: a predetermined number of rows corresponding to each number of a predetermined number of encoded blocks received without error among the plurality of encoded blocks in the coefficient matrix. ) Generating a second coefficient matrix by generating the second coefficient matrix, generating an inverse of the second coefficient matrix, and using the generated inverse matrix and the predetermined number of encoded blocks received without error. Restoring the blocks.

In addition, the number of each of the predetermined number of encoded blocks may be estimated using the size of the encoded block determined by the preset Galois field.

Further, the plurality of coded blocks are received from the transmitting end through one or more protocol data units (PDUs) including a MAC header, and the MAC header is a random linear form of the plurality of coded blocks included in the protocol data unit. And a field indicating whether to encode, and the receiving end may further consider whether the random linear encoding is performed in estimating the number of each of the predetermined number of encoded blocks.

In addition, the plurality of encoded blocks may be received from the transmitting end through at least one protocol data unit (PDU) including a MAC header, and the MAC header may include a field indicating a number of the encoded block.

The generating of the second coefficient matrix may include: a number of a predetermined number of encoded blocks received without errors among the elements v _i constituting the shared first column of the coefficient matrix without errors. The method may include generating the predetermined number of rows by sequentially increasing the order of elements corresponding to each of the elements to satisfy the shape of the first coefficient matrix.

According to the present invention has the following effects.

First, according to the present invention, efficient communication can be performed by using random linear encoding.

Second, according to the present invention, since a coefficient matrix capable of decoding is always provided when a certain amount of packets are received without error, an efficient communication can be performed.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

The present invention relates to a wireless access system, and a communication method using random linear coding is disclosed.

The following embodiments are a combination of elements and features of the present invention in a predetermined form. Each component or feature may be considered to be optional unless otherwise stated. Each component or feature may be implemented in a form that is not combined with other components or features. In addition, some of the elements and / or features may be combined to form an embodiment of the present invention. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments.

In the present specification, embodiments of the present invention have been described based on data transmission / reception relations between a base station and a terminal. Here, the base station has a meaning as a terminal node of the network that directly communicates with the terminal. The specific operation described as performed by the base station in this document may be performed by an upper node of the base station in some cases.

That is, it is obvious that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. A 'base station' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point, and the like. In addition, the term "terminal" may be replaced with terms such as a user equipment (UE), a mobile station (MS), a mobile subscriber station (MSS), and the like.

Embodiments of the invention may be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

For a hardware implementation, the method according to embodiments of the present invention may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) , Field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of a module, procedure, or function that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

Specific terms used in the following description are provided to help the understanding of the present invention, and the use of such specific terms may be changed to other forms without departing from the technical spirit of the present invention.

4 illustrates a method of configuring a MAC PDU using a service data unit (SDU).

Referring to FIG. 4, a MAC PDU may be configured using a service data unit (SDU) received from a higher layer. In this case, fragmentation or packing techniques may be used. Fragmentation refers to the operation of dividing a PDU, which is the basic exchange unit of an SDU or protocol, into several smaller units. The packing technique combines several small fields into one large field, which means combining two or more information units into one physical unit in order to save storage space.

FIG. 5 is a diagram illustrating an example of a MAC PDU (MAC Protocol Data Unit) form defined in a wireless MAN mobile communication system based on the IEEE 802.16 system.

In general, in the link layer (that is, the link layer or the MAC layer) and the physical layer (layer below the second layer), a protocol according to each system such as LAN, Wireless LAN, 3GPP / 3GPP2 or Wireless MAN, and the header of the MAC PDU The format is defined differently. The MAC header includes a node MAC address or link address for data transfer between nodes in the link layer, and may include header error check and link layer control information.

5, each MAC PDU starts with a MAC header of a certain length. The header is located before the payload of the MAC PDU. The payload of a MAC PDU may be composed of a subheader, a MAC SDU, and a fragment. The length of payload information may be changed to represent a variable byte quantity. Accordingly, the MAC sublayer may transmit various traffic types of the upper layer without recognizing the format or bit pattern of the message. All reserved fields are set to '0' on transmission and ignored on reception.

The MAC PDU may include a cyclic redundancy check (CRC) for error detection. CRC function may be implemented in the physical layer of the OFDMA system. All fields reserved in the MAC PDU are designated as '0' and are ignored on receipt.

6 illustrates an example of a MAC header type used in a wireless MAN mobile communication system based on the IEEE 802.16 system.

Referring to FIG. 6, six subheaders may be used in a MAC PDU together with a general MAC header. Subheaders for each MAC PDU are inserted after the generic MAC header. Description of each field included in the MAC header will be described below.

The HT (Header Type) field indicates a header type and indicates whether the corresponding MAC PDU is a general MAC header including a payload behind the header or a signaling header for controlling a bandwidth request. The EC (Encryption Control) field indicates encryption control and indicates whether the payload is encrypted. The Type field indicates whether there is a subheader following the header and the type of subheader. The Extended Subheader Field (ESF) field indicates the presence or absence of an extended subheader after the header.

In addition, the CI (CRC Indication) field indicates whether the CRC is attached after the payload. The Encryption Key Sequence (EKS) field indicates an encryption key sequence number used for encryption when the payload is encrypted. The LEN (LENgth) field indicates the length of the MAC PDU. The Connection Identifier (CID) field indicates a connection identifier on which a MAC PDU is delivered. A connection is used as an identifier of a MAC layer for data and message transfer between a base station and a terminal, and the CID identifies a specific terminal or identifies a specific service between the base station and the terminal. The Header Check Sequence (HCS) is used to detect errors in the header. In FIG. 6, the number in parentheses after the name of each field indicates the number of bits occupied by each field.

In embodiments of the present invention, data may be encoded using a random linear coding (RLC) method. The random linear coding method is one of the block coding methods.

A feature of the random linear coding method is that each coded block may include information about all blocks included in an original block set. Therefore, even if some coded blocks are lost during transmission and reception, data can be quickly restored by receiving another coded block without having to receive the coded block again. The random linear encoding method is merely a term defining a data processing method exemplified in the present invention, and the term representing the method may be variously modified.

7 is a diagram illustrating a process of encoding data block sets using a random linear encoding method applicable to an embodiment of the present invention.

Referring to FIG. 7, original data represents service data units (SDUs) transmitted from higher layers of a transmitting end. The transmitting end may divide the original data (SDU) into PDUs within a range not exceeding the maximum transmission size supported by the MAC layer. Hereinafter, such a PDU is referred to herein as an original packet or an original block. The transmitting end may configure the block set (or segment) by grouping the divided original blocks by an arbitrary number n. Hereinafter, in the present specification, a block set generated by grouping original blocks in an arbitrary number is referred to as an “original block set” or an “original packet set”.

In this case, the number n of block sets may be determined by the channel environment of the communication network, performance information of the transmitter and receiver, requirements of the application program, and the like. In addition, the transmitting end may configure a total of k original block sets.

The transmitter generates a random coefficient or a random coefficient matrix c _ji for coding the divided data blocks. The transmitter may encode the divided data blocks using the random coefficient matrix c _ji generated according to a predetermined rule.

The transmitting end may perform encoding using a random linear encoding method in units of block sets (for example, for each of n selected blocks). In this case, the set of n encoded blocks may be referred to as an "encoded block set" or an "encoded packet set". The receiving end may perform decoding upon receiving the selected number n of encoded blocks. Hereinafter, the "coded block set" may be referred to as "code block set" and the "coded block" may be referred to as "code block".

Each code block generated by applying the random linear encoding method may include information about all blocks included in the original block set. Therefore, in order to recover a series of information blocks from the code blocks received at the receiving end, n coefficient blocks and random coefficients used when encoding each block of data are required.

The transmitting end generates new random coefficients until the receiving end completely decodes the data, generates code blocks, and sends them to the receiving end. In this case, n code blocks need not be delivered in the coded order, and each code block is independent.

)을 부호화하여 생성되는 코드블록 집합(

)을 생성하는 방법의 일례를 나타낸다.Equation 1 is the original block set (

Code block set generated by encoding

An example of the method of generating) is shown.

를 계수행렬이라 하고, 이는 원본 블록집합(

)을 조합하는 방법을 나타낸다. 계수행렬(

)을 생성하는 방법은 다음과 같다.In Equation 1

Is called the coefficient matrix, which is the original block set (

) Is combined. Coefficient matrix

) Is generated as follows.

)은 송신단 또는 송신단과 수신단이 일정 범위에서 결정한 난수(random number)를 이용하여 생성될 수 있다. 난수란, 송신단이 또는 송신단과 수신단이 협의를 통해 일정 범위(예를 들어, 0~255)의 수를 정하고, 상기 일정 범위의 수에서 무작위로 추출한 수를 말한다. 또한, 송신단 및 수신단은 랜덤계수를 생성하는데 필요한 시드(seed) 값을 공유하여 계수행렬(

)을 생성할 수도 있다. 이때, 계수행렬의 사이즈는 n×n으로 정의될 수 있다. Coefficient Matrix Used in Random Linear Coding Method

) May be generated using a random number determined by a transmitting end or a transmitting end and a receiving end in a predetermined range. The random number refers to a number that is determined by the transmitter or the receiver and the receiver by a predetermined number (for example, 0 to 255) by negotiation, and is randomly extracted from the number of the predetermined range. In addition, the transmitting end and the receiving end share a seed matrix required to generate a random coefficient,

You can also create). In this case, the size of the coefficient matrix may be defined as n × n.

Equation 2 shows Equation 1 as another expression method.

In Equation 2, a code block may be represented by coded-blk _j and a coefficient matrix may be represented by c _ji . In addition, the original block may be represented by blk _i .

When the transmitter transmits all n code blocks of the first code block set, and the receiver receives all n code blocks, the original block set may be restored. Thereafter, the transmitting end performs data communication by transmitting code blocks included in the next second block set.

In order to use a communication method using random linear coding (hereinafter, RLC), first, a size of a data block set, a size of a coded block, and a galoi field of a random coefficient (GF) are used. Galois Field). The Gallois field GF can be determined as follows. GF (2 ^ 2) can be used to compute two bits of symbols into two-bit symbols, and GF (2 ^ 8) can be used to compute eight bits of symbols into eight-bit symbols. Can give

When the size of the data block set and the size of the code block are determined, the number of coded blocks required for decoding may be determined. The transmitter may perform encoding by using random coefficients required for encoding according to a predetermined Galois field. The random coefficients may be transmitted together when transmitting the coded blocks. In addition, if the transmitting and receiving end generates the random coefficients in advance and the transmitting and receiving ends have information on the same random coefficients, the transmitting end may transmit only the index of the random coefficient used when encoding each code block to the receiving end. have. In the case of sequential data transmission in which a signal transmitted during communication does not disappear, the transceiver may sequentially encode and decode predetermined random coefficients.

)을 부호화하는데 사용한 계수행렬(

)의 역행렬(

)을 생성한 다음, 생성된 역행렬 및 수신된 코드블록 집합(

)을 이용한 연산을 통하여 원본 블록집합(

)을 복원할 수 있는 것이다. 이를 식으로 나타내면 아래 수학식 3과 같다.In other words, the receiving end has the original block set (

Coefficient matrix used to encode

Inverse of

), Then the generated inverse and received set of code blocks (

Original block set (

) Can be restored. This is expressed as Equation 3 below.

Coefficient Matrix to Ensure Decoding at the Receiver

Hereinafter, as a coefficient matrix proposed by the present invention, a coefficient matrix which can always be decoded when a sufficient number or more of a predetermined number of packets are received without error at the receiving end will be described.

First, it is assumed that a Galois field or finite field used for a random linear coding operation in the present embodiments is GF (2 ^ 8). This is because GF (2 ^ 8) can represent a number from 1 to 255, which makes byte operations easy. Of course, it is also possible to extend to other finite bodies using the same method.

The coefficient matrix used for coding and decoding in random linear coding has k (k≥n) output blocks using n input blocks (ie original blocks). When producing (ie coded blocks), a matrix of size k × n is needed. That is, in the operation of Equation 1, each matrix has a form as shown in Equation 4 below.

인 조건을 만족한다.In the matrices of Equation 4, when each element is i = k and j = n,

Satisfies the condition

행렬의 행(row)들 중에서 오류없이 수신한 e _i 값들에 해당하는 행들만을 뽑아서 디코딩을 수행한다. 예를 들어, e ₂ 가 오류없이 수신된 경우, 두 번째 행([h _2,1 h _2,2 ... h _2,n ])이 s ₂ 를 복원하기 위하여 선택되게 된다. 이러한 방법을 통하여 수신단은 선택된 행들 중에서 n개를 사용하여 n×n 크기의 행렬을 생성한 다음, 생성된 행렬의 역행렬(inversion)을 취하여 n 개의 원본 블럭에 대한 디코딩을 수행할 수 있다. 물론, 이러한 디코딩 과정은 오류없이 수신한 e _i 값들에 해당하는 행들을 먼저 생성한 후에 n 개를 선택할 수도 있지만, n개의 오류없는 e _i 들을 먼저 선택한 후 해당 n개의 행을 생성하는 순서로 수행될 수도 있다. When the receiver performs decoding,

Decoding is performed by extracting only rows corresponding to e _i values received without errors from the rows of the matrix. For example, if e ₂ is received without error, the second row ([ h _2,1 h _2,2 ... h _{2, n} ]) is selected to recover s ₂ . Through this method, the receiving end may generate an n × n matrix using n of the selected rows, and then decode the n original blocks by taking an inversion of the generated matrix. Of course, this decoding process may be performed after first generating rows corresponding to e _i values received without error, but selecting n error-free e _i first and then generating n rows. It may be.

행렬 중에서 어떠한 n개의 행을 선택하여 n×n 크기의 행렬을 생성하더라도 항상 역행렬을 취할 수 있어야 한다.

행렬이 이러한 조건을 만족하기 위해서는

행렬의 각 행이 갈루아 필드 또는 유한체 내에서 독립(independent)일 조건을 만족해야 한다.In order to always enable the above-described decoding method, Equation 4

It should always be possible to take an inverse even when selecting n rows of the matrix and generating an n × n matrix.

In order for a matrix to satisfy these conditions,

Each row of the matrix must satisfy the condition that it is independent within a Galois field or finite field.

행렬로서, 아래 수학식 5와 같은 행렬을 제안한다.Therefore, in the present invention, even if a matrix of n × n is generated by randomly selecting n rows, the inverse matrix can always be taken.

As a matrix, a matrix such as Equation 5 below is proposed.

에서 제 1 행을 구성하는 v _i 가 기 설정된 갈루아 필드에서 '1'을 제외하고 선택된 서로 다른 k개의 원소인 조건을 만족하면, 이러한

행렬은

인 어떠한 벡터에 대하여도 상술한 디코딩을 가능하게 한다. 즉, 수학식 5의

행렬은 n개의 행을 임의로 선택하여 n×n 크 기의 행렬을 생성하더라도 항상 역행렬을 취할 수 있다. 다만, 수학식 5 의 행렬은

이고,

인 조건 또한 만족하는 것이 바람직하다. 이는 n이

보다 크면, 즉,

이면 다시 1이 되고

이면 첫번째 행과 동일한 수가 되기 때문이다. Matrix like Equation 5

If v _i constituting the first row in satisfies the condition of k different elements selected except '1' in the preset Gallois field, then

Matrix is

This enables the decoding described above for any vector. That is, the equation (5)

A matrix can always take an inverse even if an arbitrary number of n rows is generated to produce an n × n matrix. However, the matrix of Equation 5

ego,

It is also desirable to satisfy the phosphorus condition. N is

Is greater than,

If it's 1 again

Because if it is the same number as the first row.

The decoding process of the receiver using the coefficient matrix as shown in Equation 5 will be described in more detail with reference to FIG. 8.

8 illustrates an example of a data transmission and reception process using random linear encoding in a transmitting end and a receiving end according to an embodiment of the present invention.

)을 생성한다(S101).First, the transmitting end uses an original block set including n original blocks using original data (ie SDU).

) Is generated (S101).

)을 상기 수학식 5와 같은 계수행렬(

)을 이용하여 k개의 부호화된 블록들을 생성한다(S102).The sender sets the original block set (

) Is the coefficient matrix (Equation 5)

K coded blocks are generated using (S102).

)을 생성하고,

를 수신단에 전송한다(S103).The transmitting end uses a set of blocks encoded using k coded blocks (

),

It is transmitted to the receiving end (S103).

In this case, if one block is assumed to be one PDU as described above, it can be seen that k PDUs are transmitted from the transmitting end to the receiving end. However, the present invention is not limited thereto, and a plurality of encoded blocks or packets may be included in one PDU and transmitted to the receiving end.

)을 송신단으로부터 수신한다(S104).The receiving end is encoded block set (

) Is received from the transmitting end (S104).

) 중에서 오류없이 수신된 n개의 부호화된 블록들을 선택한다. 이때, 오류없이 수신된 n개의 부호화된 블록들의 집합을 편의상

이라 표기한다(S105). The receiving end receives the received encoded block set (

) Selects n coded blocks received without error. At this time, a set of n coded blocks received without error for convenience

This is indicated (S105).

)에서 선택하여 n×n 크기의 디코딩을 위한 계수행렬(

)을 생성한다(S106).The receiver receives n rows corresponding to the numbers of each of the n coded blocks, as shown in Equation 5 above.

Coefficient matrix for decoding n × n

) Is generated (S106).

)의 역행렬(

)을 생성한다. 이는, 전술된 바와 같이 상기 수학식 5와 같은 계수행렬(

)로부터 생성되는 디코딩을 위한 계수행렬이 갈루아 필드에서 독립(independent)한 성격을 이용한 것이다(S107).The receiving end uses the coefficient matrix for decoding (

Inverse of

). As described above, the coefficient matrix (Equation 5)

The coefficient matrix for decoding is generated from the () using the independent nature of the Galois field (S107).

연산을 수행하여 n 개의 원본 블록들로 구성된 원본 블록집합(

)을 복원할 수 있다(S108).The receiving end

Performs an operation on the original blockset consisting of n original blocks (

) Can be restored (S108).

Therefore, according to the present invention, if only n or more coded packets among k coded packets are received without error at the receiving end, the entire original packet can be restored and efficient communication is possible. Also, since the coefficient matrix for decoding generated from the coefficient matrix provided in the present invention has an indepedent characteristic in the Galois field, it can always take an inverse matrix, so that the decoding of the entire received data into some packets received without error. This is guaranteed.

Method of sharing coefficient matrix between transmitter and receiver

행렬이 수신단에서 원본 블록집합의 인코딩에 사용되는 경우, 수신단이 부호화된 블록집합을 디코딩할 수 있도록 송신단과 수신단이

행렬을 공유하는 방법을 설명한다.Hereinafter, satisfying the above conditions

When a matrix is used at the receiving end for encoding the original blockset, the transmitting end and the receiving end may be able to decode the encoded blockset.

Describes how to share a matrix.

행렬에서 제 1열의 원소들인 v₁ 내지 v_k 사이의 값들은 송신단이 수신단에 데이터 패킷(e.g. 원본 블록집합 또는 부호화된 블록집합)을 전송하기 전에 미리 양측에 공유되어 있는 것이 바람직하다. 이를 위하여, 송신단을 기지국이라 가정하고 수신단을 이동 단말이라 가정할 때, v₁ 내지 v_k 사이의 값들은 초기 망 진입(initial network entry)절차 또는 기지국에서 브로드캐스트되는 시스템 정보를 포함하는, 다양한 유니캐스트 또는 브로드캐스트 방법을 통하여 단말에 전달될 수 있다.First, in the form of the equation (5) proposed in the present invention

The values between v ₁ to v _k, which are elements of the first column of the matrix, are preferably shared in both sides before the transmitting end transmits a data packet (eg, original block set or encoded block set) to the receiving end. To this end, assuming a transmitting end as a base station and a receiving end as a mobile terminal, values between v ₁ and v _k include various network information including an initial network entry procedure or system information broadcast from the base station. It may be delivered to the terminal through a cast or broadcast method.

Or, suppose that values between v ₁ and v _k are generated according to a certain rule, for example, a predetermined sequence or equation. At this time, it is preferable that predetermined sequences or equations for generating values between v ₁ and v _k are promised to each other in advance. Therefore, when the transmitting end informs the receiving end of any one of the values between v ₁ and v _k (ei seed value), the receiving end generates all v ₁ to v _k using the obtained one value to generate the first column of the coefficient matrix. I can complete it.

Through the above-described methods, the receiving end may configure one column of the coefficient matrix used for encoding the original block set at the transmitting end. As one column of the coefficient matrix is constructed, the remainder of the coefficient matrix can be completed by filling each column element by increasing the order from 1 to n.

However, in order to recover the original block s _j from the coded block e _i , the receiving end needs to know the i value, that is, the number of the coded block. This is because the receiver must know the value of i to know the value of v _i used for encoding. To this end, the method for the receiver to find the value of i is as follows.

First, a method in which the transmitting end notifies the i value directly to the receiving end may be used. To this end, the sending end of the header, _i e in the process of generating e _i encodes s _j: may include the value of i to (eg generic MAC header Generic MAC Header) or a sub-header. The i value may be included in the header or subheader in the form of a 'retransmission packet number i' field.

Secondly, the receiving end may calculate the i value without direct information from the transmitting end. As mentioned above, the size of e _i is determined by the setting of the Galois field. Using this, the transmitting end can know the size of e _i , and can divide the received data by the size unit of e _i in order to estimate i value. In this case, the receiving end may be able to distinguish whether the received data is an original block or an encoded block. To this end, when generating a data packet, the transmitting end preferably includes a field for distinguishing the original block from the encoded block in the header or subheader of the PDU.

As another embodiment of the present invention, a terminal and a base station (FBS, MBS) will be described as a transmitting end or a receiving end on which the above-described embodiments of the present invention can be performed.

The terminal may operate as a transmitter in uplink and operate as a receiver in downlink. In addition, the base station may operate as a receiver in the uplink, and may operate as a transmitter in the downlink. That is, the terminal and the base station may include a transmitter and a receiver for transmitting information or data.

The transmitter and receiver may include a processor, module, part, and / or means for carrying out the embodiments of the present invention. In particular, the transmitter and receiver may include a module (means) for encrypting the message, a module for interpreting the encrypted message, an antenna for transmitting and receiving the message, and the like.

The terminal used in the embodiments of the present invention may include a low power radio frequency (RF) / intermediate frequency (IF) module. In addition, the terminal is a controller function, a MAC (Medium Access Control) frame variable control function, a handover function, authentication and encryption function, data according to the controller function, service characteristics and propagation environment for performing the above-described embodiments of the present invention. Means, modules or parts for performing packet modulation and demodulation, high speed packet channel coding, and real-time modem control for transmission.

The base station may transmit data received from the upper layer to the terminal by wireless or wired. The base station may include a low power radio frequency (RF) / intermediate frequency (IF) module. In addition, the base station is a controller function for performing the above-described embodiments of the present invention, orthogonal frequency division multiple access (OFDMA) packet scheduling, time division duplex (TDD) packet scheduling and channel multiplexing function MAC frame variable control function according to service characteristics and propagation environment, high speed traffic real time control function, hand over function, authentication and encryption function, packet modulation and demodulation function for data transmission, high speed packet channel coding function and real time modem control Means, modules or parts for performing functions and the like.

The invention can be embodied in other specific forms without departing from the spirit and essential features of the invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention. In addition, the claims may be combined to form an embodiment by combining claims that do not have an explicit citation relationship or may be incorporated as new claims by post-application correction.

1 shows an example of a commonly used internet protocol stack.

2 shows the operation of each layer for data transmission generally used.

3 shows a hierarchical structure of a general IEEE 802.16 system.

4 illustrates a method of configuring a MAC PDU using a service data unit (SDU).

FIG. 5 illustrates an example of a MAC PDU (MAC Protocol Data Unit) type defined in a wireless MAN mobile communication system based on an IEEE 802.16 system.

6 illustrates an example of a MAC header type used in a wireless MAN mobile communication system based on a commonly used IEEE 802.16 system.

7 illustrates a process of encoding data block sets using random linear coding that can be applied to embodiments of the present invention.

8 illustrates an example of a data transmission and reception process using random linear encoding in a transmitting end and a receiving end according to an embodiment of the present invention.

Claims (14)

In the method of transmitting data to the receiving end Generating a plurality of encoded blocks by applying random linear coding (RLC) to a data block set including a plurality of data blocks generated by dividing higher layer data into a predetermined size; And Transmitting the plurality of encoded blocks to the receiving end; Generating the plurality of encoded blocks may include: A method of transmitting data, characterized in that each row is performed using a coefficient matrix having independent characteristics in a preset Galois field. The method of claim 1, The coefficient matrix has a form as shown in the following matrix 1. [Matrix 1]

From here,

Represents the coefficient matrix, and each element ( v _i ) constituting the first column is k different elements selected from the preset Galois field except for '1',

ego,

Where m represents the order that determines the size of the Galois field. 3. The method of claim 2, And sharing the elements v _i constituting the first column of the coefficient matrix by the transmitting end and the receiving end. The method of claim 3, wherein The step of sharing each element, And performing an initial network entry procedure of the transmitting end and the receiving end. The method of claim 3. The plurality of encoded blocks, Transmitted to the receiving end via one or more protocol data units (PDUs) including a MAC header, The MAC header, And at least one of a field indicating whether a random linear encoding of the encoded block and a field indicating a number of the encoded block. The method of claim 3, wherein The plurality of encoded blocks, Transmitted to the receiving end via one or more protocol data units (PDUs) including a predetermined subheader, The predetermined subheader is And at least one of a field indicating whether a random linear encoding of the encoded block and a field indicating a number of the encoded block. In the method for receiving data at the receiving end, Receiving a plurality of encoded blocks from the transmitting end; And Decoding the received plurality of encoded blocks using a first coefficient matrix; The first coefficient matrix, A coefficient matrix used in the process of generating the plurality of coded blocks by applying random linear coding (RLC) to a predetermined number of original data blocks at the transmitting end, wherein each row is independent in a preset Galois field. A data receiving method, characterized in that it has one characteristic. The method of claim 7, wherein And the first coefficient matrix has the same shape as matrix 1 below. [Matrix 1]

From here,

Represents the first coefficient matrix, and each element ( v _i ) constituting the first column is k different elements selected from the preset Galois field except for '1',

ego,

Where m represents the order that determines the size of the Galois field. The method of claim 8, And sharing, by the transmitting end and the receiving end, each element v _i constituting the first column of the coefficient matrix. The method of claim 9, Decoding the received plurality of encoded blocks, Generating a second coefficient matrix by selecting a predetermined number of rows corresponding to each of a number of a predetermined number of coded blocks received without an error among the plurality of coded blocks in the coefficient matrix; Generating an inverse of the second coefficient matrix; And Restoring the predetermined number of original blocks using the generated inverse and the predetermined number of encoded blocks received without error. The method of claim 10, The number of each of the predetermined number of encoded blocks is And estimating the size of the coded block determined by the preset Galois field. The method of claim 11, The plurality of encoded blocks, Received from the transmitting end via one or more protocol data units (PDUs) including a MAC header, The MAC header includes a field indicating whether or not random linear encoding of the plurality of encoded blocks included in the protocol data unit, And the receiving end further considers whether the random linear encoding is performed in estimating the number of each of the predetermined number of encoded blocks. The method of claim 10, The plurality of encoded blocks, Received from the transmitting end via one or more protocol data units (PDUs) including a MAC header, And the MAC header includes a field indicating a number of the encoded block. The method of claim 10, Generating the second coefficient matrix, The order of the elements corresponding to each of the numbers of the predetermined number of coded blocks received without error among the elements v _i constituting the first column of the shared coefficient matrix, received without error. Generating the predetermined number of rows by sequentially incrementing to satisfy a form of?.

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