KR100851974B1 - Apparatus for encoding information, apparatus for decoding information, method for encoding information and method for decoding information - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information encoding technique and an information decoding technique in a low density parity check code. The information encoding apparatus according to the present invention encodes an information bit string using a predetermined check matrix to generate a codeword. And a codeword data deletion unit for deleting data of a predetermined range among the data of the codeword and the generated codeword, wherein the predetermined parity check matrix is divided into the same number of partial matrixes as the row weight of the parity check matrix in the column direction. By having a row weight of 1, deterioration in performance can be suppressed while reducing the circuit scale.

Description

Information encoding apparatus, information decoding apparatus, information encoding method and information decoding method {Apparatus for encoding information, apparatus for decoding information, method for encoding information and method for decoding information}

1 shows a structure of a parity check matrix of a low density parity check code according to an embodiment of the present invention.

2 shows an example of puncturing application using a parity check matrix according to an embodiment of the present invention.

3 shows another example of puncturing application using a parity check matrix according to an embodiment of the present invention.

4 illustrates an example of puncturing application using a check matrix according to the prior art.

5 is a block diagram of an apparatus for processing a low density parity check code according to an embodiment of the present invention.

6 is a configuration diagram of an information encoding apparatus according to an embodiment of the present invention.

7 is a configuration diagram of an information decoding apparatus according to an embodiment of the present invention.

The present invention relates to an information encoding technique and an information decoding technique in a low density parity check code. In particular, an information encoding apparatus, an information decoding apparatus, an information encoding method, and an information decoding method of a low density parity check code that can correspond to a plurality of coding rates. It is about.

In recent years, the data transmission speed has been very high in mobile communication, wireless LAN, and the like. In these fields, the frequency of errors varies greatly depending on the condition of the transmission path. Therefore, for high speed transmission, it is necessary to perform efficient data transmission when the state of a transmission path changes. In the error correction technique, the error correction capability is changed when the coding rate is changed, so that the data can be efficiently transmitted by appropriately selecting a plurality of coding rates according to the transmission path conditions. In addition, researches on error correction techniques such as Low Density Parity Check Codes (LDPC) have been actively conducted. One such example is Japanese Laid-Open Patent Publication No. 2006-54575. Here, the low density parity check code refers to a linear code defined by a check matrix having a very small number of elements of "1" in the matrix.

Furthermore, it is required to realize a plurality of standards in one terminal, such as a terminal supporting dual modes of a cellular phone and a wireless LAN, and a reduction in circuit scale is required even for a low density parity check code circuit mounted in the terminal. . In the case of plural standards, the circuit scale can be reduced by responding in one low density parity check code circuit. In order to cope with various standards in one low density parity check code circuit, it is necessary to be able to cope with a plurality of coding rates and to have flexibility in length of information bits.

As a method of changing the coding rate of the low density parity check code in the coding technique and the decoding technique of the low density parity check code, a method of providing a plurality of coding circuits and decoding circuits corresponding to one coding rate and replacing them has been proposed. However, according to this method, there is a problem that the circuit scale becomes too large.

Further, by applying a puncturing technique used in a turbo code or the like to the low density parity check matrix, there is a method corresponding to a plurality of coding rates in one low density parity check code circuit. The puncturing technique is a technique of adjusting a coding rate by removing at least one bit from a generated codeword and transmitting the same. However, in the case where the puncturing technique is applied in this way, it is not necessary to include a plurality of circuits, but in terms of the circuit scale, the puncturing technique lowers the error correction capability. Therefore, even if the puncturing technique is applied, it is necessary to reduce the deterioration of the error correction capability.

In order to suppress such deterioration, there is a conventional random puncturing technique. However, the random puncturing technique requires a circuit that stores all of the random patterns, which is disadvantageous in terms of circuit scale. As described above, a method of puncturing a continuous range of codewords has been proposed in order to suppress an increase in a circuit for storing a random pattern required by a random puncturing technique. However, according to this method, it is not necessary to remember the random puncturing pattern, but the puncturing causes the row weights of the check matrix not to be the same, that is, the error correction ability deteriorates due to the large difference in the row weights of each row of the check matrix. have.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a technical problem to be solved by the present invention is to reduce the performance of performance due to the application of puncturing while reducing the circuit scale for a low density parity check code that can cope with a plurality of code rates. An information encoding apparatus, an information decoding apparatus, an information encoding method, and an information decoding method which can be suppressed are provided.

According to an aspect of the present invention, there is provided an information encoding apparatus comprising: an encoding unit generating a codeword by encoding an information bit string using a predetermined parity check matrix; And a codeword data deletion unit for deleting data of a predetermined range among the generated codeword data, wherein the predetermined parity check matrix is divided into a partial matrix equal to the number of partial weights of the row weight of the parity check matrix in a column direction. The row weight of is characterized in that 1.

Conventionally, the circuit scale was large because a plurality of circuits were provided to cope with a plurality of coding rates and these were replaced with each other. In addition, when one circuit is provided and punctured, performance deteriorates, so that the circuit scale and performance cannot be achieved. In this regard, according to the present invention, the row weights of the partial matrices constituting the check matrix are all 1, so that even if puncturing any continuous range, the same row weights can be maintained in the check matrix, thereby preventing performance deterioration. have. In addition, by setting the puncturing position in a continuous range, it is only necessary to store the start position and the end position or the start position and the puncturing bit number, or the end position and the puncturing bit number, and the puncturing pattern does not need to be stored. Can be reduced. As described above, according to the present invention, both circuit scale and performance can be achieved.

In Japanese Laid-Open Patent Publication No. 2006-54575, the check matrix is limited to an irregular check matrix rather than a regular check matrix. It is also punctured in descending order of heat weight. In this way, the row weights are not uniform and the error correction capability is degraded. Therefore, the present invention, which makes the row weight uniform, is advantageous in terms of error correction capability.

The information encoding apparatus may further include: a puncturing start position storage unit for storing a puncturing start position; And a puncturing end position storing unit storing a puncturing end position, wherein the codeword data deleting unit deletes data of the puncturing end position range from the puncturing start position among the generated codeword data. It can be characterized.

The information encoding apparatus may further include a data insertion unit for inserting 1 or 0 data into a predetermined range of an information bit string having a length less than the number of information bits defined by the predetermined check matrix, and the encoding unit may include the predetermined check matrix. It is possible to encode the information bit string after the data insertion by using.

The information encoding apparatus further includes: an information bit fixed start position storage section for storing an information bit fixed start position; And an information bit fixed end position storage section for storing an information bit fixed end position, wherein the data inserting section stores data of 1 or 0 in a range of the information bit fixed end position at the information bit fixed start position of the information bit string. It may be characterized by inserting.

The information encoding apparatus further includes a parity bit number storage unit for storing the number of parity bits defined by the parity check matrix, and the codeword data deleting unit includes the information bit fixed start position value among the data of the generated codeword. The data in the range specified by the sum of the information bit fixed end position value and the parity bit number may be deleted from the sum of the parity bit numbers.

The information encoding apparatus further includes: an information bit fixed start position storage section for storing an information bit fixed start position; An information bit fixed end position storage section for storing the information bit fixed end position; A puncturing start position storage section for storing a puncturing start position; A puncturing end position storage unit for storing the puncturing end position; And a parity bit number storage unit for storing the number of parity bits defined by the check matrix, wherein the data insertion unit has an information bit having a length less than the number of information bits defined by the predetermined check matrix in an information bit fixed mode. And a codeword data deleting unit inserts data of the puncturing end position range from the puncturing start position among the data of the generated codeword in the puncturing mode. A range designated by the sum of the information bit fixed end position value and the parity bit number from the sum of the information bit fixed start position value and the parity bit number among the data of the generated codeword in the information bit fixed mode; The data may be deleted.

According to another aspect of the present invention, there is provided an information decoding apparatus including: a data insertion unit for inserting predetermined data into a predetermined range of received data; And a decoding unit for decoding the received data after the data insertion using a predetermined check matrix, wherein the predetermined check matrix is divided into a number of partial matrixes in the column direction equal to the row weight of the check matrix, and the row weight of each partial matrix. Is characterized by being 1.

The information decoding apparatus further includes: a puncturing start position storage unit for storing the puncturing start position, wherein the predetermined data is zero data; And a puncturing end position storage section for storing a puncturing end position, wherein the data insertion section inserts the zero data into a range designated as the puncturing start position and the puncturing end position of the received data. It can be characterized.

The information decoding apparatus further includes: an information bit fixed start position storage section for storing the information bit fixed start position, wherein the predetermined data is the maximum value of the log likelihood ratio; An information bit fixed end position storage section for storing the information bit fixed end position; A parity bit number storage unit for storing the number of parity bits; And a fixed data deletion unit for deleting data in a range of the information bit fixed end position from the information bit fixed start position among data of the estimated information bit string output from the decoder, wherein the data insertion unit is configured to delete the data of the received data. The maximum number of logarithmic likelihood ratios may be inserted into a range specified by the sum of the information bit fixed start position value and the parity bit number and the sum of the information bit fixed end position value and the parity bit number. .

The information decoding apparatus further includes: an information bit fixed start position storage section for storing an information bit fixed start position; An information bit fixed end position storage section for storing the information bit fixed end position; A puncturing start position storage section for storing a puncturing start position; A puncturing end position storage unit for storing the puncturing end position; A parity bit number storage section for storing the parity bit number; And a fixed data deletion unit for deleting data in a range of the information bit fixed end position from the information bit fixed start position among data of the estimated information bit string output from the decoder in the information bit fixed mode. In the information bit lock mode, the maximum value of the log likelihood ratio is set in a range specified by the sum of the information bit lock end position value and the parity bit number from the sum of the information bit lock start position value and the parity bit number of the received data. And inserting 0 data into a range designated as the puncturing end position range from the puncturing start position of the received data in the puncturing mode.

According to another aspect of the present invention, there is provided a method of encoding an information, the method comprising: (a) generating a check matrix such that the row weight of each sub-matrix is equal to 1 when the sub-matrix is divided into the same number of sub-matrix in the column direction. ; (b) generating a codeword by encoding an information bit string using the check matrix; And (c) deleting data of a predetermined range of data of the generated codeword.

The information encoding method may further include storing a puncturing start position and a puncturing end position, and the step (c) may include the puncturing end position at the puncturing start position among data of the generated codeword. The data of the range may be deleted.

The information encoding method may further include inserting 1 or 0 data into a predetermined range of an information bit string having a length less than the number of information bits defined by the check matrix, and the step (b) may include the check matrix. It is possible to encode the information bit string after the data insertion by using.

The information encoding method may further include storing an information bit fixation start position and an information bit fixation end position, wherein the inserting is a range of the information bit fixation end position at the information bit fixation start position of the information bit string. It may be characterized by inserting the data of 1 or 0 into.

The information encoding method may further include storing the number of parity bits defined by the parity check matrix, and the step (c) includes the information bit fixed start position value and the parity bits in the generated codeword data. The data of the range specified by the sum of the information bit fixed end position value and the parity bit number may be deleted from the sum of the numbers.

According to another aspect of the present invention, there is provided a method of decoding an information, the method comprising: (a) generating a check matrix such that the row weight of each sub-matrix becomes 1 when the sub-matrix is divided into the same number of sub-matrix in the column direction. ; (b) inserting predetermined data into a predetermined range of the received data; And (c) decoding the received data after the data insertion using the test matrix.

The information decoding method may further include storing the puncturing start position and the puncturing end position, wherein the predetermined data is zero data, and the step (b) includes the puncturing start position and the puncturing position of the received data. The zero data may be inserted into a range designated as the puncturing end position.

The information decoding method may further include: storing an information bit fixing start position and an information bit fixing end position, wherein the predetermined data is a maximum value of a log likelihood ratio; Storing the number of parity bits; And deleting data of a range of the information bit fixed end position from the information bit fixed start position among data of the estimated information bit string generated by decoding the received data, wherein step (b) comprises: receiving the received data; And a maximum value of the logarithmic likelihood ratio is inserted into a range specified by the sum of the information bit fixed end position value and the parity bit number from the sum of the information bit fixed start position value and the number of parity bits. have.

In order to solve said another technical subject, the program for making a computer function as the above-mentioned information coding apparatus or information decoding apparatus which concerns on this invention, and the computer-readable recording medium which recorded the program are provided. Here, the program may be described by any programming language. As the recording medium, for example, a recording medium which is generally used as a recording medium for recording a program such as a CD-ROM, a DVD-ROM, a flexible disk, or any recording medium to be used in the future can be adopted.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in this specification and drawing, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol about the component which has substantially the same functional structure.

First, the structure of the parity check matrix which is a characteristic element in embodiment of this invention is demonstrated.

If a check matrix is required, the check matrix is determined in advance so as to have good characteristics by the method described below. When the coding rate is changed, successive ranges are punctured to simplify the device configuration. By using the check matrix constructed by the method shown below, even if the continuous range is punctured, the difference in the row weight value of each row of the check matrix after the code rate change is reduced. That is, the row weights are the same, and a check matrix can be constructed that can prevent performance degradation due to puncturing.

1 shows a structure of a parity check matrix of a low density parity check code according to an embodiment of the present invention.

Referring to FIG. 1, the parity check matrix according to the present embodiment is in the form of M rows and N columns, and partial matrixes obtained by dividing the parity check matrix by k in the column direction, that is, the transverse direction (H1,..., Hk in FIG. 1) are shown. It consists of). Where k is the same value as the row weight of the test matrix. For example, if the row weight is 6, the check matrix consists of 6 submatrices. The number of columns in each submatrix need not be constant, but in the case of regular check matrices, the number of columns in each submatrix is the same. In the case of an irregular check matrix, the number of columns of each sub-matrix is not the same.

Each submatrix is then constructed such that the row weights of each submatrix are all 1. Further, elements of "1" are randomly arranged in each partial matrix. In this way, the error correction capability is further improved by randomly arranging the elements of "1". By using the parity check matrix configuration according to the present embodiment without determining the bit positions to be punctured as in random puncturing, it is possible to easily determine a parity check matrix that suppresses deterioration of performance simply by puncturing a continuous range.

2 shows an example of puncturing application using a parity check matrix according to an embodiment of the present invention.

The size of the parity check matrix shown in FIG. 2 is 9 rows and 18 columns, and the size of each divided partial matrix is 9 rows and 3 columns. In the present embodiment, the number of columns of each partial matrix is three columns, but the number of columns of each partial matrix may be different. As shown in bold in Fig. 2, it is assumed that the continuous ranges (first row, second row, and third row) represented by Pn are punctured. Pn is equal to the number of columns of the puncturing partial matrix. However, the continuous range is not limited to the left end as shown in FIG. 2, but may be punctured in the fourth row, the fifth row, and the sixth row, for example. By constructing the parity check matrix as in the present embodiment, the row weights of each row after puncturing are all five, and there is no difference in the row weights of each row, and the same row weights are obtained.

3 shows another example of puncturing application using a parity check matrix according to an embodiment of the present invention.

3 shows an example in which the puncturing position and the puncturing bit number Pn are different from those in FIG. 2. In this example, Pn is 5, which is different from the column number 3 of the partial matrix. As indicated in bold in Fig. 3, the continuous ranges indicated by Pn are in the fourth row, the fifth row, the sixth row, the seventh row, and the eighth row. In the case of using the parity check matrix structure according to the present embodiment, even when the number of puncturing bits does not match the number of columns of the partial matrix, the row weight of each row after puncture is 4 or 5, and the difference in row weight is only 1. In the example shown in Fig. 3, the start position of puncturing is the first column of the partial matrix. Alternatively, the end position of the puncturing may be the final column of the partial matrix.

4 illustrates an example of puncturing application using a check matrix according to the prior art. In the prior art, elements of "1" are randomly arranged in the parity check matrix of 9 rows and 18 columns shown in FIG. In this example, the row weight of each row is set to 6. As shown in bold in Fig. 4, it is assumed that the continuous ranges (first row, second row, and third row) indicated by Pn are punctured. In this case, as shown in Fig. 4, the row weights of each row after puncturing are at most 6 and at least 3, and the difference in the row weights of each row is 3 (maximum 6-at least 3). In FIG. 3, the difference between the row weights is greater than one. In other words, by puncturing, the row weights of the parity check matrix are not equal.

On the other hand, when the check matrix configuration according to the present embodiment is used as shown in FIG. 2, the row weights of the rows of the check matrix after puncturing are the same, and as shown in FIG. 3, the number of puncturing bits is equal to the number of columns of the partial matrix. Even if they do not coincide, the difference between the maximum and the minimum of each row weight of the check matrix after puncturing is only 1, and the row weight of the check matrix can be considered to be the same.

Hereinafter, a low density parity check code processing apparatus corresponding to a plurality of coding rates will be described in detail.

5 is a block diagram of an apparatus for processing a low density parity check code according to an embodiment of the present invention. The low density parity check code processing apparatus according to the present embodiment is used in a communication apparatus such as, for example, a mobile phone or a personal digital (data) assistant (PDA). As shown in FIG. 5, the transmitter 100 and the receiver are shown. It consists of 200. The transmitter 100 shown in FIG. 5 is an example of an information encoding apparatus according to the present invention, and performs a process of encoding information acquired by a microphone, a camera, or the like. 5 is an example of an information decoding apparatus according to the present invention, and receives a signal transmitted from the transmitter 100 and performs a process of decoding the received information. Hereinafter, it demonstrates in order.

Referring to FIG. 5, the transmitter 100 includes a CPU 110 for controlling the entire transmission apparatus, a microphone 120 for converting voice into an electric signal, a camera 130 for converting an image into an electric signal, a voice signal or an image. A video / audio signal processing circuit 140 for processing a signal, a coding circuit 150 for encoding a signal processed audio signal or a video signal, a transmission circuit 160 for transmitting the encoded signal, and the like.

The CPU 110 manages setting information used for setting the encoding circuit 150, and the setting information storage unit 170 stores the setting information. The information encoding process and the setting information storage unit 170 by the encoding circuit 150 will be described later with reference to FIG. 6.

The receiver 200 includes a receiving circuit 210 for receiving a signal transmitted from the transmitter 100, a decoding circuit 220 for decoding the received signal, a CPU 230 for controlling the entire receiving apparatus, a decoded video signal or A video / audio signal processing circuit 240 for processing an audio signal, a speaker 250 for releasing the signal processed audio signal to the outside, a monitor 260 for displaying a signal processed video signal, and the like.

The CPU 230 manages setting information used for setting the decoding circuit 220, and the setting information storage unit 270 stores the setting information. The information decoding processing and the setting information storage unit 270 by the decoding circuit 220 will be described later with reference to FIG. 7.

Next, a method of changing a coding rate according to an embodiment of the present invention will be described. Using the result of detecting the error of the received data in the decoding circuit of the receiver or the result of detecting the error of the received data by a cyclic redundancy check (CRC) of a higher layer in the video / audio signal processing circuit. The CPU determines the line state.

First, the information bit fixing mode will be described. In the information bit fixing mode, the length of the input information bit string is less than the number of information bits defined by the check matrix, and the coding rate is adjusted by fixing the short part to 0 or 1. .

Next, the puncturing mode will be described. If it is determined that there are many errors and the line condition is bad, the error correction capability is increased by reducing the number of puncturing bits of the parity bits to lower the coding rate. On the contrary, when it is determined that the error is small and the line state is good, the number of puncturing bits of the parity bits is increased to increase the coding rate, thereby improving the data transmission capability. At this time, the coding rate is adaptively determined according to the detected error frequency among the coding rates prepared in advance. Further, the puncturing position obtained by simulation or the like is selected so as to increase the error correction capability with respect to the determined coding rate, and the setting information is corrected. In addition, the code rate coincides with the transmitter by transmitting the determined coding rate to the transmitter. The coding rate Rp is calculated as Rp = In / (N-Pn), where N is the length of a codeword, In is the number of information bits, and Pn is the number of puncturing bits of the parity bits.

6 is a configuration diagram of an information encoding apparatus according to an embodiment of the present invention, and includes a CPU 110, an encoding circuit 150, and a setting information storage unit 170.

The encoding circuit 150 according to the present embodiment includes a data insertion unit 151, an encoding unit 155, and a codeword data deleting unit 156.

The data insertion unit 151 switches between selecting an information bit of an input information bit string or a predetermined fixed value of 0 or 1 based on the setting information set by the CPU 110. By selecting and inserting the fixed values in this way, the length of the information bit string is extended to the length before the coding rate change. To this end, the data insertion unit 151 receives the setting information from the setting information storage unit 170 to control the data insertion unit 151, a memory unit 153 for temporarily storing information bits, and And a selection unit 154 for switching between selecting an information bit or a predetermined fixed value of 0 or 1.

The setting information storage unit 170 includes an information bit fixed mode storage unit 171, an information bit fixed start position (SIn) storage unit 172, and an information bit fixed end position (EIn) storage unit 173. . The setting information storage unit 170 further includes a puncturing mode storage unit 174, a parity bit number Pty storage unit 175, a puncturing start position (SPn) storage unit 176, and a puncturing end position (EPn). The storage unit 177 is included. These storage units may be registers, and any form having a function capable of storing and retaining information is within the scope of the present invention. Here, the information bit fixing start position is a position at which data to be inserted into the information bit string starts in the information bit fixing mode, and the information bit fixing end position is a position at which the data to be inserted ends. The puncturing start position is a position at which data to be deleted from the codeword starts in the puncturing mode, and the puncturing end position is a position at which the data to be deleted ends.

The data insertion unit 151 selects the information bits from the information bit string that is always input when the information bit fixing mode is not used. However, in the information bit fixing mode, the data inserting unit 151 selects a fixed value of 0 or 1 in the range of SIn to EIn, and selects the information bit in other ranges.

In addition, as shown in FIG. 6, the encoding circuit 150 includes an encoding unit 155 at a rear end of the data insertion unit 151. The encoder 155 is a circuit for encoding the low density parity check code based on the check matrix before puncturing. The encoder 155 generates a code word using the check matrix on the information bit string output from the data inserter 151.

In addition, the encoding circuit 150 includes a codeword data deleting unit 156 at the rear end of the encoding unit 155, as shown in FIG. The codeword data deleting unit 156 functions to puncture a specified range of codewords. In the information bit fixed mode, the codeword data deleting unit 156 deletes data in the range designated by (Pty + SIn) and (Pty + EIn) from the codeword output from the encoding unit 155. In the puncturing mode, the codeword data deleting unit 156 deletes data in the range designated by SPn and EPn from the codeword output from the encoding unit 155. The codeword data deletion unit 156 then outputs this to the transmission circuit 160 as transmission data. The erasing method may be implemented by not reading data in a range that should be deleted when data received from the encoder 155 is accumulated and read in the memory 158 once.

7 is a configuration diagram of an information decoding apparatus according to an embodiment of the present invention, and includes a CPU 230, a decoding circuit 220, and a setting information storage unit 270.

The decoding circuit 220 according to the present embodiment includes a data inserting unit 221, a decoding unit 225, and a fixed data deleting unit 226.

The data insertion unit 221 selects whether to select the received data, the zero value, or the maximum value LLRmax of the log likelihood ratio based on the setting information set by the CPU 230. To this end, the data insertion unit 221 receives the setting information from the setting information storage unit 270 to control the data insertion unit 221, the memory unit 223 temporarily storing the received data, and the reception unit. And a selection unit 224 for switching between selecting data, zero, or selecting the maximum value LLRmax of the log likelihood ratio.

Here, the maximum value of the log likelihood ratio is demonstrated. In general, the punctured bits of the codeword are depunctured by inserting zero, assuming that the probability of " 0 " and " 1 " In the information bit fixed mode, on the other hand, since the transmitter already knows the value to insert into the information bit, the probability of "0" or "1" can be 100%. Therefore, when "0" is inserted into the information bit in the transmitter encoding circuit, the logarithm likelihood ratio with the probability of "0" is inserted and "1" is inserted in the transmitter encoding circuit. Insert a log likelihood ratio with 100% probability.

The setting information storage unit 270 includes an information bit fixed mode storage unit 271, an information bit fixed start position (SIn) storage unit 272, and an information bit fixed end position (EIn) storage unit 273. The setting information storage unit 270 further includes a puncturing mode storage unit 274, a parity bit number Pty storage unit 275, a puncturing start position (SPn) storage unit 276, and a puncturing end position (EPn). A storage unit 277 is included. These storage units may be registers, and any form having a function capable of storing and retaining information is within the scope of the present invention.

The data insertion unit 221 restores the received data to the length before puncturing by selecting and inserting a zero value or a maximum value LLRmax of the log likelihood ratio for the received data. In more detail, the selector 224 selects the maximum value of the logarithmic likelihood ratio in the range of (Pty + SIn) to (Pty + EIn) in the information bit fixed mode under the control of the controller 222. In the puncturing mode, the value 0 is selected in the range of SPn to EPn. Otherwise, the received data is always selected. The data insertion unit 221 inserts a zero value or a maximum likelihood ratio of the received data as described above. The data insertion unit 221 stores the received data once in the memory unit 223 and does not read out the received data from the memory unit 223 when the zero value or the maximum likelihood ratio is inserted. Perform.

In addition, the decoding circuit 220 includes a decoding unit 225 at the rear end of the data insertion unit 221 as shown in FIG. The decoding unit 225 performs a function of decoding the low density parity check code based on the parity check matrix before puncturing. The decoder 225 decodes the received data using a sum-product algorithm or the like and outputs an estimated information bit string. In addition, the decoding unit 225 terminates the repetition operation a predetermined number of times, or terminates the operation if the parity check is correct. However, if the parity check is not correct, error information is output. This error information is used to interpret the transmission line condition and set an appropriate coding rate. This series of processing is performed by the CPU 230 shown in FIG. 5, for example.

In addition, the decoding circuit 220 includes a fixed data deleting unit 226 at the rear end of the decoding unit 225 as shown in FIG. The fixed data deletion unit 226 deletes data in the range of EIn from SIn of the estimated information bit string output from the decoder in the case of the information bit fixed mode, and outputs the estimated information bit string after deletion as the original estimated information bit string. do. On the other hand, the fixed data erasing unit 226 outputs the estimated information bit string output from the decoding unit as the estimated information bit string as it is in the information bit fixing mode. The erasing method can be implemented by accumulating the data received from the decoding unit 225 into the memory unit 227 once, and not reading out the data of the range to be deleted when reading.

In the above, the transmitter 100 (an example of the information coding apparatus of this invention) and the receiver 200 (an example of the information decoding apparatus of this invention) which concern on embodiment of this invention were demonstrated. The transmitter 100 and the receiver 200 can make a computer function as the transmitter 100 or the receiver 200 by organizing a computer program for realizing the function in the computer. Such computer programs are distributed to the market in the form of recordings on predetermined recording media (for example, magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, etc.) or in the form of downloads via electronic networks. It is possible to let.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

For example, in the above embodiments, the receiver 100 (information encoding apparatus) and the transmitter 200 (information decoding apparatus) have been described in the case where they can correspond to both modes of the information bit fixing mode and the puncturing mode, respectively. The present invention is not limited to this. For example, the device configuration may correspond to only the information bit fixing mode, or the device configuration may correspond to only the puncturing mode. In this case, the setting information storage unit 170 shown in FIG. 6 and the setting information storage unit 270 shown in FIG. 7 need only include a storage unit necessary for either mode setting.

According to the present invention, by dividing the check matrix into the same number of partial matrixes as the column weights in the column direction, the row weight of each sub-matrix is equal to 1, so that even if puncturing any continuous range, the same row weights are used in the test matrix. Can be maintained and performance deterioration can be prevented. In addition, by setting the puncturing positions in a continuous range, it is not necessary to remember all the puncturing patterns, thereby reducing the circuit size. As described above, according to the present invention, deterioration in performance can be suppressed while reducing the circuit scale.

Claims (18)

An encoder for generating a codeword by encoding an information bit string using a predetermined parity check matrix; And A codeword data deletion unit for deleting data of a predetermined range among data of the generated codeword, And dividing the predetermined parity check matrix into the same number of partial matrixes as the row weights of the parity check matrix, and the row weight of each sub-matrix being one. The method of claim 1, A puncturing start position storage section for storing a puncturing start position; And Further comprising a puncturing end position storage unit for storing the puncturing end position, And the codeword data deleting unit deletes data of the puncturing end position range from the puncturing start position among the generated codeword data. The method of claim 1, And a data insertion unit for inserting 1 or 0 data into a predetermined range of the information bit string having a length less than the number of information bits defined by the predetermined check matrix. And the encoding unit encodes the information bit string after the data insertion using the predetermined parity check matrix. The method of claim 3, An information bit fixed start position storage section for storing the information bit fixed start position; And An information bit fixed end position storage section for storing the information bit fixed end position; And the data insertion unit inserts data of 1 or 0 in a range of the information bit fixing end position from the information bit fixing start position of the information bit string. The method of claim 4, wherein A parity bit number storage section for storing the number of parity bits defined by the check matrix; The codeword data deleting unit selects data in a range specified from the sum of the information bit fixed start position value and the parity bit number among the generated codeword data as the sum of the information bit fixed end position value and the parity bit number. And an information encoding apparatus. The method of claim 3, An information bit fixed start position storage section for storing the information bit fixed start position; An information bit fixed end position storage section for storing the information bit fixed end position; A puncturing start position storage section for storing a puncturing start position; A puncturing end position storage unit for storing the puncturing end position; And A parity bit number storage section for storing the number of parity bits defined by the check matrix; The data inserting unit inserts data of 1 or 0 in a predetermined range of an information bit string having a length less than the number of information bits defined by the predetermined check matrix in the information bit fixing mode. The codeword data deleting unit deletes the data of the puncturing end position range from the puncturing start position among the data of the codeword generated in the puncturing mode, and the data of the generated codeword in the information bit fixing mode. And data in a range specified by the sum of the information bit fixed end position value and the parity bit number from the sum of the information bit fixed start position value and the parity bit number. A data insertion unit for inserting predetermined data into a predetermined range of the received data; And A decoder which decodes the received data after the data insertion using a predetermined parity check matrix, And dividing the predetermined parity check matrix into the same number of partial matrixes as the row weights of the parity check matrix and the row weight of each sub-matrix is one. The method of claim 7, wherein The predetermined data is zero data, A puncturing start position storage section for storing a puncturing start position; And Further comprising a puncturing end position storage unit for storing the puncturing end position, And the data insertion unit inserts the data of 0 in a range designated by the puncturing start position and the puncturing end position of the received data. The method of claim 7, wherein The predetermined data is the maximum value of the log likelihood ratio, An information bit fixed start position storage section for storing the information bit fixed start position; An information bit fixed end position storage section for storing the information bit fixed end position; A parity bit number storage section for storing the parity bit number; And A fixed data deletion unit for deleting data in the range of the information bit fixed end position from the information bit fixed start position among data of the estimated information bit string output from the decoder, The data insertion unit sets the maximum likelihood ratio of the logarithmic likelihood ratio within a range specified by the sum of the information bit fixed end position value and the parity bit number from the sum of the information bit fixed start position value and the parity bit number of the received data. An information decoding device, characterized in that inserted. The method of claim 7, wherein An information bit fixed start position storage section for storing the information bit fixed start position; An information bit fixed end position storage section for storing the information bit fixed end position; A puncturing start position storage section for storing a puncturing start position; A puncturing end position storage unit for storing the puncturing end position; A parity bit number storage section for storing the parity bit number; And A fixed data deletion unit for deleting data in the range of the information bit fixed end position from the information bit fixed start position among data of the estimated information bit string output from the decoder in the information bit fixed mode; The data insertion unit has a log likelihood ratio in a range specified by the sum of the information bit fixed end position value and the parity bit number from the sum of the information bit fixed start position value and the parity bit number of the received data in the information bit fixed mode. And inserting a maximum value of 0 and inserting 0 data into a range designated as the puncturing end position range from the puncturing start position of the received data in the puncturing mode. (a) dividing the check matrix into the same number of submatrices as the row weights in the column direction and generating the check matrix such that the row weight of each sub-matrix is equal to 1; (b) generating a codeword by encoding an information bit string using the check matrix; And and (c) deleting data of a predetermined range of data of the generated codeword. The method of claim 11, Storing the puncturing start position and the puncturing end position; In the step (c), the data of the puncturing end position range is deleted from the puncturing start position among the generated codeword data. The method of claim 11, Inserting 1 or 0 data into a predetermined range of an information bit string having a length less than the number of information bits defined by the check matrix; In the step (b), the information bit stream after the data insertion is encoded using the parity check matrix. The method of claim 13, Storing the information bit fixation start position and the information bit fixation end position; And the inserting step inserts data of 1 or 0 in a range of the information bit fixing end position from the information bit fixing start position of the information bit string. The method of claim 14, Storing the number of parity bits defined by the check matrix; In the step (c), the data in the range of the information code fixed end position value and the parity bit number is specified from the sum of the information bit fixed start position value and the parity bit number among the generated codeword data. And an information encoding method. (a) dividing the check matrix into the same number of submatrices as the row weights in the column direction and generating the check matrix such that the row weight of each sub-matrix is equal to 1; (b) inserting predetermined data into a predetermined range of the received data; And and (c) decoding the received data after the data insertion using the parity check matrix. The method of claim 16, The predetermined data is zero data, Storing the puncturing start position and the puncturing end position; And the step (b) inserts the zero data into a range designated by the puncturing start position and the puncturing end position of the received data. The method of claim 16, The predetermined data is the maximum value of the log likelihood ratio, Storing an information bit fixation start position and an information bit fixation end position; Storing the number of parity bits; And Deleting data in the range of the information bit fixed end position from the information bit fixed start position among data of the estimated information bit string generated by decoding the received data; In the step (b), the maximum likelihood ratio of the logarithmic ratio is set within a range specified by the sum of the information bit fixed end position value and the parity bit number of the received data and the number of parity bits. An information decoding method comprising inserting a value.

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