Abstract: A transmitter for transmitting a transmission signal subjected to modulation after error correction coding and a receiver including a phase compensation unit for receiving the transmission signal and performing demodulation therefor while maintaining synchronization thereof and an error correction decoding unit for performing decoding processing for received data that has been subjected to the demodulation. The transmitter transmits a signal formed of a plurality of pilot sequences as a part of the transmission signal, and the receiver has a phase slip estimation processing function for estimating the phase slip by the phase compensation unit by using the plurality of pilot sequences, and for estimating a phase difference component by the error correction decoding unit, to thereby correct a phase of the received data.

Abstract: A two-reference-point-pair determining unit 101 determines two reference point pairs by selecting two transmission symbol points with their LLR computation target bit being 0 and two transmission symbol points with their LLR computation target bit being 1. An LLR computation unit 113 assigns weights to the two LLRs calculated for the two reference point pairs, respectively, followed by adding them, and further adds to the addition result a correction term that may be zero sometimes, thus computing LLR for the two reference point pairs.

Abstract: A data structure of a check matrix for the error correction code is a data structure of a check matrix for an error correction code, in which the error correction code is the LDPC code, and in which the check matrix has a matrix structure in which rows are rearranged for submatrices consisting of a part of columns of the check matrix. Moreover, in the method and device for varying the coding rate of the error correction code, a puncture position that is determined in accordance with a puncture position determination signal is a puncture position with which a number of columns in which two or more 1s are contained in a region of the check matrix that is directly affected by puncturing is minimized.

Abstract: An input bit error ratio estimating method executed by a communication control unit includes a computing, a condition determining, a first input BER estimating, a second input BER estimating, a third input BER estimating, and an input BER estimation result outputting. In the condition determining, the communication control unit determines which of a plurality of conditions set in advance to be narrowed down to one has been established, based on a post-internal decoding residual error detection ratio. Based on the condition that is determined in the condition determining as one that has been established, the communication control unit selects one out of a plurality of processing procedures for estimating the input BER, namely, selects one of the first input BER estimating to the third input BER estimating and executes the selected processing.

Abstract: A transmitter for transmitting a transmission signal subjected to modulation after error correction coding and a receiver including a phase compensation unit for receiving the transmission signal and performing demodulation therefor while maintaining synchronization thereof and an error correction decoding unit for performing decoding processing for received data that has been subjected to the demodulation. The transmitter transmits a signal formed of a plurality of pilot sequences as a part of the transmission signal, and the receiver has a phase slip estimation processing function for estimating the phase slip by the phase compensation unit by using the plurality of pilot sequences, and for estimating a phase difference component by the error correction decoding unit, to thereby correct a phase of the received data.

Abstract: An error correction encoding device 1 includes a sparse matrix computing unit 2 that computes exclusive OR of a submatrix, in a parity-check matrix, corresponding to an information bit sequence, and the information bit sequence on the basis of the position of 1 in the submatrix to calculate a vector, a fundamental matrix operator 3 that calculates a predetermined matrix by performing a predetermined fundamental matrix operation on a submatrix, in the parity-check matrix, corresponding to a parity bit sequence, and a matrix multiplier 4 that calculates the parity bit sequence by multiplying the predetermined matrix which the fundamental matrix operator 3 calculates, and the vector which the sparse matrix computing unit 2 calculates.

Abstract: A Sum-product decoder 17 carries out soft-decision iterative decoding on a received signal s?(t) received by a signal receiving unit 12 by using an extended check matrix Hd which is a combination of a matrix D in which differential modulation by a differential modulator 3 is replaced by a check matrix and a check matrix H for error correcting codes to carry out error correction decoding on an information sequence bi.

Abstract: A two-reference-point-pair determining unit 101 determines two reference point pairs by selecting two transmission symbol points with their LLR computation target bit being 0 and two transmission symbol points with their LLR computation target bit being 1. An LLR computation unit 113 assigns weights to the two LLRs calculated for the two reference point pairs, respectively, followed by adding them, and further adds to the addition result a correction term that may be zero sometimes, thus computing LLR for the two reference point pairs.

Abstract: An error correction method and device and a communication system using them, including an LDPC code generation method capable of adjusting an encoding rate of an LDPC code in a variable manner while leaving the length of the code constant by use of an efficient encoding method or mechanism supporting a variable encoding rate, so that the encoding rate of the LDPC code can be adjusted without changing the code length. An error correction method includes a row dividing to divide each of a part or all of rows into two or more rows based on one parity check matrix, and a code construction to construct a plurality of LDPC codes with arbitrary code rates, respectively.

Abstract: In row calculation, a value which is obtained by subtracting an offset according to a minimum of the absolute values of column LLRs from the minimum of the absolute values of the column LLRs is set as a row LLR corresponding to a column of the column LLRs.

Abstract: An input bit error ratio estimating method executed by a communication control unit includes a computing, a condition determining, a first input BER estimating, a second input BER estimating, a third input BER estimating, and an input BER estimation result outputting. In the condition determining, the communication control unit determines which of a plurality of conditions set in advance to be narrowed down to one has been established, based on a post-internal decoding residual error detection ratio. Based on the condition that is determined in the condition determining as one that has been established, the communication control unit selects one out of a plurality of processing procedures for estimating the input BER, namely, selects one of the first input BER estimating to the third input BER estimating and executes the selected processing.

Abstract: An error correction method and device and a communication system using them, including an LDPC code generation method capable of adjusting an encoding rate of an LDPC code in a variable manner while leaving the length of the code constant by use of an efficient encoding method or mechanism supporting a variable encoding rate, so that the encoding rate of the LDPC code can be adjusted without changing the code length. An error correction method includes a row dividing to divide each of a part or all of rows into two or more rows based on one parity check matrix, and a code construction to construct a plurality of LDPC codes with arbitrary code rates, respectively.

Abstract: In row calculation, a value which is obtained by subtracting an offset according to a minimum of the absolute values of column LLRs from the minimum of the absolute values of the column LLRs is set as a row LLR corresponding to a column of the column LLRs.