US Patent 7434135 Decoder and method for decoding low-density parity-check code

When received data is decoded, a CPU stores a value “1”, which is included in a vector obtained by multiplying the received data by a parity check matrix, as the number of parity errors and also stores hard-decision result information corresponding to the number of parity errors in an output candidate information storage area. If the CPU determines that the received data is uncorrectable after the received data is decoded a given number of times, it reads hard-decision result information corresponding to the smallest number of parity errors, which are included in the number of parity errors stored in the output candidate information storage area and outputs it as a decoding result.