Decoding circuit, decoding method and computer program

A decoding method used for coherent digital signal processing, the decoding method comprising:

• distributing, by a distributor, a decoding metric obtained by demodulating transmission data transmitted from a transmission device to each of a plurality of lanes on the basis of information on noise generated in a communication channel and a received signal;
• calculating, by a first likelihood calculation circuit that is provided in one of the plurality of lanes, a first logarithmic likelihood ratio using the distributed decoding metric;
• performing, by a decoder, error correction decoding using the first logarithmic likelihood ratio and acquiring an error-corrected code word;
• calculating, by one or more second likelihood calculation circuits that are provided in a lane different from the lane in which the first likelihood calculation circuit is provided among the plurality of lanes, one or more second logarithmic likelihood ratios on the basis of the decoding metric distributed by the distributor and the acquired error-corrected code word, and performing hard decision;
• combining, by a combiner, an output of the decoder and an output of the one or more second likelihood calculation circuit.

A non-transitory storage medium that stores a program for making a computer perform processes, the processes comprising:

• distributing a decoding metric obtained by demodulating transmission data transmitted from a transmission device to each of a plurality of lanes on the basis of information on noise generated in a communication channel and a received signal;
• calculating a first logarithmic likelihood ratio using the distributed decoding metric;
• performing error correction decoding using the first logarithmic likelihood ratio and acquiring an error-corrected code word;
• calculating one or more second logarithmic likelihood ratios on the basis of the distributed decoding metric and the acquired error-corrected code word, and performing hard decision;
• combining the acquired error-corrected code word with the calculated one or more second logarithmic likelihood ratios.