Abstract: There is provided an encoding circuit used for coherent digital signal processing, including: a serial-parallel circuit that divides input data into a plurality of pieces of divided data by serial-parallel conversion; a plurality of encoders that adds an error correction code to the divided data and encodes the divided data; and a bit conversion circuit that converts a bit sequence in order to make an amount of noise generated by a communication channel non-uniform among the plurality of pieces of divided data encoded by each of the plurality of encoders.

Abstract: A communication device includes an amplitude conversion unit configured to generate a symbol sequence according to a bit sequence, a distribution matching unit configured to add redundant bits to the symbol sequence through probabilistic amplitude shaping (PAS) coding, an insertion unit configured to insert a pilot symbol into the symbol sequence to which the redundant bits have been added and transmit the symbol sequence into which the pilot symbol has been inserted to a transmission path, and a control unit configured to acquire information on the transmission path and change, according to the information on the transmission path, allocation of the redundancy of the PAS coding and the redundancy of the pilot symbol in a range of redundancy that is able to be allocated depending on a predetermined throughput.

Abstract: An aspect of the present invention is a communication system including: an encoding unit configured to transform an input symbol sequence into an output symbol sequence, the input symbol sequence being a sequence of first symbols, the output symbol sequence being a sequence of second symbols; and a decoding unit configured to transform the output symbol sequence into the input symbol sequence in accordance with a decoding-side transformation mapping for transforming the output symbol sequence into the input symbol sequence that is a transformation source for the output symbol sequence, wherein the encoding unit transforms the input symbol sequence into the output symbol sequence in accordance with encoding-side transformation destination candidate information, the input symbol sequence, and a transformation probability, the encoding-side transformation destination candidate information being information indicating candidates of a transformation destination for the input symbol sequence, the transformation pro

Abstract: A communication device includes an amplitude conversion unit configured to generate a symbol sequence according to a bit sequence, a distribution matching unit configured to add redundant bits to the symbol sequence through probabilistic amplitude shaping (PAS) coding, an insertion unit configured to insert a pilot symbol into the symbol sequence to which the redundant bits have been added and transmit the symbol sequence into which the pilot symbol has been inserted to a transmission path, and a control unit configured to acquire information on the transmission path and change, according to the information on the transmission path, allocation of the redundancy of the PAS coding and the redundancy of the pilot symbol in a range of redundancy that is able to be allocated depending on a predetermined throughput.