Coding circuits, decoding circuits, coding methods, decoding methods, transmission devices, and optical transmission systems

摘要

PROBLEM TO BE SOLVED: To provide a coding circuit, a decoding circuit, a coding method, a decoding method, a transmission device, and an optical transmission system capable of reducing power consumption without lowering the noise yield strength. An encoding circuit allocates a symbol in a multi-valued modulation constellation according to the value of each bit string, and a value of a bit string other than the first bit string so that a symbol closer to the center is assigned more. A conversion unit to be converted, a first generation unit that generates a first error correction code from a bit string for each frame, and a second generation unit that generates a second error correction code from a second bit string in each period within a frame period. And the first insertion part that delays the first error correction code and inserts it into the first bit string of the subsequent frame, and the second bit string that delays the second error correction code and generates the second error correction code. It has a second insertion unit to be inserted into the first bit string in the period after the period of, and the conversion unit uses the delayed first and second error correction codes for the conversion of the second bit string. [Selection diagram] FIG. 13