A coding modulation method,
demodulation and decoding method and device for a
passive optical network are applied to the technical field of passive optical networks, and the coding modulation method comprises the following steps: carrying out
system polarization coding on a received first
data stream to obtain a second
data stream with an information bit and a frozen bit; according to a preset many-to-one mapping rule, mapping the second
data stream to a symbol set to obtain a mapped symbol
stream; and adjusting the sending probability of each symbol in the symbol
stream through truncation probability shaping in a preset format to obtain a modulated modulation
signal. According to the invention, the coding modulation of the data is carried out by combining the
system polarization coding technology, the many-to-one mapping technology and the truncation probability shaping technology, so that the data can be obtained through simple
inverse operation, the introduction of a distribution matcher to realize probability shaping is avoided, the complexity source is reduced, and the
data processing efficiency is improved. And meanwhile, the
algorithm complexity is greatly reduced compared with the
algorithm which needs to be subjected to iterative de-mapping and decoding.