The present disclosure provides example communication methods and example communication apparatuses for non-coherent transmission. One example communication method includes determining Pi first symbols based on a first to-be-modulated bit, where P.sub.1=M×N.sub.1, N.sub.1 is a quantity of resource units used to carry the P.sub.1 first symbols, M is a positive integer, and N.sub.1 is an integer greater than 1. P.sub.2 second symbols are determined based on a second to-be-modulated bit, where P.sub.2=M×N.sub.2, and N.sub.2 is an integer greater than 1. P.sub.3 third symbols are determined based on the P.sub.1 first symbols and the P.sub.2 second symbols, where P.sub.3=M×N.sub.3, N.sub.3 is a quantity of resource units used to carry the P.sub.3 third symbols, and N.sub.3 is less than or equal to N.sub.2. The P.sub.1 first symbols and the P.sub.3 third symbols are sent.

A subchannel encoding device is configured to include: a probability distribution shaping-encoding unit for dividing M×N (M is an integer of two or more, and N is an integer of one or more) subchannels into N groups, shaping a probability distribution of transmission modulation symbols of each group on the basis of signal-to-noise ratios of the M×N subchannels, and converting an information bit string into a shaped bit string corresponding to the probability distribution of the transmission modulation symbols of each group; a subchannel signal generating unit for generating each subchannel signal in the M×N subchannels from the shaped bit string; and a signal multiplexing unit for multiplexing the M×N subchannel signals generated by the subchannel signal generating unit to generate a subchannel multiplexed signal.

A method of signal demodulation includes receiving, by a signal receiver, a first signal modulated by a symbol corresponding to a point in a constellation; generating, by the signal receiver and on the basis of the first signal, a modulation estimate; identifying, by the signal receiver and on the basis of the modulation estimate, a row or column of a candidate lookup table, the row or column corresponding to a region of the constellation; reading, by the signal receiver, from the row or column of the candidate lookup table one or more candidate points of the constellation, at least one among the one or more candidate points being more distant, from a center of the region, than a point, in the constellation, not among the one or more candidate points, and demodulating, by the signal receiver and on the basis of the one or more candidate points, the first signal.

A transmission method includes mapping processing, phase change processing, and transmission processing. In the mapping processing, a plurality of first modulation signals and a plurality of second modulation signals are generated using a first mapping scheme, and a plurality of third modulation signals and a plurality of fourth modulation signals are generated using a second mapping scheme. In the phase change processing, a phase change is performed on the plurality of second modulation signals and the plurality of fourth modulation signals using all N kinds of phases. In the transmission processing, the first modulation signals and the second modulation signals are respectively transmitted at a same frequency and a same time from different antennas, and the third modulation signals and the fourth modulation signals are respectively transmitted at a same frequency and a same time from the different antennas.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 64800 and a code rate of 7/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for quadrature phase shift keying (QPSK) modulation.

A receiving apparatus includes: a first decoder configured to decode a signal transmitted through a first layer from a layered division multiplexing (LDM) signal using a parity check matrix to generate low density parity check (LDPC) information word bits and parity bits; an encoder configured to encode the LDPC information word bits, generated by decoding the signal transmitted through the first layer, using the parity check matrix to generate parity bits corresponding only to preset columns in the parity check matrix; and a second decoder configured to decode a signal obtained by removing, from the LDM signal, a signal corresponding to the LDPC information word bits generated by decoding the signal transmitted through the first layer, the parity bits generated by the encoder, and the parity bits generated by the first decoder except the parity bits generated by the encoder, thereby to generate information word bits transmitted through a second layer.

It is presented a method for modulating data for transmission over a communication channel to a receiver network entity. The method is performed in a transmitter network entity and comprises the step of: modulating data in accordance with a modulation scheme, the modulation scheme comprising a first set of constellation points respectively representing only one bit sequence and a second set of constellation points respectively representing two different bit sequences.

To support a wide range of code rates in probabilistic shaping based modulation schemes solutions, a constellation which is at least based on a trained model is used in the modulation. Depending on an implementation the trained model may be a constellation comprising a plurality of sub-constellations with trained parameters as constellation points, or the trained model may be for generating a constellation and corresponding constellation points.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 64800 and a code rate of 7/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for quadrature phase shift keying (QPSK) modulation.

Consistent with the present disclosure, codewords indicative of a super Gaussian distribution may be encoded and decoded using the encoders and decoders disclosed herein. Based on such codewords, symbols may be transmitted in accordance or in conformance with a super Gaussian distribution to tailor the SE of an optical signal or subcarrier for a given link having non-linear degradations and shaping gain. Such tailed SE may not be achievable with a Gaussian symbol transmission probability distribution.