Mapper based on bit weaving code modulation system and mapping process thereof

Abstract

The invention discloses a mapper and a mapping method based on a bit interleaving coding modulation system, and mainly solves problems of the prior coding modulation system including low spectrum efficiency and high bit error rate. The mapper adopts a structure in which interblock is based on approximate Gaussian distribution and intrablock is based on the rule of minimum hamming distance. The mapping method for mapping 32 information symbols to a 16-QAM constellation comprises the following mapping steps: 1) ensuring that every five bits in an input bit sequence are corresponding to an information symbol; 2) realizing grouping of different information symbols and respectively mapping each group to a constellation map and constellation points at different Euclidean distances from an origin; 3) setting the front two bits of an information symbol identical in each quadrant of the constellation map, and ensuring that the different number of the last three bits of different symbols corresponding to each constellation point is one or two; and 4) mapping all information bit sequences to a selected constellation map and converting the information bit sequences into symbol sequences. The mapper and the mapping method have the advantages of high spectrum efficiency and low bit error rate, and can be used for data transmission of a demodulation and decoding joint iterative system.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to an improvement of a signal mapper and a mapping method thereof, which can be used for data transmission of a joint iterative demodulation / decoding system. Background technique [0002] Traditional coding and modulation systems are mainly composed of encoders, mappers, demappers and decoders, such as figure 1 shown. The traditional coded modulation system maps the signal symbols to the constellation points equally, for figure 1 In the 4-PAM constellation on the left, each constellation point represents an information symbol. The mapper corresponds the input bit sequence to an information symbol with 2 bits: when the input sequence is 00, it corresponds to the constellation point "-3"; when the input sequence is 01, it corresponds to the constellation point "-1"; when the input sequence is 10, It corresponds to the constellation point "+1"; when the input seque...

AI Technical Summary

Problems solved by technology

[0015] The disadvantage of the BICM system is that the spectrum utilization rate is not high. Although the spectrum efficiency has been improved after the introduction of the traditional Gallager mapping, it has brought about the deterioration of the BER performance of the system.

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