An Iterative Joint Source-Channel Decoding Method Based on Arithmetic Codes and Low Density Parity-Check Codes

Abstract

The invention provides an iterative joint source channel decoding (JSCD) method based on arithmetic coding (AC) and low-density parity-check (LDPC). In the method, an encoding sequence b<h> is obtained by processing a source symbol sequence s<h> through an AC encoder, an input information sequence b of an LDPC encoder is obtained by processing D encoding sequences b<h>, a code word sequence x is generated by processing the b through the LDPC encoder, and is sent to an AWGN channel after being modulated by a BPSK, a receiving sequence r is input to a closed ring formed by an LDPC decoder and a Chase-SISO AC decoder to be subjected to iterative decoding, after a plurality of times of iterations, a decoding sequence shown in the description is output by the LDPC decoder, the sequence is converted by a serial-parallel converter to obtain a sequence shown in the description, and the former sequence is processed by the AC decoder to obtain a decoding symbol sequence shown in the description. According to the method, the AC very efficient in lossless compression and the LDPC coding very high in error resistance are combined, so that the system validity and the reliability are very high; and meanwhile, an IJSCD (Iterative Joint Source Channel Decoding) method is utilized, so that the reliability is further improved on the premise of ensuring the validity.

Description

technical field [0001] The invention relates to a joint source-channel decoding method in a wireless communication system, specifically an iterative joint source-channel decoding method based on arithmetic codes and low-density parity check codes. Background technique [0002] Source coding and channel coding are two indispensable parts of a communication system. The purpose of source coding is to remove source redundancy to improve the effectiveness of communication, and the purpose of channel coding is to add redundancy to improve communication reliability. In the traditional receiver structure design, the source decoding and channel decoding are usually considered separately, and the source information is not fully utilized. The Joint Source Channel Decoding (JSCD) method considers the source and the channel as a whole, so that the source information can be fully utilized, and the reliability can be further improved under the premise of ensuring validity. [0003] Arithm...

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Problems solved by technology

However, the disadvantage of this method is that it loses part of the compression efficiency of the arithmetic code, the calculation is large, and the implementation complexity is high.

[0006] In 2008, Feng Yuye proposed an adaptive IJSCD method based on arithmetic codes and systematic convolutional codes in his doctoral thesis "Research on Joint Source-Channel Coding and Decoding Based on Arithmetic Codes". Self-adaptively adjust the number of decoding nodes of the BCJR algorithm. Compared with the IJSCD method proposed by M.Grangetto et al., the amount of calculation is reduced, but when the length of the information bit is large, the amount of calculation of this method is still very large. Huge, difficult to achieve

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