Improved BCH soft-decision decoding algorithm

Abstract

The invention discloses an improved BCH soft-decision decoding algorithm with the object of resolving the problem in the prior art that a current BCH soft-decision decoding algorithm is complex to perform and decoders are often too much delayed. The improved algorithm is performed through the following steps: firstly, choosing t positions of code symbols with least credibility, according to inputted soft information, as estimated error positions and seeking the numbers of error positions in their corresponding finite fields; conducting hard decision to the inputted soft information for binary BCH codes and seeking an initial adjoint polynomial; fourthly, seeking a polynomial for error positions based on the updated adjoint polynomial; if the supreme power from the polynomial for error positions is less than the maximally correctable number t of a BCH decoder, then seek the error image patterns; otherwise, go back to the third step; and completing decoding by correcting the codes obtained by hard decision to the error image patterns. According to the invention, the soft decision decoding algorithm is made less complex and delay of decoders is shortened, and the algorithm can be applied in error control coding.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to an improved BCH soft-decision decoding method, which can be used for decoding BCH codes defined in communication standards such as DVB-S2, DVB-S2X, and WBAN. Background technique [0002] In the communication process, because the digital signal is subjected to various interference factors in the channel transmission, the signal quality is degraded, the code is lost or the code is wrong, so it is necessary to perform some special processing on the digital signal before the signal transmission, and add certain control in a certain way. Error codes are used to achieve the purpose of automatic detection and error correction. This process is called channel coding. Error correction control coding technology is a kind of channel coding, which is widely used in various communication systems. BCH (Bose-Chaudhuri-Hocquenghem) code is an important error-correcting code. I...

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Problems solved by technology

[0003] The coding gain of the BCH code is related to the decoding algorithm. The soft-decision decoding algorithm can achieve better coding gain, but in order to obtain better decoding performance, the implementation of soft-decision decoding is much more difficult than hard-decision decoding: 1. Higher hardware complexity: In addition to a hard-decision decoder core, the soft-decision decoder needs to add an additional module to calculate and compare the difference between each candidate codeword and the received sequence before the hard decision. Euclidean distance, the multiplication and addition and comparison operations involved in this will occupy a larger hardware area and cause a lot of power consumption

2. Greater decoding delay: each candidate codeword generated by the soft-decision decoding algorithm must undergo a complete hard-decision decoding. The most commonly used soft-decision decoding algorithm is the Chase-II algorithm. The test sequence is 2 t , where t is the maximum number of errors that can be corrected by the BCH code, so the decoding delay of the Chase-II algorithm should be 2 times that of the hard decision decoding t times, grows exponentially with t, when the code length is very long, such a large decoding delay is unacceptable

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