Abstract: A low-complexity soft-decision decoding algorithm based on the re-encoding technique was proposed for the BCH(15,11) code in BeiDou satellite navigation system. Several candidate information sequences were constructed by the soft-decision vector and then re-encoded in the algorithm if the error in the hard-decision result was detected. The correlation between each codeword and the soft-decision vector was calculated, and the codeword with the maximum correlation value was selected as decoding output. Simulation results show that the presented algorithm outperforms traditional hard-decision decoding at the expense of moderate complexity increase. Moreover, the storage of error-correction ROM signal is avoided. Hence, the presented algorithm is a good choice for decoding in a practical navigation receiver.

Key words: BeiDou, BCH code, soft-decision decoding, re-encoding