为了适应光通信发展的要求, 依据分组Turbo码(BTC)传统Chase译码算法的分析, 提出了一种基于不对等可靠位数的改进新译码算法。使用该算法在每次迭代时将产生一个可靠度参数对外部信息进行修正, 从而提高BTC的译码性能。仿真结果表明: 在误码率(BER)为10-5且迭代4次的情况下, 新BTC译码算法与传统Chase译码算法相比, 其净编码增益(NCG)提高了0.9dB, 并且在最差情况下给系统增加的译码复杂度都不大。

In order to meet the development demands of optical communications, a new improved decoding algorithm, based on nonidentity of the reliable bits, is proposed according to the analysis of the traditional Chase decoding algorithm of the block turbo code (BTC). A reliable parameter to correct the outer information will be produced by applying the new algorithm at every iteration time, thus the decoding performance of the BTC is enhanced. The simulation result shows that the net coding gain (NCG) of the new BTC decoding algorithm is 0.9dB higher than that of the traditional chase decoding algorithm at the bit error rate (BER) of 10-5 and iteration times of 4. Furthermore, under the worst condition, the new decoding algorithm does not largely increase the decoding complexity.