Abstract: Two types of asymmetric turbo codes are proposed，which are consisted of the parallel concatenated turbo codes that use the different types of the component codes with different not only the constraint length but also the generator polynomial，the proposed scheme can improve the BER performance in the region of the lower SNR and reduce the error floor in the region of the higher SNR.The simulation results show the asymmetric turbo codes can perform better than the typical symmetric system at both low and high SNR with reduced decoding complexity.

摘要： 采用具有不同约束长度和不同类型生成多项式的递归系统卷积码作为Turbo码的两个分量码，设计了两类非对称Turbo码，可以有效地解决标准对称Turbo码在整个信噪比范围不能同时具有较好的误比特率性能和较低的错误平层的问题。计算机仿真结果表明采用非对称Turbo码，可以降低Turbo码的译码复杂性，实现Turbo码在低信噪比的性能和高信噪比的错误平层的良好折中，有效地改善Turbo码的整体误比特率性能。