分组码级联极化码

为提升极化码译码性能，提出一种级联极化码方案．采用经典分组码作为外码，极化码作为内码．选择所在子信道置信度较低的信息比特进行外码编码，将编码产生的校验比特放置在置信度最高的几个子信道位置上，再将这些校验比特与要传输的信息比特一起进行极化码编码．利用外码产生的校验比特有效地提升了极化码的译码性能．同时给出修正的连续删除列表译码算法，在原始的连续删除列表译码器译码结束后，将译码器列表中每一条译码结果所包含的校验比特分别进行校验，选择正确率最高且可通过校验的一条译码结果作为最终输出．仿真结果显示，在码长为128、误帧率为10^-2时，与循环冗余校验辅助的极化码方案相比，级联极化码方案有0.25dB的增益．

Block codes concatenated polar codes

To improve decoding performance, a concatenated polar codes coding scheme is designed which uses classical block codes as outer codes and polar codes as inner codes. The information bits with low confidence of the sub-channel are first encoded by the outer code. Then, all information bits and the parity check bits generated by the outer code are put into the polar encoder. It is shown that allocating the most trusted sub-channels to the parity check bits generated by the outer code can improve the performance of the proposed scheme, i.e., a lower decoding error probability can be achieved. A modified successive cancellation list decoder is also proposed. This decoding algorithm chooses the one with the highest correct probability of all the checked decoding results as the final output. Simulation results show that when the code length is 128 and the error frame rate is 10^-2, the proposed scheme has a gain of 0.25dB over the polarization code scheme with cyclic redundancy check.