一种基于分段CRC码级联Hash极化码的设计

极化码作为一种线性分组码,具有较低的编码复杂度和确定的构造,但当其为中短码长时,性能会有所降低。提出一种基于分段循环冗余校验(cyclic redundancy check,CRC)码级联Hash极化码的设计方法,该方法在原有Hash极化码(Hash-Polar)的基础上,采用CRC分段校验进行双校验,分段CRC码在译码过程中能辅助路径度量,即对译码路径进行修饰,以此提高路径选择的可靠性,提高性能;另外,分段校验是将校验码分散地添加到输入的信息序列中,译码时对于CRC不通过的情况,可提前终止译码路径以省去不必要的译码计算量。最后,译码结束时,Hash校验码对修饰后的L条路径进行校验,选出最佳译码路径。仿真结果表明,所提出的设计方法比CRC辅助的Hash极化码(Hash-CRC-Polar)误码性能更优异。在高斯信道下,当码长为128bit、码率为1/2、误码率为10时,所提出的基于分段CRC校验码的Hash极化码比Hash-CRC-Polar获得了约0.25 dB的增益。

Design of concatenated Hash-Polar code based on segmented CRC code

As a linear block code, the polarization code has a lower coding complexity and a definite structure, but when it has a short or medium code length, the performance will be reduced.A design method of concatenated HashPolar codes based on segmented cyclic redundancy check (CRC) codes was proposed, which was based on the original Hash-Polar code and used CRC segmented check for double check.The segmented CRC code could assist the path measurement in the decoding process, that was, modify the decoding path, so as to improve the reliability of path selection and the performance.In addition, the segmented check was to add the check code dispersedly to the input information sequence.If the CRC failed during decoding, the decoding path could be terminated in advance to save unnecessary decoding calculations.Finally, at the end of the decoding, Hash check code verified the modified L paths and selected the best decoding path.The simulation results show that the design method proposed has better bit-error-rate performance than CRC-assisted Hash-Polar (Hash-CRC-Polar).In the Gaussian channel, when the code length is 128 bit, the code rate is 1/2, and the bit error rate is 10^-3, the Hash-Polar code based on the segmented CRC code proposed achieves a gain of about 0.25 dB over Hash-CRC-Polar.