基于软判决下的不删余极化码参数识别

Recognition of non-drilled polar codes based on soft decision

针对极化码盲识别问题,首先证明了能表征实际极化码码长、码率关系的定理1和定理2及区别冻结比特位和信息比特位的定理3。基于这3个定理,通过遍历可能的码长值,构建了码字矩阵和克罗内克矩阵,然后遍历信息比特位,检测码字空间与疑似对偶空间的校验关系。为了检测校验关系,引入了对数似然比概念,基于其统计特性和最优准则,估计出该遍历码长下的码率及信息比特位置,最终完成参数的识别。仿真结果表明,3个定理的结论与仿真结果一致,且算法具有较强的容错性,在信噪比为6.5 dB、码长为1024条件下,参数识别率能够达到98%以上。

In order to solve the problem of the blind recognition of polar codes,the theorem 1 and theorem 2 were proved firstly,which reflects the relationship between length and rate of actual polar codes,and then theorem 3 which could distinguish frozen bit and information bit positions was also proved.Based on these three theorems,the codewords matrixes and Kronecker matrixes were constructed by traversing the possible code length values.Then the information bits were traversed to detect the check relationship between the codewords and the suspected dual space.In order to detect the check relationship,log likelihood ratio was introduced,based on its characteristics and optimal criteria,the code rate and information bit positions were estimated.The simulation results show that the conclusions of the three theorems are consistent with the results.At the same time,the proposed algorithm has a strong error tolerance.Under 6.5 dB and code length of 1024,the rate of recognition can reach more than 98%.