基于最小错误判决准则的LDPC码码长及码字起点识别

Identification of LDPC Code Length and Code Word Starting Point Based on Minimum Error Judgment Criterion

现有LDPC码开集识别算法以码长及码字起点为已知条件进行识别,这导致算法的实际应用受限,为了克服这一缺点,提出了一种基于最小错误判决准则的码长及码字起点识别算法。首先,根据码长及码字起点估计值对接收序列进行截取构造码字分析矩阵;然后,对分析矩阵进行高斯列消元并获取疑似校验向量,进一步基于最小错误判决准则筛选出LDPC码校验向量;最后,寻找在不同码长及码字起点遍历值处校验向量个数的最大值,实现码长及码字起点的识别。仿真实验结果表明,在误码率为10^(-3)量级时,针对IEEE802.16E协议下的LDPC码,算法的识别率达到100%。

The existing LDPC code open set recognition algorithm uses the code length and the starting point of the code word as known conditions for recognitionwhich limits the practical application of the algorithm.In order to overcome this shortcomingthis paper proposes a code length and code word starting point recognition algorithm based on the minimum error judgment criterion.Firstthe received sequence is intercepted according to the estimated value of the code length and the code word starting point to construct a code word analysis matrixand then Gaussian column transformation is conducted on the analysis matrix and possible check vectors are obtained.The LDPC code check vector is further selected based on the minimum error judgment criterionand finally the maximum number of check vectors at different traversal values of code lengths and code word starting point is foundso as to realize code length and code word starting point identification.The simulation experiment results show that when the bit error rate is on the level of 10^(-3) the recognition rate of the algorithm reaches 100%for the LDPC code under the IEEE802.16E protocol.