误码条件下LDPC码校验矩阵的盲识别算法

A Blind Recognition Algorithm of LDPC Code Check Matrix in a Noisy Environment

针对误码条件下LDPC码校验矩阵难以逆向构造的问题,提出了一种LDPC码校验矩阵的盲识别算法。首先,构造含错矩阵,对其进行列消元,得到其对偶向量;然后,筛选出对偶向量中的有效LDPC码校验向量,剔除被截获数据中的含错码组;对上述步骤进行迭代,提高无误码码组的比例。将原误码条件下的棘手问题,退化为无误码条件下相对容易的线性约束关系的重建问题。仿真结果表明,在误码率不高于10^(-4)的非合作条件下,接收方可以重建发送方使用的LDPC码校验矩阵。

Aiming at the problem that the parity check matrix is hard to reverse construction in a low signal-to-noise environment, a blind recognition algorithm of parity check matrix is proposed in this paper. Firstly, the error matrix is constructed and its dual vector is obtained. Then, the code check vector in the dual vector is screened effectively to eliminate the error code group in the intercepted data, and the above steps are iterated to improve the ratio of the correct code group. The difficult problem under the original error condition is reduced to the relatively easy reconstruction of linear constraint relation under the condition of no error. Simulation results show that if the BER is not higher than the non-cooperative condition, the receiver can reconstruct the parity check matrix used by the sender.