该文提出了一种容误码的线性分组码的参数盲估计算法。该方法首先基于线性分组码对偶码字的统计特性和Walsh-Hadamard变换解线性方程组的容错特性来实现对偶码字的判决,同时采用"3倍标准差"准则并根据理论分析给出了一个有效的判决门限。接着通过判断对偶空间归一化维数的最大值来实现码长和码组同步时刻的估计。最后利用对偶码字构造出相应的校验矩阵,实现了在较高误码率情况下对线性分组码参数的盲估计。计算机仿真结果表明,在比特误码率为0.03的情况下,该文所提算法仍能得到很好的估计效果。
A new approach is presented for blind estimation of linear block codes parameters with noisy data. Firstly, the proposed method exploits the statistical properties of the dual codes and Walsh-Hadamard transform to determine whether a code is belong to dual code or not. Meanwhile, from the principle of "3 standard deviation", a theoretical threshold to distinguish dual codes is induced. Then the code length and synchronization are estimated when the normalized dual space dimension reaches the maximum. Finally, the parity-check matrix is recovered by the dual codes. Computer simulation results show that the proposed method can provide good performance even when the bit error rate is 0.03.