Blind identification of encoders has received increasing attention in recent years. In this letter, we focus on LDPC coded communication systems and study the problem of blind identification over a candidate set. We propose a blind identification method based on a two-stage maximum a posteriori probability estimation. The first stage measures the parity-check relationship between the received vectors and the rows of the parity-check matrices in the candidate set, and the second stage deals with the effect of row weights. Moreover, We theoretically explained the mechanism by which row weight affects identification results and proved that the proposed method can considerably suppress the preference of the existing methods for low row weights. Simulation results show that the proposed method always has a higher probability of correct identification for parity-check matrices with high row weights in the candidate set than the existing methods.

中文翻译：

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LDPC码盲识别的两阶段最大后验概率方法

近年来，编码器的盲识别越来越受到关注。在这封信中，我们专注于 LDPC 编码的通信系统并研究候选集上的盲识别问题。我们提出了一种基于两阶段最大后验概率估计的盲识别方法。第一阶段测量接收向量与候选集中奇偶校验矩阵的行之间的奇偶校验关系，第二阶段处理行权重的影响。此外，我们从理论上解释了行权重影响识别结果的机制，并证明所提出的方法可以显着抑制现有方法对低行权重的偏好。