基于LDPC码结构的盲信道噪声方差估计方法

A blind channel estimation method based on the code structure of LDPC codes

在LDPC码的迭代软判决译码算法中需要利用信道的噪声方差,通过对二元LDPC码、采用BPSK调制的盲信道噪声方差估计方法的分析,提出了在AWGN信道条件下,采用QPSK调制的基于多元LDPC码结构的盲信道噪声方差估计算法,将估计的结果应用到多元LDPC码的译码算法中。仿真结果显示,该算法可以有效地提高信道利用率,在没有增加额外开销的同时能够得到比较准确的信噪比估计。

The noise variance of the channel is necessary in the iterative soft decoding algorithm of LDPC. In this paper, by analyzing the blind channel estimation algorithm based on binary LDPC codes with BPSK modulation, we propose a channel noise variance estimation algorithm that utilizes the characteristics of the QPSK modulation and the structure of nonbinary LDPC in the AWGN channel. The novel estimation method is a fast channel estimation algorithm. We use the estimation result into decoding algorithm of nonbinary LDPC codes. The simulations show that this algorithm can get a better SNR without extra bandwidth and transmission power. This channel estimation can improve the LDPC decoding performance and the channel efficiency.