高效联合LDPC编码递归MSK调制

High efficiently joint LDPC coded recursive MSK modulation

递归最小频移键控(minimum shift keying,MSK)中的差分编码器引起了调制后相邻符号间的相关性,对设计联合低密度奇偶校验(low-density parity-check,LDPC)编码递归MSK调制有较大影响。针对该问题,该文通过联合系统因子图的分析,将MSK编码部分与LDPC码采用增加最小环长及联合译码的处理,得到联合编码调制。仿真表明,在加性Gauss白噪声(AWGN)下误码率为10-5及采用LD-PC码(2560,1024)时,该联合方案比简单级联的递归MSK和LDPC码系统,性能提高约1.3 dB,实现了高效的联合编码调制。

The differemial encoding of the recursive minimum shift keying （MSK） induces correlations between the adjacent modulated symbols which affect the design of joint low-density parity-check （LDPC） coded recursive MSK modulation systems. A factor graph-based method was developed to design the optimal joint LDPC coded MSK modulation by increasing the length of the combined shortest loops in the ;ncoding part of the MSK and the LDPC code. Simulations show that the method gives efficiently joint LDPC coded recursive MSK modulation that is 1.3 dB better than simple concatenation for LDPC code （2560,1024） at a bit error rate （BER） of 10^-5 in an additive white Gaussian noise （AWGN） channel.