连续相位调制的非相干减少状态差分序列检测算法

Noncoherent Reduced State Differential Sequence Detection of Continuous Phase Modulation

该文提出了连续相位调制的一种非相干减少状态的差分序列检测(RSDSD)算法。该算法基于减少状态序列检测(RSSD)的思想,利用简化状态格状图进行一码元差分Viterbi检测。分析了全响应连续相位调制(CPM)信号和部分响应CPM信号简化状态格状图的最小平方欧氏距离。在AWGN信道下以八进制h=1/8的2RC信号为例给出RSSD和RSDSD算法的性能。对不同的简化方案以及存在多普勒频移时相干RSSD和非卡甘干RSDSD的性能进行了比较。仿真结果表明:所提出的算法比相干最大似然序列检测在10-3误比特率时信噪比损失约为2dB,但它对于载波恢复困难的情形更为合适和稳健。

A noncoherent Reduced State Differential Sequence Detection （RSDSD） for Continuous Phase Modulation （CPM） is proposed in this paper, The algorithm makes use of the reduced state trellis based on Reduced State Sequence Detection （RSSD） and performs one-symbol differential Viterbi detection. The minimum square Euclidean distance of the reduced state trellis is analyzed for full response CPM and partial response CPM. Performance of RSSD and RSDSD is simulated for octal 2RC signal with h=1/8 in the AWGN channel and comparisons are made between different reduction schemes and between coherent RSSD and noncoherent RSDSD with Doppler frequency shifts. Simulation results show： although the proposed algorithm is degraded by 2dB at 10^-3 bit error rate compared with coherent Maximum Likelihood Sequence Detection（MLSD）, it is more appropriate and robust to the situation when the carrier recovery is difficult.