抗频偏的突发GMSK混合信号单通道盲分离算法

Anti-frequency-offset algorithm on single-channel blind separation of burst GMSK mixed signals

针对突发GMSK混合信号的单通道盲分离问题,提出了一种基于逐幸存路径处理(PSP)的抗频偏盲分离算法。该算法通过在盲分离过程中对信道变化和频偏引起的相位变化分别进行跟踪,能大大提升算法对残余频偏的容忍能力。仿真表明,传统PSP算法能容忍的归一化频偏误差(相对符号速率)不大于2.0×10 4,而抗频偏算法在归一化频偏误差达1.5×10 2时仍然能收敛,且不需要对初始相位进行估计,同时分离性能相比理想条件下的PSP算法只下降了约1dB。

A per-survivor processing （PSP） based anti-frequency-offset algorithm was proposed for single-channel blind separation of burst GMSK mixed signals. The algorithm traces the phase changes caused by frequency offset and channel changes caused by other matters separately, which remarkably tones up the capacity against frequency offset. Simulation results show that the proposed algorithm can work well even when the unitary frequency offset （compared to symbol rate ） grows up to 1.Sx10-2, while the traditional PSP algorithm needs the unitary frequency offset less than 2.0x10-4. Further- more, the proposed algorithm has no need for phase initialization, and a loss of only ldB on performance can be achieved in comoarison with the traditional PSP algorithm.