一种信道估计动态更新的逐幸存路径处理算法

水声信道复杂的时变特性会影响水声通信系统的性能,在设计时需要进行特殊考虑。利用逐幸存路径处理算法在无需插入训练序列的情况下即可同时进行信道估计和数据检测的特点,提出了一种信道估计动态更新的算法。该算法通过比较当前时刻各条幸存路径的分支量度来判断信道变化的情况,从而决定信道估计更新的时刻,达到动态更新信道估计的目的。仿真结果表明,所提出的基于信道估计动态更新的逐幸存路径处理算法能有效地跟踪信道变化的情况,在时变信道中使用能获得较好的性能。

A per-survivor processing algorithm based on data-depended updating of channel estimation

Measures should be taken to overcome the time-variability of underwater acoustic channel, which will degrade the performance of underwater communication systems. Per-survivor processing is an approximation of maxi- mum likelihood sequence estimation, and it provides a solution to carry out channel estimation and information detection at the same time without using training data. An algorithm is proposed in this paper that the channel estimations are updated depending on the received data. By comparing the current costs in different survivor paths, the variation of channel is measured, hence whether to update the channel estimation or not is decided. Simulation result shows that the per-survivor processing algorithm based on data-depended updating of channel estimation is a good solution to underwater communication system in time-varying channels.