基于水声信道的MAPSK-TCM编码调制技术研究

论述了应用于水声信道的网格编码调制TCM技术,分析了影响其性能的主要因素;针对水声信道带宽有限的情况,提出了在信号频带不展宽的情况下提高水声通信性能的多进制非对称MAPSK-TCM编码调制方法,并在给定的水声信道下,分别对码率为1/2、2/3的情况进行了仿真,仿真结果表明:MAPSK-TCM方法(M=4或8)相对于相同信号带宽的标准TCM方法,在信噪比相同的情况下,降低了系统的误码率,对改善水声通信的可靠性有重要意义。

Applying MAPSK-TCM Coding Method to Improving Long-Distance Acoustic Communication

Aim. It is well known that long-distance underwater acoustic communication presents a great many difficulties.Taking advantage of the achievements of past researchers,we combine them into a novel multiple asymmetric phase shift key and Trellis coded modulation(MAPSK-TCM) coding method.In the full paper,we explain in some detail the novel coding method combined by us and its application to simulating long-distance underwater acoustic communication.In this abstract,we just add some pertinent remarks to listing the two topics of explanation.The first topic is: the TCM coding method for underwater acoustic communication.In the first topic,we analyze the main factors which affect the performance of the coding method,including effective code length,minimum product distance and minimum Euclidian distance.Then,in the first topic,we explain how to combine past research achievements into MAPSK-TCM coding methods and why it can improve communication performance.The second topic is: the simulation results of the coding methods and their analysis.In the second topic,we present simulation results in Figs.5 and 6.The analysis of these results shows preliminarily that our novel asymmetric coding method is better than the non-asymmetric one for two different values of M:(1) when M=4,the 4APSK-TCM coding gain is 3.2 dB higher than that of 4PSK-TCM;(2) when M=8,the 8APSK-TCM coding gain is 2.3 dB higher than that of 8PSK-TCM.