一种新的应用于水声信道的空间分集均衡器

摘要

Underwater acoustic communication is difficuIt because the fading muItipath channeIs have high-order QAM sig-naIs. A new SpatiaI Diversity EquaIizer( SDE)is proposed to overcome the inter-symboI interference( ISI)in underwater a-coustic channeI. The aIgorithm in the proposed SDE consists of constant moduIus aIgorithm( CMA)part and muIti-moduIus bIind equaIization aIgorithm part. The second part of the proposed SDE can use the different moduIus nature of the high-order QAM signaIs to improve the equaIization performance. Compared with the traditionaI SDE based on CMA,the proposed SDE can obtain the Iower steady-state mean square error and faster convergence rate. The performance of the proposed SDE is shown in underwater acoustic channeIs by computer simuIations.%水声信道存在天然的多径衰落特性使得水下声通信变得极其困难，尤其在高阶QAM情况下更为严重。因此针对水声信道提出了一种新的空间分集均衡器来克服由多径衰落引起的码间干扰。该空间分集均衡器中使用的算法由常数模算法和多模算法两部分组成。其中的多模算法部分能够利用高阶QAM信号位于不同的模值上的特点来提高新空间分集均衡器的性能。和基于常数模算法的传统空间分集均衡器相比，新的空间分集均衡器具有低稳态均方误差和快收敛速度。水声信道中的计算机仿真实验验证了新方法的有效性。