基于FPGA的LMS滤波器在水声信道均衡中的应用仿真

Application Simulation of LMS Filter Based on FPGA in Underwater Acoustic Channel Equalization

本文介绍了射线声学理论,从理论方面分析水声信道模型,并用Matlab脚本编程实现BELLHOP模型,完成了水下声信道的建模,模拟真实海洋环境对声波信号产生的噪声以及多径干扰,以获取复杂环境背景下的水声信号。且利用FPGA编写RTL代码,用硬件的方式实现了LMS自适应滤波器。最后在Modelsim仿真平台上验证设计的滤波器对水声信道均衡的效果,结果显示LMS自适应滤波器能较好地消除信号中噪声以及多径干扰造成的影响,为水声通信工程实现中的信道均衡问题提供了一种简便的解决方法。

This paper introduces the theory of ray acoustics, analyzes the underwater acoustic channel model from the theoretical perspective, realizes the BELLHOP model with Matlab script programming, completes the underwater acoustic channel modeling, simulates the noise and multipath interference generated by the real ocean environment to acoustic signals, in order to obtain underwater acoustic signals under the complex environmental background. The RTL code is written by FPGA, and the LMS adaptive filter is implemented by hardware. Finally, the effect of the designed filter on underwater acoustic channel equalization is verified on the Modelsim simulation platform. The results show that the LMS adaptive filter can better eliminate the influence caused by noise and multipath interference in the signal, which provides a simple solution to the channel equalization problem in underwater acoustic communication engineering.