基于复数权值FIR滤波器的宽带波束形成方法

Constant Width Beamfoming Method Based on Complex FIR Filters

提出一种用于水声通信的宽带恒定束宽波束形成结构。该结构首先采用时间延迟线补偿各阵元接收信号间整数倍采样间隔时延。接着通过希尔伯特变换等方法将补偿后的实信号转换为复信号。最后将转换的复信号通过复数权FIR滤波器滤波对信号的幅度和分数间隔时延进行补偿。对提出的宽带波束形成结构进行了仿真验证。仿真中阵形为12元体积阵,通信频带为3k-7kHz。仿真结果表明:在设计的通信频带内,不同频率对应波束的旁瓣级为20dB左右,主瓣差别小于0.1dB。

A novel constant width beamforming structure used in underwater acoustic communication was proposed. In the proposed structure, complex FIR digital filters combined with tapped-delay-lines were used to weight the received signals. An algorithm which could calculate the coefficients of the complex FIR filters iteratively was proposed. Simulation of the proposed structure was done on an array of 12 sensors. The results show that inside the communication band, the differences between the mainbeams at different frequencies are less than 0.1dB.