成像声纳中多波束形成的FPGA工程实现

FPGA Implementation of Multi-beamforming of Imaging Sonar

提出了一种计算方法简单、计算量小、所需存储量小的近场聚焦多波束形成的高速FPGA实现方法,用于成像声纳中高精度、高覆盖、高波束数的多波束形成。本方法基于180阵元均匀半圆阵,通过阵元等效弦的转动,仅采用6组加权系数矢量即可在90°范围内产生540个波束,使存储量降低了两个数量级,从而有效降低对硬件存储资源的要求。该系统工作在270 MHz,通过乒乓操作实现数据不间断的输入/输出,从而提高速度;通过多通道多系数复用乘法器和流水并行技术,仅采用24个乘法器完成了540个波束的实时产生,实现了8 190倍复用。

An FPGA implementation of high-speed digital near field focusing beamforming to generate high-precision, high coverage, high number beams which is simple with small amount of calculation and low requirement of storage is proposed in this paper. The method is based on a 180 elements uniform semi-circular array, through the rotation of the array elements＇ equivalent string, only 6 sets of weight vector are used to generated 540 beams that observe the entire field of view of 90 at one time. Thus, storage capacity was reduced by two orders of magnitude, which is greatly reduced the demand for storage. The system operates at 270 MHz. Through ping-pong op- eration, the speed is improved by continuous data writing and outputting; through multi-channel multiplexing and module reuse, 24 multipliers are used to form all the 540 beams, thus save the FPGA hardware resources 8 190 times.