一种时域波束形成系统的工程实现方法

An Engineering Implementation Method of Time-Domain Beam Forming System

相对于频域波束形成造成的帧间相位不连续,时域波束形成可对阵列输入信号进行精确时延从而得到相位连续的波束。设计了一种时域波束形成系统的工程实现方法。该方法将通道校正和波束形成分开,采用可变分数真延迟滤波器设计方法在线生成通道校正系数和波束权值;采用基于多项滤波和分布式算法实现的FIR滤波器结构,解决了高采样率信号对实时滤波器的要求。与基于乘法器实现的时域波束形成系统相比,该系统不使用乘法器,对FPGA逻辑的消耗也有明显降低,系统可根据资源灵活配置波束数目。

Relative to interframe phase discontinuities caused by frequency-domain beam form- ing, the input signal of the array could be delayed by the time-domain beam forming accurately, so that the phase continuous beam can be obtained. An engineering implementation method of time-domain beam forming system is designed, and the channel correction could be separated from beam forming. The method of variable fractional delay filter design is used to generate channel correction coefficients and beam weights online. The FIR filter structure based on poly- phase decomposition filtering and distributed algorithm is adopted to solve the requirement of high sampling rate signal to real time filter. Comparison with time-domain beam forming system based on multiplier, this system does not use multipliers, and the consumption of FPGA logic resources is also significantly reduced, the system can flexibly configure the number of beams according to resources.