滤波器后置的多目标数字波束合成方法

数字波束合成是多目标数字相控阵天线中一个核心处理模块。在采用FPGA 实现波束合成时,由于不同类型滤波器的存在,需要消耗大量DSP48 Slices 资源。根据目标信号具有频分复用的特点,同时考虑相控阵加权与信道化滤波、正交变换滤波的关系,可以将上述两种滤波器合并成一个滤波器,并且置于加权求和模块之后。新的波束合成方法在保持阵列增益不变情况下,使得后置滤波器个数仅仅决定于目标数量而不是阵元数量,从而大大减少FPGA 资源的消耗。论文不仅分析对比了传统方法和滤波器后置方法的DSP48 Slices 资源消耗,还通过方向图和阵列输出SINR 仿真来证明新方法的有效性。

Multi-target Digital Beamforming Methodology with Post Filter

Digital beamforming is the key part in the design of multi-target digital phased array antenna. However, beamforming will consume plenty of DSP48 Slices in FPGA realization due to the filters. Since the multi-target phased array uses frequency division multiplexing, the two type filters, i. e. channelized filter and orthogonal transform filter, could be combined into a single one if taking advantage of the relationship between these filters and weighted module. This action results in considerable reduction of resources consumption in FPGA directly. Furthermore, the benefit of resource consumption reduction does not imply the array gain for the desired signal. In the new strategy, the new filter has to be located after the weighted module and this is why it is called as post filter. The theoretical analysis illustrates that the number of filters is only decided by the number of the targets instead of array element. Computer simulations about array pattern and output SINR also prove the nice performance of the proposed methodology.