基于频控阵的改进ESB波束形成算法

频控阵由于其波束方向图具有的距离-角度二维依赖特性而受到广泛关注, 理想情况下基于频控阵的自适应波束形成技术, 能够从距离维和角度维增强期望信号并抑制干扰, 但实际系统中较大的指向误差和采样协方差矩阵失配会造成算法性能严重下降。针对该问题, 提出一种改进的基于特征空间(eigenspace-based, ESB)自适应波束形成算法, 并将其应用在频控阵多输入多输出接收处理体制中, 仿真结果表明在5°的指向误差内, -20 dB信噪比, 及小快拍数的非理想条件下, 所提算法仍然能在目标位置附近形成高增益, 并在干扰位置形成零陷, 克服了传统ESB算法低信噪比条件下算法失效导致的波束方向图畸变问题, 具有更好的适用性。

Improved ESB beamforming algorithm based on frequency diverse array

Frequency diverse array (FDA) has attracted much attention because of its two-dimensional dependence of beam pattern. Ideally, the adaptive beamforming technology based on FDA can enhance the desired signal from the dimension of distance and angle and suppress the interference. However, the large pointing error and the mismatch of sampling covariance matrix in the actual system will cause serious degradation of the algorithm performance. In order to solve this problem, an improved eigenspace-based (ESB) adaptive beamforming algorithm is proposed and applied to the frequency diverse array multiple-input multiple-output (FDA-MIMO) receiving and processing system.The simulation results show that under the non ideal conditions of 5° pointing error, signal to noise ratio of -20 dB and small snapshot number, the proposed algorithm can form high gain at target position, null at interference position, and overcome the beam pattern distortion problem caused by ESB algorithm failure under low signal to noise ratio, which brings better applicability.