基于迭代变加权最小二乘的宽带波束赋形方法

A Method for Broadband Shaped Beam Based on Iterative Variably-Weighted Least Squares

针对常规加权最小二乘宽带波束形成中存在较大主瓣增益损失和旁瓣电平偏高的问题,提出了一种基于迭代变加权最小二乘的宽带波束赋形方法。首先通过合理设计加权函数和参考波束同步迭代优化波束主瓣区域和旁瓣区域对应的加权函数值;然后对波束最小旁瓣电平进行调整并更新加权值,以获得低旁瓣宽带近似频率不变波束形成器。与常规加权最小二乘法相比,有效减小了波束主瓣增益损失,改善了波束的频率不变特性,并降低了宽带波束最高旁瓣电平。仿真结果表明该方法的有效性。

To solve the problem of a great mainlobe gain loss and high sidelobe level in the conventional weighted least squares（WLS） broadband beamforming methods, a novel variably WLS broadband beamforming method based on iterative variably weighted values is proposed. First, the weighted function and reference beam pattern are properly designed to iterativly optimize the weighted values simultaneously in mainlobe and sidelobe areas, and then the minimum sidelobe level is adjusted and the weighted values of beamformer are updated for obtaining the design of approximately invariant frequency broadband beam shaper with sidelobe attenuation. Compared with the conventional WLS broadband beamshaper, a more efficient and effective control over the beamshaper mainlobe gain loss and sidelobe level is achieved, thus improving the frequency invariant property and decreasing the higher sidelobe level. Simulation results demonstrate the validation of the proposed method.