一种基于自适应阵列天线的波束赋形算法

自适应阵列天线中的数字波束赋形(DBF)技术是智能天线数字信号处理部分的核心.提出了一种可用于自适应阵列波束赋形的SMI-LMS算法--由SMI(采样协方差矩阵求逆)算法决定LMS(最小均方)算法的初始权向量.该算法充分结合了SMI算法收敛速度快和LMS算法稳态误差小的优点,能在较强干扰环境下,确保权向量的快速收敛和跟踪速度.与传统的LMS算法相比,SMI-LMS算法具有良好的收敛性能、较快的跟踪速度和较小的输出误差,并可以有效改善自适应方向图的副瓣性能.仿真结果验证了该结论.

A Beamforming Algorithm for Adaptive Arrays

The adaptive digital beamforming(DBF)algorithm is the core of adaptive array in the smart antenna technique.In this paper,a combination of two major adaptive algorithms,the SMI(sample matrix inversion)algorithm and the LMS(least mean square)algorithm,is presented,in which the SMI method is used to determine the initial weights for the LMS operation.The new algorithm,fully taking advantage of the merits of the LMS algorithm with simplicity and small static error and the SMI algorithm with rapid convergence,can ensure the weigh vectors fast convergence and tracking in stronger interference environments.Compared with traditional LMS method,the SMI-LMS method not only has the attributes of both faster convergence and smaller output error,but also can effectively improve the side-lobe performance.Numerical simulations verify the conclusion.