基于DFT插值的线性约束最小方差宽带自适应阵列

Linearly constrained minimum variance broadband adaptive array based on DFT interpolation

本文提出一种具有频率不变波束图的线性约束最小方差宽带自适应算法。首先给出了具有频率不变波束图的连续线阵的灵敏度函数与离散线列阵加权系数之间的关系,然后给出了使用DFT插值法求解各子带阵列权系数的方法,最后将DFT插值法应用于线性约束最小方差宽带自适应阵列。理论分析及仿真结果表明,该算法可以在实现最小方差波束形成的同时保持波束图基本不随频率变化,且该方法可以降低宽带自适应阵列的运算量。

Based on the DFT interpolation method, an algorithm for linearly constrained minimum variance broadband adaptive array, whose beampattern is frequency invariant, is presented. Firstly, relationship between weights of a discrete sensor array and the sensitivity distribution of a continuous linear array, which has a property of frequency invariant beam pattern, is presented. Then, by employing the relationship between weights at a reference frequency and weights at an other frequency, weights at the other frequency are given by using the DFT interpolation method. Lastly, the DFT interpolation method is applied to linearly constrained minimum variance broadband adaptive array. The theoretical and simulation results show that the proposed algorithm can solve the minimum variance beamforming problem and at the same time ensure the beampattern frequency invariance.