用权系数迭代的自适应波束形成器抑制干扰

Application of adaptive beamformer based on weight iterative algorithm to suppress interferences

针对RFI(radio frequency interference)在高频地波雷达中不同距离元的分布特点,在比较现阶段不同波束形成器的基础上,提出一种应用基于权系数迭代法的自适应波束形成器来抑制RFI干扰的方法。该波束形成器的初始权向量是用MVDR(minimum variance distortionless response)算法来获得,而其后迭代法中的权向量是基于LCMV(linearly constrained minimum variance beamforming)算法在上一次权系数的基础上得到的。其中两算法中的协方差矩阵都是由不含雷达回波信号的远距离元阵列快拍来构成,从而增加天线阵的自由度。最后通过对实际雷达数据的处理,验证了该方法的可行性。

Having compared the disadvantages and advantages of the conventional algorithms of adaptive beamformer,an adaptive beamformer based on weight iterative algorithm for suppressing radio frequency interference （RFI） is proposed according to the distributing properties of RFI in different range cell. The initial weight vector of the adaptive beamformer is obtained by using the algorithm of minimum variance distortionless response （MVDR）. The other weight vectors are computed by the algorithm of linearly constrained minimum variance （LCMV） based on the last time weight vector. The covariance matrix of the two algorithms, i. e. MVDV and LCMV, are constructed with the array snapshots in the far range cells which have not useful radar echo. So, the free degree of the antenna array is increased. The feasibility of the adaptive beamformer is proved by using it to process the actual radar data.