一种新的稳健宽带SDL波束形成算法

A New Robust Wideband Beamforming Algorithm with Sensor Delay Lines

针对存在期望信号指向误差时宽带波束形成性能下降等问题,提出一种基于空间响应变化(SRV)和概率约束的稳健阵元延迟线(SDL)宽带波束形成算法。该算法首先建立SDL宽带阵列模型;然后假设期望信号导向矢量误差服从复高斯分布,并将基于一组不同频率上概率约束优化条件的稳健宽带波束形成问题转化为二阶锥规划的问题,可利用内点法有效求解;最后对阵列波束波动附加离散SRV约束,以提高频率不变性和简化概率约束优化条件。仿真实验表明,存在期望信号指向误差的情况下,该算法的计算复杂度低且具有良好的恒定束宽性能,较最差性能最优算法具有更好的稳健性和更高的输出信干噪比。

In practice, look direction error can severely degrade performance of the wideband beamformer. To improve robustness of the wideband beamformer against look direction error, a novel robust wideband beamforming algorithm with sensor delay lines （SDL） is proposed by employing the spatial response variation （SRV） and probabilistic constraints. Based on the SDL wideband model, this paper assume that the mismatch vector between the presumed and actual signal steering vectors is drawn from a com- sampling with a group of probabilistic constraints and can be solved with interior-point method after being reformed to the form of standard second order cone programming （SOCP）. Adding the SRV constraint to the fluctuation of the array spatial responses within the desired frequency band, the number of constraints is reduced and the frequency invariance property is improved. The simulations illustrate the effectiveness of the proposed algorithm.