宽带波束域频率聚焦自适应波束形成算法

A Frequency-Focusing Adaptive Beamforming Algorithm in Wideband Beamspace

针对传统时延控制波束形成器无法适应宽带信号接收的问题,提出一种宽带波束域频率聚焦自适应波束形成算法。首先,通过时延控制方法在空间预设方位形成多个独立波束,利用傅里叶变换将多波束数据变换到频域,针对每个频点构造聚焦矩阵,通过聚焦变换将宽带信号对齐到同一参考频率;然后,估计子带聚焦后的协方差矩阵,并进行特征分解得到信号子空间;最后,利用基于特征子空间(ESB)的波束形成方法得到权矢量,实现自适应波束形成。仿真结果表明,该算法能够实现对宽带信号的自适应接收,具有良好的抗干扰能力和稳健性。

Aiming at the problem that conventional time-delay controled multi-beam system is not appropriate for wideband signal, a wideband beamspace frequency-focusing algorithm is proposed. Firstly, a series of individual beams, pointing to the designed directions, are formed via time-delay control system. The multi-beam data are trarisformed into frequency domain via FFT. The focusing matrix for each frequency point is formed. Then the＇wideband signal is aligned with the reference frequency point via focusing transform. Secondly, the covariance matrices of subbands are estimated and the signal subspaces are eigen-decomposed from those covariance matrixs. Finally, the weight vector is calculated via the ESB algorithm and the adaptive beam pattern can be achieved. The simulation results indicate that the proposed algorithm is able to receive wideband signals and the formed beam possesses excellent anti-jamming ability and robustness.