一种新的频域自适应波束形成算法

A Novel Frequency Domain Adaptive Beamforming Algorithm

在分析传统自适应波束形成的基础上,提出了一种新的频域自适应波束形成算法。该波束形成算法先对输入信号进行FFT,然后在空间频域上带通滤波,最后通过LMS(最小均方)算法实现自适应波束形成。FFT变换后信号自相关下降,LMS算法收敛速度提高;空间频域上带通滤波可以消除带外的干扰信号,实现容易;带通滤波后的信号维数大大下降,LMS算法计算量和存储量大大降低,收敛速度进一步提高。理论分析和仿真结果表明了该算法收敛速度很快、性能较好,且计算量和存储量较少,易于实时实现。

A novel frequency domain adaptive beamforming algorithm was presented. The received signal from array antennas was analyzed, and it shows that different DOAs correspond to different spatial frequency, and the received signal is the result of addition of different spatial frequency signals. That is the foundation of adaptive beamformer in frequency domain. This novel adaptive beamforming algorithm uses FFT for the received signal, passes the band-pass filter and finally uses the LMS algorithm to implement adaptive beamforming in the frequency domain. FFT-ed signal has a better decorrelation and leads to better convergence of LMS algorithm. Band-pass filter can suppress the interference signals outside of the band. Band-pass filtered signal can reduce its dimension greatly, which leads to reduce the amount of calculation and storage of LMS algorithm, and the convergence will speed up further. Theoretical analysis and simulations demonstrate that this algorithm converges faster than the conventional adaptive beamforming algorithm, and that it has better performance, requiring less amount of calculation. Finally, the algorithm is no more complex and can be implemented easily, and can be widely used. Besides, the beamforming algorithm is robust to coherent resource.