Nonuniform Subband Method for Wideband Beamforming of Nested Array

A multirate nonuniform subband method with general parameter filter banks for wideband beamforming of harmonic nested array is proposed. The harmonic nested array is composed of several uniformly-spaced linear subarrays, each of which processes an octave subband signal. The nonuniform subband signal is generated by general parameter filter banks. Each subarray beamforming is carried out with space-frequency signal processing approach, and four subarrays share the same weights among themselves. Based on this kind of processing architecture, the proposed beamformer splits the wideband signal into several nonuniform narrow subband ones which are processed in parallel, and only one subarray weights are needed. In this way, the proposed beamformer greatly alleviate burden of demanding too many weights for the arrays and hence contributes to significantly decreasing the computational load and improving the speed as well. Simulations show that the proposed beamformer is competent for wideband beamforming with much lower computation complexity.