Spatial wavelet transform preprocessing for direction of arrival estimation

The spatial discrete wavelet transform preprocessing (SDWTP) scheme is proposed to improve the performance of high resolution DOA estimation algorithms in light of the duality between spatial domain and temporal domain. The novel preprocessing technique gives rise to better resolving ability and lower SNR resolution threshold and more importantly, a following reduced-dimension processing inherent in the discrete wavelet transform can reduce the computation cost considerably. Besides, a parallel implementation of DOA estimation in each spatial frequency subband individually can also be introduced to save the computational time. Computer simulation results are presented to illustrate the effectiveness of new preprocessing technique.