Research Of Doa Estimation Algorithm Of Wideband Array Signals

Spatial spectrum estimation is one of the main research directions of the array signal processing, it focuses on the estimation ability of multifold signal parameters. The main purpose of spatial spectrum estimation is estimating the airspace parameters or location of the signal, it has a broad application prospect in many fields such as radar, communication and sonar.Last three dacades, direction-of-arrival (DOA) estimation algorithm about narrow-band signals has been comparatively mature. The multi-source wideband signal DOA estimation is receiving more and more attention. Compared with narrowband, Wideband signal has the merit of more information, which is good for targets detecting and parameters estimation, thus research on wideband signal DOA estimation algorithms makes important practical significance. But wideband signal processing is in need of further enhancing its estimation performance with the greatly increased research in this area. Based on uniform linear array, this thesis makes a research on wideband signal DOA estimation algorithms, noise suppression and fast processing. The main works are summarized as follows:1. The classical narrow-band high-resolution DOA estimation algorithms have been discussed, and analyzed the performance of MUSIC algorithm through computer simulations.2. CRB for broadband high-resolution DOA estimation have been discussed. Combination of Cramer - Rao Bound (CRB), DOA estimation of broadband coherent signals'CSM algorithms have been analyzed and compared through computer simulations. The key problem is the structure of focusing matrix, which generally requires an estimation of initial angle and the selected frequency to determine the focusing matrix. Primary values make a great impact on the effect of CSM algorithm.3. Based on the CSM algorithm, a improved algorithm is given to estimate broadband coherent signal. It applies the principle of differential spatial smoothing algorithm to wideband signal DOA estimation, in order to reduce the impact of the array errors. The simulation results show that this algorithm can improve the ability to solve coherent signal and it has high stability.4. The wideband direct processing algorithms have been discussed. The performance of wideband direct processing algorithms have been analyzed compared with CSM algorithms through computer simulations.