The Research Of DOA Estimation In Array Signal Processing

Array signal processing is an extremely important branch of signal processing field. Especially in the past two decades, with the develement of the electronic technology, computer technology and the component technology, array signal processing has been increasingly widely applied to the field of radar, sonar, communication, seismic exploration, meteorology, radio astronomy, medical imaging and many other fields. Under this background, the technology of DOA estimation in array signal processing were deeply studied in this paper, consequently it provided reference algorithms to hardware implementation and software programming in direction finding and location system of array signal processing.The main works on this paper are as follows:Firstly, the current situation of study on the DOA estimation techniques based on array signal processing was present, and the current problems of this technology were pointed out. The parametric models about the signal DOA estimation were built, which based on reasonably simplify the signal transmission condition.Secondly, the effect that impact on the performance of subspace DOA Estimation algorithm was analyzed in detail,which based on the definition of signal correlation, the confusion caused by the coherent signals of previous narrowband DOA estimation was clarified and the simulations for its conclusions using Matlab were validated.Thirdly, combining with classic super resolution MUSIC algorithm, serious of factors which affect the performance of algorithms to DOA estimation have been qualitatively and quantificationally described. And on this basis, the decoherence-MUSIC algorithm was improved from two aspects to promote the real-time and the robustness of the algorithm, which are reducing the computational complexity and extending the array aperture.Finally, for the characteristics of widedband array signal, two kinds of wideband signal DOA estimation method have been effectively explored based on narrow-band signal DOA estimation methods, the one is non-coherent signal subspace method based on band decomposition,the other is coherent signal subspace method based on the focusing matrix.