Study On DOA Estimation Algorithm Of Wideband Array Signals

Estimation of signal parameters is an important research area of signal processing with growing applications in engineering and intensive research in theory. In recent years, much interest focuses on research and development of parameter estimation based on different application background, such as radar, sonar, communication, biomedicine, etc. This dissertation concentrates on the study of Direction-of-Arrival (DOA) for wideband signals.The Incoherent Signal-subspace Method(ISM) is analyzed, and Modified Music algorithm is used to improve the resolution of ISM and make it work in the presence of coherent wideband signals. Then the Coherent Signal-subspace Method(CSM) is discussed. The performance of DOA estimation affecting by the focusing matrix and focusing frequency has been studied. Rules of selecting the optimal focusing matrix and focusing frequency are investigated.A novel method for improving wideband signals DOA estimation in the presence of colored noise with unknown spectral matrix is presented. It is a combine of the propagator method and Two-side Correlation Transformation(TCT) method. Based on the propagator method, noise correlation matrix is constructed by array signals and a fast TCT focusing matrix is developed. The proposed method requires only linear operation but does not involve eigendecomposition, so that it has lower computation load. Extensive simulations demonstrate the performance of the proposed methods.