| A major thrust area for array processing is direction of arrival (DOA) estimation. The research, as this thesis shows, has been on adaptive two-dimensional (2D) DOA estimation, i.e. extracting the azimuth and elevation of sources adaptively. The L-shaped array has been used for the purpose of 2D DOA estimation, as it is easier to analyze due to a lesser number of elements. The subspace-based Pisarenko harmonic retrieval method has been implemented adaptively using Thompson's model. In the course of this research, a novel joint processing technique has been developed for performing a single weight vector update across the 2D antenna array. Seven gradient-based algorithms have been used independently for performing the update on the antenna weights. Out of these, three are new modifications of the existing tangent gradient method, suggested by Douglas, Amari, and Kung. These modifications are computationally cheaper than the four general algorithms used, while achieving similar performance. |
