Adaptive DOA Estimation in Reflective Environments

Usage of spatial information in the DOA estimation of signals, overcome some weaknesses of time-processing techniques. In this paper, following the Direct Data Domain Least Square (D3LS) technique, amplitude information of signals arrived at each element in an antenna array are arranged in a square matrix in which, except for the first row, other entries are combinations of reflective signals, noise and interference. By forming an equation including this matrix, weighting factors of antenna array, and antenna gain, coefficients are calculated in such a way that all signals which their DOA is not important, i.e. reflected signals, noise and etc., reach their least quantity. Then, by making a symmetric square matrix and modification of the main equation according to Linear Conjugate Gradient procedure, weighting factors of antenna are obtained. Finally, it is shown by simulation that this procedure will accelerate the convergence process remarkably compared with D3LS technique