Direction-of-arrival estimation in the presence of finite distance broad-band sources

An extended method dealing with the problem of estimating one-dimensional (1-D) direction-of-arrival (DOA) of finite distance broadband sources is described. The method is extended from a computationally simple preprocessing scheme, referred to as the far-field approximation (FFA) method which has been proposed for the same problem involving narrow-band sources. The extension of the FFA method for wide-band source scenario applies the preprocessing algorithm to the narrow-band cross-spectral density matrices (CSDM) of array outputs at all frequency bins within the concerned frequency band and certain CSDM based wide-band DOA estimation method can then be used. Simulation results confirm the effectiveness of the proposed extension of the FFA method