On spatio-frequential smoothing for joint angles and times of arrival estimation of multipaths

Abstract

A natural extension of the "Spatial" smoothing preprocessing technique is presented and analysed. It is well known that subspace methods do not work properly in the presence of coherent sources. In this paper, a "Spatio-Frequential" smoothing technique is described when the transmit OFDM symbol is received through multiple coherent signals using a uniform linear antenna array. After this preprocessing technique, one could efficiently apply any 2-dimensional subspace method to jointly estimate the angles and times of arrival of the incoming coherent signals. Simulation results demonstrate the potential of the proposed 2D smoothing method over existing separate spatial or frequential smoothing techniques.