Joint 2-D DOA and TOA Estimation for Multipath OFDM Signals Based on Three Antennas

A method for estimating the 2-D direction- and time-of-arrival of orthogonal frequency division multiplexing (OFDM) signals that utilizes only three antennas is proposed. An array manifold matrix is first constructed not only based on the symmetry of circular geometry but also the time diversity of every OFDM subcarrier, so that the array aperture can be greatly increased. A virtual spatial smoothing method is then used to partition the array manifold matrix into structurally identical sub-array manifold matrix, so that coherent multipaths can be correctly estimated by incorporating the eigenstructure-based techniques on the average of the sub-array covariance matrices. Simulation results are provided to demonstrate the effectiveness of the proposed method.