A direction-finding algorithm based on a reversed antenna array

A direction-finding algorithm for a uniform linear array using a reversed beamformer and pilot signal training is presented in this paper. The direction-of-arrival (DOA) estimate for a signal of interest is derived using the phase difference between the output of a conventional beamformer and that obtained by reversing the antenna signals and conjugating the weights of a second beamformer. The proposed DOA estimation algorithm has a low computational complexity and improved performance in high cochannel interference environments compared to a recent subarray approach. Properties of the estimator are evaluated via a least-squares analysis, and the results are verified with a computer simulation example using wideband code-division multiple-access signals.