Pilot-aided DOA estimation for CDMA communication systems

A pilot-aided direction-of-arrival estimation technique for code-division multiple access systems is proposed. The direction of arrival is estimated based on the computation of the phase shift between the reference signal and its phase-shifted version, which is obtained through subarray beamforming. Since the directions of arrival are estimated after interference rejection, the effect of cochannel interference on the estimation is significantly reduced. Further, since subspace estimation and eigendecomposition are not required, the proposed technique is computationally simpler than existing direction-of-arrival estimation techniques. Extensive simulations show that the proposed technique offers significantly improved estimation capacity, accuracy, and tracking capability relative to existing techniques.