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 co-channel 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.