Smart antenna with joint angle and delay estimation for the geolocation, smart uplink and downlink beamforming

In this paper, we propose an algorithm for joint estimation of the angle of arrival (AOA) and delay of each dominant multipath for the desired user for W-CDMA FDD uplink. After we estimate the so-called desired spatio frequency signal vector by using previously proposed processing scheme, we propose the 2D unitary ESPRIT algorithm as our estimator which provides closed-form, as well as automatically paired AOA-delay estimates. We effectively have a single snapshot of 2D data and thus require 2D smoothing for extracting multiple snapshots. Two 2D smoothing schemes, pre-eigenanalysis and post-eigenanalysis 2D smoothing, are discussed. Simulation results show that our algorithms can accurately estimate the AOA and delay for each multipath even under "near-far" conditions. The paired AOA-delay can be used in the smart uplink beamforming for the demodulation. Furthermore, the AOA information is useful for FDD downlink beamforming and source localization for emergency service. The simulation results for determining the location of the mobile station with the estimated parameters are also presented.