Joint angle and delay estimation for reduced dimension space-time RAKE receiver with application to IS-95 CDMA uplink

We propose an algorithm for joint estimation of the angle of arrival (AOA) and delay of each dominant multipath for the desired user for use in a reduced dimension space-time RAKE receiver for DS-CDMA communications that is “near-far” resistant. After we estimate the desired spatio-frequency signal vector, 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. The comparative performance of two 2D smoothing schemes, pre-eigenanalysis and post-eigenanalysis to smoothing, is discussed. The space-time data model for the IS-95 uplink is presented. The performance of a reduced dimension space-time RAKE receiver for the IS-95 uplink using the AOA-delay estimates is assessed through Monte-Carlo simulations