Comparative study of pilot symbol assisted (PSA) beamforming techniques for (3G) WCDMA reverse link

The uplink signal format of a Wideband Code Division Multiple Access (WCDMA) system which has been widely accepted as the air interface for the coming Third Generation (3G) cellular standard has been considered. The capacity of cellular system is limited by multipath fading and Multiple Access Interference (MAI). A beamformer-Rake receiver is a computationally feasible solution to allow temporal-spatial signal processing for effectively overcoming signal fading and MAI. In this paper, the performance of PSA beamformer-Rake receivers in the Geometrically Based Single Bounce (GBSB) circular channel with the uplink W-CDMA signal standard has been investigated. The Least Mean Square (LMS) and the Direct Matrix Inversion (DMI) as PSA-based beamforming techniques have been considered. Maximal Ratio Combining (MRC) coherent RAKE receiver with different number of fingers is considered for simulation. The performances of the aforementioned two PSA-based techniques are compared in terms of BER against number of users in the following scenarios: antenna elements, RAKE fingers, and beamforming algorithms.