Performance of adaptive antenna array algorithms on the IS-95 reverse link

by Kong, William King

This thesis discusses the performance of a standard uplink IS-95 CDMA transmission system employing adaptive antenna techniques for suppressing interference in a single ce11 microceUular environment with 100% voice activity. Fading rates of 1 OHz and IOOHz, the resolvable and the unresolvable multipath cases. as well as non-RAKE and RAKE reception cases are investigated. Three types of algorithms are considered: recursive least squares (RLS) and two modified foms of the recursive adaptive beamforming (RAB). A single-antenna and a dual-antenna receiver are also considered for cornparison purposes. Simulation results show ihat a linear adaptive antenna array with eight array elements achieves at least double the capacity gain of the current IS-95 dud-antenna RAKE receiver with the use of feedback-previous-decision approach. The RLS algorithm outperforms both RAB algorithms slightly. but the RLS algorithm is phase-dependent and requires precise phase tracking. Both RAB dgonthms converge faster dian the RLS algori thm.