Abstract

The increasing demand for mobile communication services without a corresponding increase in RF spectrum allocation motivates the need for new techniques to improve spectrum utilization. CDMA systems and adaptive antenna array are two approaches that show real promise for increasing spectrum efficiency. In this research, we investigate the performance of different adaptive array algorithms, blind and non-blind, in the CDMA systems. Three algorithms, least-squares despread re-spread multitarget constant modulus algorithm (LS-DRMTCMA), Wiener solution with pilot channel on reverse link of 3G CDMA and least-mean-square (LMS) algorithm with training sequence, are developed. A C++ simulation testbed is created to compare the performance of these algorithms. It is shown from the simulation results that system performance is greatly improved by using adaptive array. Wiener solution with pilot channel can outperform the other algorithms in all the test situations considered (e.g., AWGN channel, four types of fading channels). However the LMS algorithm with training sequence has less computational requirements than the other algorithms.