Performance analysis of CDMA cellular systems with adaptive antenna arrays over multipath channels

This paper discusses the use of base station adaptive antenna arrays for code division multiple access (CDMA) cellular communication systems. We make use of only one beamformer in conjunction with a maximal ratio combining (MRC) RAKE receiver to deal with multipath scenario with multiple users. The performance analysis of the proposed system is developed with binary phase shift keying (BPSK) modulated signals over the Rayleigh fading multipath channel. We use the Gaussian approximation to model all interference. To simplify the evaluation of the interference from adjacent cells, the concentric circle cell geometry is employed in place of the common hexagonal cell geometry. The improvement in performance is quantified by comparison with the omnidirectional antenna system using realistic simulations. It is shown that the capacity of the linear array system is six times larger than the omnidirectional antenna system.