Application of APES to adaptive arrays on the CDMA reverse channel

This work compares the performance of various beamforming algorithms for the mitigation of multiple access interference in adaptive array code-division multiple-access (CDMA) systems. The Fourier and linear constrained minimum variance (LCMV) methods are both well-known algorithms for beamforming. While the LCMV method has many advantages, it can result in high noise gain under certain conditions. The recently developed amplitude and phase-estimation (APES) method has been shown to have better noise-gain performance. The APES filter is derived for the spatial case and simulation results are compared to those of both Fourier and LCMV under various scenarios of the CDMA reverse channel. Further, the effects of the use of multiple constraints on the beam pattern of LCMV and APES are investigated.