On the use of constrained beamformer for the improvement of the bit-error-rate of CDMA based Mobile Communications Systems

The performance enhancements that can be achieved by employing constrained beamformers in code division multiple access cellular radio systems is investigated in this paper. It is shown in the paper which improvements on the bit error rate of the uplink channel (link from the mobile units to the base station) are possible using constrained beamformers. We use the Gaussian technique to find an accurate approximation to the probability of data bit error developed for direct-sequence spread-spectrum multiple-access packet radio systems. Analytical results and simulations are presented which demonstrate that constrained beamformers at the base station can improve the revers channel performance. Upper and lower bounds for the improvements are given in the paper.