Transmit beamforming and power control in downlink channels of amulti-rate CDMA communication system

摘要

This paper studies the benefits of combining beamforming and powercontrol in the downlink channel of a CDMA communication system employinga variable length orthogonal spreading code (OLSC). It is demonstratedthat the high data users cause significant interference to the low datausers if we do not employ beamforming. Furthermore, if we performbeamforming for both types of users, most of the gain we achieve is dueto the high data users if the total power of the high data users is muchhigher than that of the low rate users. Thus we may reduce thecomputational requirement significantly if we perform beamforming forthe high data users only with a small increase in total power