Downlink beamforming and data rate adaptation applied for packet data transmission over the UMTS dedicated channel

In this paper system level simulation results from the performance evaluation of applicable downlink beamforming concepts for UMTS are presented. For the first time the combination of beamforming and packet data services over UMTS dedicated channels in conjunction with data rate adaptation is investigated. The main focus of this paper is to assess realistic system capacity gains of the different beamforming concepts regarding UMTS specific conditions. 

Special focus is paid on the comparison of 3/6 sector scenarios with fixed beam switching (FBS) and beam pointing (BP). When applying FBS and BP with 4 antenna elements (4 beams for FBS) a cell throughput gain of about 180...190 % is reached compared to 3 sectors scenario. This gain is coming along with a reduction of the required downlink transmit power dedicated to a specific user. Moreover, due to the lower complexity of the FBS concept and the comparable capacity gain, FBS is preferred to BP