Performance of WCDMA downlink shared channels

In order to avoid downlink channelization code shortage, a DSCH bas been specified for WCDMA Release 99 system, and has been designed for enabling high data rate packet transmission. Further, WCDMA Release 5 introduces HSDPA to realize higher speed data rate together with lower round-trip times. In this paper, the performance of the downlink shared channel of Release 99 and HSDPA systems has been presented and compared. The system level simulation results were obtained using a dynamic system simulator. The simulator includes all relevant radio characteristics, WCDMA/HSDPA functions, and realistic models of the downlink traffic generated by web browsing and video streaming users. The results show that, under web browsing traffic, the HSDPA concept provides a 200% higher capacity gain than Release 99 DSCH and it goes to triple the service throughput when system load is increased. Moreover, the HSDPA concept offers a 50 % higher video capacity gain than Release99 DSCH.