Downlink throughput enhancement by combining packet scheduling with a simple power control scheme in CDMA data networks

CDMA data networks such as the Qualcomm High Data Rate (HDR) are proposed in the midst of evolving to the 3rd generation wireless networks. The downlink transmission power is fixed for all users in HDR systems unlike IS-95 systems that are designed for the voice service only. The HDR systems endeavour to utilize the bandwidth efficiently by selecting the optimal transmission rate for the current channel state, which yields similar effects to the power control. There remains the possibility, however, to get additional benefits from the power control. Inter-cell interference can be alleviated by reducing the transmission power to the users close to a basestation (BS) without sacrificing their transmission rates. We propose a simple two-level power control scheme that uses the full power and the reduced power alternately, and combine it with some packet scheduler to increase the system throughput. Simulation results show that the cell throughput has been improved by about 10-20%.