This article proposes a hybrid multiple access (HMA) transmission strategy that integrates the traditional multi-access mode and the novel uni-access mode for WCDMA downlink. For better multiplexing of services with different quality requirements, this paper also proposes a quality based admission control policy and a scheduling scheme to construct an overall system for evaluation. Furthermore, a throughput optimization extension considering both intra-cell and inter-cell interference for the HMA is presented. In the simulation study, it is shown that the HMA outperforms the CDMA system with better GOS, lower delay, lower BER and higher throughput where last three aspects of improvement are gained by uni-access transmission mode. We observe that the HMA provides more significant improvements when the system load is higher.