An adaptive scheduled transmission strategy for multimedia services in WCDMA systems

Since the capacity in WCDMA system is limited by interference, an efficient radio resource mechanism is important to enhance overall performance. Previous researches have shown that uni-access mode is an efficient way to reduce intracell interference caused by other transmitting users, and hence higher performance is attained compared to traditional multi-access mode. However, due to the constraint in the practical system, a single user might not fully utilize the available bandwidth. Consequently, the system capacity as well as throughput will be not optimized. This paper introduces a novel Transport block size based Adaptive Scheduling Scheme (TASS) that utilizes radio resource more efficiently and sufficiently. Different from both uni-access and multi-access mode, the TASS can be seen as a mixed version of them called hybrid-access mode. Via the transmission strategy, less power is required while achieving equivalent throughput and thus higher performance is expected. In order to guarantee the delay time of each user, the scheduling algorithm earliest deadline first (EDF) is applied. As a result, the TASS is suitable for real-time traffics. The experiment results demonstrate that this new transmission strategy carries advantages in system capacity, average delay and overall throughput.