Research On Fast Dynamic Channel Allocation Algorithm In TD-SCDMA System

Dynamic Channel Allocation (DCA), one of the key technologies of TD-SCDMA, has the advantages of suppressing the interference, minimizing the channel reuse distance, thus utilizes the finite radio resource efficiently and improves the capacity of the system. In TD-SCDMA system, the fast DCA technology distributes wireless channel resources to the users that apply to access the system, and adjust the allocated resources according to the state of the system.Based on domestic and international fast DCA algorithm, this paper studies the fast DCA technology in TD-SCDMA system.In order to improve the channel utilization and balance the channel using between the handoff calls and the new calls. A channel reservation strategy is proposed in this paper, which solves the multi-service resource allocation problems, provides the reserved channels for handoff calls and allows the new calls to borrow the reserved channels in a certain probability. The simulation results showed that the strategy can not only limit the deterioration of the new call blocking probability caused by the channel reservation, but also reduce the overall call blocking.With the increasing demands of multimedia services in personal communication, we should consider the different multimedia data services besides the real-time voice services.For this requirement,a dynamic channel allocation scheme based on handoff reserving and new call queuing is presented. The scheme not only considers the priorities between services, giving real-time business a higher priority; but also considers the priorities between different real-time services and non-real-time services. As a result,handoff calls has a higher priority than the new calls and the ordinary data services owns a higher priority than the best-effort data services. Based on the result, we can see that the blocking probabilities of the new calls and the handoff calls are both reduced when the the data services intensity is high, the blocking probability of the ordinary data services is increased and the overall system performance is improving.