Primary-Secondary Users Differences Based Scheduling Algorithm For Cognitive Radio

Nowadays the rapid development of communication technology has brought great pressure to spectrum use. The fixed spectrum allocation can't meet the needs of service requirements. Meanwhile, the imbalance of spectrum use leads to the extremely low efficiency of some authorized spectrum utilization. In order to solve this problem, cognitive radio, which has gradually attracted much attention, is put forward.The paper introduces the key technologies in cognitive radio, such as spectrum detection and spectrum leasing. The radio resources management is fully studied either. The special identities of primary and secondary users bring about the problem that secondary users'QoS can't be reasonably guaranteed. When primary users request to operate in the spectrum secondary users occupied, secondary users need to quit to other free frequency and yet primary users enjoy relatively high priorities to be scheduled. Therefore in order to guarantee users QoS, the fairness and spectrum utilization, the scheduling among primary and secondary users is supposed to be adjusted with comprehensive consideration of the different users'identities and service.In as much as the weakness in the existed scheduling algorithms, a novel primary-secondary users differences based scheduling algorithm (PSUDSA) is put forward. The strategy is adjusted by the different demands on the spectrum scheduling timeliness with meeting interference temperature limits. The users scheduling priorities are determined by the different identities of primary and secondary users, implementation progress, delay urgency and transmission rate requirements. Meanwhile the specific scheduling processes of primary and secondary users' requests, which provide strategies to secondary users'selecting and utilizing spectrum, are proposed.The system-level simulation platform for cognitive radio is designed and implemented. Simulation results show that PSUDSA not only ensures the PUs'quality of service but also improves NDS service'performance, secondary users'QoS and system throughput. Additionally, the novel algorithm makes the resources allocation between PUs and SUs more fair.