认知无线网络中集中式信道搜索策略的研究

摘要

认知无线网络中,认知用户利用授权用户暂时不用的信道传输数据,认知用户对空闲信道的搜索策略成为了认知无线网络效率提高的关键问题之一.将哈希算法应用于认知无线网络的信道搜索过程中,给出了一种面向认知用户的集中式信道搜索策略HSS (Hash-SU-Search).建立了带有两类顾客的离散时间排队模型,给出了系统的信道利用率及平均搜索次数等性能指标的表达式.通过数值实验,将HSS信道搜索策略与传统的顺序信道搜索策略进行了比较,验证了HSS的有效性.%In cognitive radio networks, the secondary users utilize the channel unused temporarily by the primary users to send packets. The idle channel search scheme for the secondary users becomes one of the key problems for improving the efficiency of the cognitive radio networks. The Hash algorithm is applied to the channel searching process of cognitive radio networks, and a central channel search scheme called HSS (Hash-SU-Search) for the secondary users is offered. A discrete-time queuing model with two classes of customers is built, the formulas for the performance measures in terms of the channel utilization and the average searching times are given. By numerical experiments, the HSS is compared with the traditional sequential channel search scheme, and the effectiveness of HSS is verified.