认知无线电网络频谱聚合策略的性能优化

Performance Optimization of Spectrum Aggregation Strategy in Cognitive Radio Networks

为了有效提高认知无线电网络频谱共享的性能,综合考虑了集中控制模式下的数据传输质量及信道利用率,研究了基于主用户的频谱聚合策略.针对一个聚合频谱中的多个信道,面向次级用户建立具有多服务台且传输过程可同步中断的离散时间排队模型.使用矩阵几何解方法,求解出主用户数据包阻塞率、次级用户数据包平均延迟以及信道利用率等性能指标的表达式.实验结果表明,在设置频谱聚合容量时,不同性能指标之间存在折中关系.通过建立成本函数,给出了频谱聚合容量的设置方案,实现了认知无线电网络频谱聚合策略的性能优化.

In order to effectively improve the spectrum sharing performance in cognitive radio network,considering the transmission quality and channel utilization with centralized control mode,the spectrum aggregation strategy for primary users is investigated. For an aggregated spectrum consists of multiple channels,considering that primary users have higher priority to secondary users,a discrete time queueing model with multiple servers and synchronous transmission interruption is built. Using the method of matrix geometric solution,the steady state distribution of the system is given. Accordingly,performance measures in terms of blocking ratio of primary users,average delay of secondary users and channel utilization are derived. Experimental results show that when setting the spectrum aggregation capacity,there is a trade-off between different performance measures. By establishing a system cost function,the scheme for setting spectrum aggregation capacity is carried out,and the spectrum aggregation strategy in cognitive radio networks is optimized.