基于轮询调度的频谱接入机制研究

Research on Spectrum Access Mechanism Based on Polling Scheduling

动态频谱接入是提高无线电频谱利用率的有效方案,基于轮询控制的接入机制易于实现对频谱资源的有效利用和合理分配。提出了一种授权用户和认知用户分别采用穷尽式服务和损失制服务的轮询排队模型,采用嵌入马尔可夫链和概率母函数的分析方法,通过求解平衡状态下系统的平稳分布,得到了平均排队队长、信道利用率和强制中断率的关键参数解析结果。数值分析和仿真实验表明,该机制提高了系统排队性能、有效利用了频谱空洞,在以数据业务为中心的认知无线网络中有潜在应用。

Dynamic spectrum access is an effective way to improve the spectrum utilization. The spectrum access mechanism based on polling control tends to realize the effective utilization of spectrum resources and rational allocation. A novel polling queuing model, in which the authorized users employ exhaustive service while the cognitive users employ loss service, was proposed. Based on the analysis method of embedded Markov chain and probability generating function, the key parameters of average queue length, bandwidth utilization and forced termination probability were obtained through solving the stationary distribution of equilibrium state. Numerical analysis and simulation results show that the mechanism improves the queuing performance and the bandwidth utilization of spectrum holes, and reveal its potential application in cognitive wireless network for data services.