认知无线电系统中信道搜索优化算法  

Optimization algorithm for channel searching in cognitive radio system

作　　者：叶军[1,2] 朱琦[1,2] 酆广增[1,2] 

机构地区：[1]南京邮电大学江苏省无线通信重点实验室,江苏南京210003 [2]南京邮电大学教育部宽带无线通信与传感网技术重点实验室,江苏南京210003

出　　处：《电路与系统学报》2011年第5期76-83,共8页Journal of Circuits and Systems

基　　金：国家自然科学基金(61171094;61001077);国家重点基础研究发展计划资助(2007CB310607);国家科技重大专项(2011ZX03001-006-02;2011ZX03005-004-03)

摘　　要：频谱检测是认知无线电中一项至关重要的技术。次用户通过周期性检测可获得信道状态的先验信息并借助该信息确定检测算法快速发现空闲信道,从而使搜索到空闲信道的时延大大降低,使次用户自身业务的平均中断概率最小化。本文综合考虑信道空闲概率和信道利用率两个因素提出了空闲信道搜索优化算法并且推导了搜索到第一个空闲信道的平均时延表达式。通过仿真发现:搜索到第一个空闲信道平均时延的理论与实际仿真非常接近,验证了理论推导的正确性;采用本文算法搜索信道的平均时延要比随机搜索方法小得多。本文还讨论了等待时间对平均时延的影响,存在一个最优等待时间使搜索到第一个空闲信道的平均时延最小。Spectrum detection is a critical technology in cognitive radio.Secondary user（CR） can get the prior information about primary user using channels by periodically detecting,which can guide the detection algorithm to find idle channels quickly and greatly reduce the delay time and minimize the CR user＇s average interruption probability.This paper develops an optimization algorithm for searching an idle channel by considering idle probability and utilization probability of a channel,then we derive the expressions of average delay that CR user searches the first idle channel.It is observed from the simulation that simulated and theoretical curves exhibit the same trend and their values are almost the same,which verify the correctness of theoretical analysis in this paper.Comparing random searching method,our algorithm can greatly reduce the searching delay.The impact of waiting time to average delay is discussed.It is found that there is an optimal waiting time that minimizes the average delay of CR user searching the first idle channel.

关 键 词：认知无线电 频谱检测 信道空闲概率 信道利用率 平均时延 等待时间 

分 类 号：TN929[电子电信—通信与信息系统]