认知无线电中基于感知时间和K秩准则的优化  

Joint Optimization Based on Sensing Time and K-rank Criteria in Cognitive Radio

作　　者：李红[1] 齐丽娜[1] 

机构地区：[1]南京邮电大学通信与信息工程学院,江苏南京210003

出　　处：《计算机技术与发展》2015年第12期186-190,共5页Computer Technology and Development

基　　金：国家"973"重点基础研究发展计划项目(2013CB329005);国家自然科学基金资助项目(61471201)

摘　　要：认知无线电系统中,通过次用户间的协作频谱感知可以大大增加系统的检测概率,但同时也增加了系统的能量消耗。为了提高认知无线电系统的综合性能,文中分别对系统的错误概率和能量效率进行优化。文中次用户采用K秩融合准则来进行协作,所以影响系统性能的参数可以是K、参与协作的次用户数N和感知时间τ。而优化问题可以分为两个阶段:第一阶段,给定τ,通过使错误概率最小来得到最优的K和N;第二阶段,给定K和N,通过使能量效率最小来得到最优的τ。文中利用数学推导,证明了两个优化问题均存在最优值,最后再利用联合迭代算法可以得到综合最优的K、N和τ。仿真结果验证了之前的理论分析,并表明在最优参数下系统的综合性能明显提高。Although cooperative spectrum sensing in cognitive radio networks can greatly increase the detection probability,it increases the energy consumption of the system. In order to improve the comprehensive performance of the system, the false probability and the energy efficiency is optimized. In this paper,consider the case where the secondary users cooperatively sense a channel using K-rank criteria （ K -out-of - N fusion rule） to determine the presence of the primary user, so the performance of the system depends on K, N and sensing time （ r ）. The process of solving the optimization problem is divided into two stages in this paper. In the first stage, given the sensing time, K and N are optimized by minimizing the false probability. In the next stage, given K and N ,the sensing time is optimized by mini- mizing the energy efficiency. In this paper, two optimization problems are proved to have the optimum value by employing the mathemati- cal derivation. The optimal K, N and through the joint iterative algorithm can be obtained. Computer simulations verify the theory analy- sis and show the significant improvement in the performance of system when the parameters are jointly optimized.

关 键 词：认知无线电 频谱感知 感知时间 能量效率 

分 类 号：TN911.1[电子电信—通信与信息系统]