基于变步长序贯压缩的频谱快速感知算法  

Spectrum Sensing Algorithm Based on Variable Step-Size Sequential Compressed Sampling

作　　者：张恒龙[1,2] 宋晓勤[1,2] 朱勇刚[3] 涂思怡 

机构地区：[1]江苏省物联网与控制技术重点实验室(南京航空航天大学),南京210016 [2]南京航空航天大学电子信息工程学院,南京210016 [3]总参第六十三研究所,南京210007

出　　处：《数据采集与处理》2015年第4期839-847,共9页Journal of Data Acquisition and Processing

基　　金：国家自然科学基金(61301103)资助项目;国家自然科学基金(61401505)资助项目;江苏省自然科学基金(BK20130069)资助项目;中国博士后基金面上项目(2012M521853)资助项目;江苏省博士后科研资助计划(1201076C)资助项目;"物联网与控制技术"优势学科资助项目

摘　　要：对信号稀疏度未知甚至时变的频谱感知应用场景,将自适应思想与序贯压缩频谱感知技术相结合,提出了一种可变步长序贯压缩频谱快速感知算法。新算法建立了下一次判决所需观测值数目步长因子与当前对数似然比距门限距离之间的函数关系,克服了现有的序贯压缩检测算法以固定步长增加观测值的不足。分别以分段函数和抛物线函数为步长因子调整规则进行理论分析和仿真实验。仿真结果表明:与现有的序贯压缩检测算法相比,变步长算法具有检测速度快、观测值数目少和计算复杂度小等优点。The signal sparsity is often unknown,or even changed with time in spectrum sensing.Therefore,a variable step-size sequential compressed detection algorithm is proposed by combining the adaptive theory with the sequential compressed spectrum sensing technology.The functional relationship is established between step-size factor of the next needed measurement numbers and current distance from the likelihood ratio and the detection thresholds.In addition,the shortcoming of the fixed step size of the measurement increment in the existing sequential compressed sensing is overcomed in the proposed algorithm.Theoretical analysis and computer simulations are conducted by introducing the rules of step size adjustment with piecewise function and parabolic function,respectively.Simulations prove that,the proposed algorithm has the faster detection speed,less measurements number and lower computational complexities,compared with the existing sequential compressed detection scheme.

关 键 词：宽带频谱感知 压缩采样 变步长 序贯压缩检测 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]