认知无线电OFDM系统中符号内相关频谱感知算法  

In-Symbol Correlation Spectrum Sensing Method for OFDM Systems in Cognitive Radio

作　　者：段鹏[1] 何明一[1] 薛敏彪[1,2] 党群[2] 

机构地区：[1]西北工业大学电子信息学院,西安710072 [2]西北工业大学365研究所,西安710065

出　　处：《计算机科学》2011年第4期93-96,共4页Computer Science

基　　金：国家"863-705"主题项目(2004AA752022);陕西省2010年度工业攻关项目(2010K06-09)资助

摘　　要：提出一种利用导频的周期性在符号内进行相关运算的OFDM信号频谱感知算法。该方法首先将接收序列分成两个子序列,利用导频的周期性在每个子序列内进行叠加平均,以降低噪声方差;然后,将两个子序列进行相关运算,降低时变信道对相关值的影响。同时,通过分析相关值的期望与方差,进一步验证了新方法在时变信道下的有效性。仿真结果表明:新频谱感知方法在时变信道下明显优于传统方法,且减少了参与计算的符号个数,同时计算复杂度较低。Based on characteristic of periodic sequence,a novel spectrum sensing method that takes the correlation calculation was proposed in OFDM systems.Firstly,divided the received sequence into two part,and took average calculation respective to reduce the noise variance in an OFDM symbol,then used the two sub-sequences to take the correlation calculation,the influence brought by time-vary channel could be reduced.And the expectation and variance of correlation value were analyzed,verifying the new method was of validity.The experiments showed that the new method outperforms the traditional method in time-vary channel,reduces the number of symbols involved in the calculation,and has the low calculation complexity.

关 键 词：认知无线电 OFDM 频谱感知 时变信道 时域相关运算 

分 类 号：TN911[电子电信—通信与信息系统]