电子科技大学学报2013，Vol.42Issue(3)：355-359,5.DOI:10.3969/j.issn.1001-0548.2013.03.007
认知无线电系统中存在载波频偏的OFDM频谱感知技术
OFDM Signal Sensing Scheme for Cognitive Radio in the Presence of Carrier Frequency Offset
摘要
Abstract
A spectrum sensing technique using the covariance matrix of the discrete Fourier transform (DFT) output of the detector's input vector is proposed.It is found that the covariance matrix is diagonal in the absence of primary user's signal and non-diagonal otherwise.Therefore in the detection procedure,the result can be obtained through comparing the power of the non-diagonal elements of the covariance matrix and the predefined threshold.The probability of distribution functions(PDFs) of the decision metric as well as the threshold and probability of detection in both hypotheses of the signal presence or absence are derived.The numerical results confirm that the proposed algorithm is more robust to the carrier frequency offset compared with the existing methods,and it also enjoys better detection performance.关键词
载波频偏/认知无线电/协方差矩阵/协方差矩阵/频谱感知Key words
carrier frequency offset/ cognitive radio/ covariance matrix/ orthogonal frequency division multiplexing/ spectrum sensing分类
信息技术与安全科学引用本文复制引用
许炜阳,徐婷..认知无线电系统中存在载波频偏的OFDM频谱感知技术[J].电子科技大学学报,2013,42(3):355-359,5.基金项目
国家自然科学基金(61201177):重庆市自然科学基金(CSTC2011JJA0367) （61201177）
