桂林电子科技大学学报
桂林電子科技大學學報
계림전자과기대학학보
JOURNAL OF GUILIN UNIVERSITY OF ELECTRONIC TECHNOLOGY
2015年
2期
105-109
,共5页
频谱检测%静默期%能量检测%循环平稳特征检测%双门限
頻譜檢測%靜默期%能量檢測%循環平穩特徵檢測%雙門限
빈보검측%정묵기%능량검측%순배평은특정검측%쌍문한
spectrum detection%quiet period%energy detection%cyclostationary feature detection%double threshold
针对传统的能量检测需要静默期且低信噪比下检测概率不高的问题，提出适用于无静默期的双门限频谱检测算法。利用 OFDM信号循环前缀的特征消除认知用户干扰，以构建无静默期的能量检测；设置优化门限与固定门限，通过比较二者大小，提出高信噪比下使用优化门限的能量检测方法以及低信噪比下结合能量检测与循环平稳特征检测的联合频谱检测方法，消除静默期，以提高低信噪比下的检测概率。数值分析表明，与传统能量检测算法相比，该算法在低信噪比下的检测概率提高15%~30%，同时在高信噪比下的虚警概率降低5%。
針對傳統的能量檢測需要靜默期且低信譟比下檢測概率不高的問題，提齣適用于無靜默期的雙門限頻譜檢測算法。利用 OFDM信號循環前綴的特徵消除認知用戶榦擾，以構建無靜默期的能量檢測；設置優化門限與固定門限，通過比較二者大小，提齣高信譟比下使用優化門限的能量檢測方法以及低信譟比下結閤能量檢測與循環平穩特徵檢測的聯閤頻譜檢測方法，消除靜默期，以提高低信譟比下的檢測概率。數值分析錶明，與傳統能量檢測算法相比，該算法在低信譟比下的檢測概率提高15%~30%，同時在高信譟比下的虛警概率降低5%。
침대전통적능량검측수요정묵기차저신조비하검측개솔불고적문제，제출괄용우무정묵기적쌍문한빈보검측산법。이용 OFDM신호순배전철적특정소제인지용호간우，이구건무정묵기적능량검측；설치우화문한여고정문한，통과비교이자대소，제출고신조비하사용우화문한적능량검측방법이급저신조비하결합능량검측여순배평은특정검측적연합빈보검측방법，소제정묵기，이제고저신조비하적검측개솔。수치분석표명，여전통능량검측산법상비，해산법재저신조비하적검측개솔제고15%~30%，동시재고신조비하적허경개솔강저5%。
In cognitive radio,quiet period is usually required on the traditional energy detection and the corresponding detec-tion probability is not high in low signal-to-noise ratio (SNR).To avoid quiet period and improve the detection performance, a spectrum sensing algorithm based on double threshold is proposed.First,the cyclic prefix of OFDM (orthogonal frequen-cy division multiplexing)signals is applied to eliminate the interference of cognitive user by which energy detection without quiet period is implemented.Meanwhile,optimized threshold and fixed threshold are used.Comparing two thresholds,the energy detection of optimized threshold is adopted in high SNR,and a joint detection of the cyclostationary feature detection and energy detection is used in low SNR.Finally,quiet period is eliminated and detection performance is increased in low SNR.Numerical results show that compared with energy detection,the detection probability is improved 15%-30% and the false alarm probability is decreased 5%.
