信号处理
信號處理
신호처리
SIGNAL PROCESSING
2015年
8期
968-974
,共7页
认知无线电%频谱感知%高斯混合分布%分数低阶矩
認知無線電%頻譜感知%高斯混閤分佈%分數低階矩
인지무선전%빈보감지%고사혼합분포%분수저계구
cognitive radio%spectrum sensing%Gaussian mixture distribution%fractional lower order moments
传统的频谱感知算法因非高斯噪声的干扰,其检测性能严重退化。为抑制实际通信环境中非高斯噪声的干扰,本文提出了一种基于分数低阶矩的空闲频谱检测方法,该方法不需要主用户信号、通信信道和噪声的先验信息。本文采用高斯混合分布拟合非高斯噪声环境,根据中心极限定理及广义二项式定理推导出信道为无衰落和Nakagami衰落时基于分数低阶矩感知算法的检测概率和虚警概率。理论分析和仿真结果表明,在非高斯噪声环境中,基于分数低阶矩感知算法的检测性能明显优于传统的能量检测算法,且采用多天线技术有助于进一步提高感知性能和频率资源的利用率。
傳統的頻譜感知算法因非高斯譟聲的榦擾,其檢測性能嚴重退化。為抑製實際通信環境中非高斯譟聲的榦擾,本文提齣瞭一種基于分數低階矩的空閒頻譜檢測方法,該方法不需要主用戶信號、通信信道和譟聲的先驗信息。本文採用高斯混閤分佈擬閤非高斯譟聲環境,根據中心極限定理及廣義二項式定理推導齣信道為無衰落和Nakagami衰落時基于分數低階矩感知算法的檢測概率和虛警概率。理論分析和倣真結果錶明,在非高斯譟聲環境中,基于分數低階矩感知算法的檢測性能明顯優于傳統的能量檢測算法,且採用多天線技術有助于進一步提高感知性能和頻率資源的利用率。
전통적빈보감지산법인비고사조성적간우,기검측성능엄중퇴화。위억제실제통신배경중비고사조성적간우,본문제출료일충기우분수저계구적공한빈보검측방법,해방법불수요주용호신호、통신신도화조성적선험신식。본문채용고사혼합분포의합비고사조성배경,근거중심겁한정리급엄의이항식정리추도출신도위무쇠락화Nakagami쇠락시기우분수저계구감지산법적검측개솔화허경개솔。이론분석화방진결과표명,재비고사조성배경중,기우분수저계구감지산법적검측성능명현우우전통적능량검측산법,차채용다천선기술유조우진일보제고감지성능화빈솔자원적이용솔。
The performance of the traditional spectrum sensing methods based on the second order statistics (noise environ-ment is assumed to be a Gaussian distribution)may degrade severely due to the heavy tail characteristics of the probability density function (PDF)of the non-Gaussian noise in the actual environment.To this end,we propose a novel fractional lower order moments based detector,which does not require any a priori knowledge about the primary user (PU),channels and noise.The non-Gaussian environment is modeled by the Gaussian mixture distribution.For both non-fading and Nak-agami fading communication channels between the transmitter of the PU and the multiple antennas of the second user (SU),its detection performance in terms of the probabilities of detection and false alarm are derived by using the central limit theorem and the generalized binomial theorem.Analytical and computer simulation results show that the fractional low-er order moments based detector can significantly enhance the spectrum sensing performance over the conventional energy detection with non-fading as well as fading channels in the non-Gaussian noise environments,and the multi-antenna diversi-ty scheme exhibits better detection performance and higher utilization of spectrum resources.