中文摘要：

分析了认知无线电中的频谱感知技术。对加性白高斯噪声信道下匹配滤波器检测法和能量检测法进行了研究，并比较了能量检测法下认知用户单独检测、合作检测以及采用多样性技术来检测第一用户的性能。仿真结果表明：在低信噪比情况下，匹配滤波器具有良好的检测性能；当信噪比大于0dB时，采用能量检测法能够检测各种信号；认知无线电用户之间合作检测和采用多样性技术能够提高能量检测法的可靠性。

英文摘要：

Spectrum sensing technologies in cognitive radio are minutely analyzed. By adding white gauss noise （AWGN） channels, matched filtering and energy detection are studied. The detection performance and the improvement of sensing spectrum are compared by cooperation and diversity schemes. Computer simulation results show that matched filtering can detect weak signals when SNR is lower. Energy detection is simple and efficient when SNR exceeds 0 dB. Cognitive radio users collaborated with each other could improve reliability of energy detection.