Abstract: As the spectrum resource is in great shortage currently, cognitive radio has emerged to efficiently use the idle spectrum. As one of its applications, IEEE802.22 has opened the VHF/UHF TV band to cognitive radio users. In order to utilize the TV band properly, it needs to detect the signal first. With the popularity of digital TV, the spectrum sensing of digital television signal becomes particularly important. The sample rate of traditional Nyquist sampling is high, which wastes space and time. Since TV signal is sparse in the frequency domain, compressive sensing can perfectly recover the original signal with less points by random sampling. In view of this, compressive sensing and energy detection are applied to the spectrum sensing of digital TV signals, it improves spectrum efficiency.

Key words: compressive sensing, Digital Video Broadcasting-Terrestrical（DVB-T）, spectrum sensing

摘要： 目前频谱资源紧张，有效利用空闲频谱的认知无线电技术应运而生，IEEE802.22开放了VHF/UHF电视频段供认知无线电用户使用。为了合理利用电视频段，首先要对电视信号进行检测，随着数字电视的普及，对数字电视信号的检测尤为重要。传统奈奎斯特采样采样率高，耗费空间和时间，而电视信号在频域具有稀疏性，应用压缩感知技术能以随机采样的方式用更少的数据点来很好地恢复原始信号。鉴于此，应用压缩感知技术，采用能量检测法对数字电视信号进行频谱检测，提高频谱利用率。

关键词: 压缩感知, 地面数字电视广播（DVB-T）, 频谱检测