在現代的無線通訊中，正交分頻多工系統 (Orthogonal Frequency-Division Multiplexing, OFDM) 已經被廣泛使用於各種裝置中-例如數位電視廣播系統。在這種情況下，當然也就產生了一些問題，其中就是頻帶使用效率的部分-如何去提高頻帶的使用效率是一大問題。為此科學家提出了感知無線電的理論(Cognitive Radio)來改善這些問題。感知無線電主要可分為頻譜檢測(Spectrum Sensing)、電源控制(Power Control)、頻帶分配(Spectrum Management) 三大部分。本篇論文主要屬於頻譜檢測的部分，並著重在第二代數位電視廣播系統 (DVB-T2) 上。藉由分析其特殊的領航訊號特性，來檢測其頻譜。 In modern wireless communications, Orthogonal Frequency-Division Multiplexing is widely used in a variety of systems such as digital video broadcasting. It turns out that the problem of how to improve the spectrum efficiency is mentioned for real applications. To solve this problem, the cognitive radio schemes are rapidly increasing in the literature. There are three main categories in cognitive radio: spectrum sensing, power control, and spectrum management. This paper studies the spectrum sensing method for DVB-T2 based on pilots to be used with a short cyclic prefix length. The DVB-T2 spectrum is sensed through the specific pilot patterns that are designed in DVB-T2.
