地面數位電視廣播(DVB-T)目前在台灣已成為未來數位電視的主流規格。DVB-T 乃是架構在正交分頻多工(OFDM)系統上。而同步的非理想效應對於OFDM 系統的正交性有很大的影響，失去正交性的OFDM 系統會因為符碼間的干擾(ISI)與子載波間的干擾(ICI)而遭受到破壞。因此如何快速並且準確的完成同步動作便是一個重要的議題。 在本論文中，針對不同的非理想同步效應做介紹，包含符碼邊界位移同步、載波頻率偏移同步以及取樣頻率偏移同步。並且針對處理這些效應的演算法進行比較與分析，以及使用Matlab 與C 語言建立模擬平台。在整數型的載波頻率偏移估測電路採用更為節省記憶體的架構來節省面積，並且對於取樣頻率偏移補償電路採用內插器的方式實現以完成同步電路全數位化的目的。最後將所有的同步 電路進行整合與實現。 The European terrestrial broadcasting standard DVB-T has been adopted an official digital TV speciation in Taiwan. The modulation scheme for DVB-T is orthogonal frequency division multiplexing (OFDM). And the non-ideal effects of synchronization influence the orthogonality between subcarriers very much. And without orthogonality, the OFDM system will introduce Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI), and it will be destroyed by ISI and ICI. Therefore, how to synchronize rapidly and exactly will be the major topic in our system. In this thesis, we will discuss these different non-ideal synchronization effects, including symbol boundary offset, carrier frequency offset and sampling frequency offset. We will compare and analyze the algorithms which detect these non-ideal synchronization effects, and build up a simulation platform by Matlab and C program. In integer carrier frequency offset detection circuit, we reduce chip area by using proposed architecture. And we use interpolator in sampling frequency offset compensation for all digital synchronization circuit. Finally, we integrate and implement all synchronization circuits.
