在這篇論文中將展示二種在數位電視廣播系統的基頻器接器的同步迴路。其 中一個是符元邊界偵測，而另一個是載波頻率偏移回復迴路。在符元邊界偵測的 部份，我們將介紹一種修改過的最大可能偵測預測。我們修改了一些實現的方 法，使得些同步手段可以被現代的超大型積體電路科技給實現，而且有著較低的 複雜度。這也會為我們帶來二個好處，就是縮小記憶體的使用量，另外一個就是 有比較快的偵測速度。 在載波頻率偏移回復的部份，我們整合了三種不同的演算法，分別是最大可 能偵測、防護頻帶功率偵測(Guard Band Power Detection)和後快速傅立葉轉換 (post-FFT)載波頻率追蹤。加上我們適當的修改之後，這些演算法可以使用部份 跟符元邊界相同的硬體，只是要加上一點點額外的控制電路(例如有限狀態機)。 在加上這兩個修改過的演算法之後，這個基頻接受器可以抵抗符元邊界偏移與載 波頻率偏移而不需要很大的硬體成本。 In this thesis, we demonstrate two synchronization loops in DVB-T baseband receive. One is symbol boundary detection and the other is carrier freqeuncy offset recovery loop. We introduce a modified maximum likelihood estimation in boundary detection loop. We modify some implemation methods, thus it can be realized by morden VLSI technology with less complexity. And it has two benefits less memory usage and fast detection speed. In carrier frequency offset recovery, we integrate three different algorithms. Which are maximum likelihood estimation, guard band power detection and post-FFT carrier freqeuncy tracking. By applying our modification, these algorithms can sharing the same hardware of boundary detection. Thus just a little additional circuits are needed (ex. finite state machines). The baseband receiver can resist symbol boundary offset and carrier freuquency offset by using these two modified algorithms without heavy implemation cost.
