歐洲電信標準組織(ETSI)所制定的地面波標準(DVB-T)是世界上最普遍使用的數位電視地面廣播系統。然而此系統是早期所訂定,頻寬使用效率對於近年來高畫質電視(HDTV)的商業需求已不符合需求,進而產生了第二代歐規數位電視地面廣播系統(DVB-T2),有鑒於第二代數位電視之重要性,而目前實作之文獻較少,故本論文依照DVB-T2(ETSI EN 302 755)之規範,將通道解瑪及解調變的技術以軟體方式實現,我們以實際第二代數位電視之中頻訊號,自行撰寫相關程式進行解碼,包括取樣頻率轉換、正交分頻多工的同步與解調變、通道估測與等化,以及解交錯、BCH、低密度奇偶檢查碼(LDPC)…等。我們解碼進行到最後,可得到MPEG-2 Transport Stream,並且利用影音播放軟體播放其聲音及影像,確認程式之正確性。
The European standard for digital video broadcasting over terrestrial (DVB-T) is the most popular system in the terrestrial digital TV worldwide. To understand the technical details of the standard (ETSI EN 302 755), we decide to implement the DVB-T2 demodulator and channel decoder in software. The program we write includes the following functions: sampling rate conversion, synchronization and demodulation for orthogonal frequency division multiplexing (OFDM), channel estimation and equalization, de-interleaving, BCH, Low-density parity-check code (LDPC), etc. Using the digitized intermediate frequency (IF) sample as the input, our program produces a MPEG-2 Transport Stream (TS). The TS can be decoded using a commercial media player. Thus, the correctness of our program is fully verified.