| 摘要: | 實驗室以務實軟體定義無線電(Software-defined Radio,SDR)來實現DVB-T接收機，結合FPGA(XC7A200T)及射頻模組(AD9361)完成軟體定義無線電平台，本論文設計基頻電路來進行DVB-T訊號解調，基頻接收機需要的模組包括降頻取樣、時間同步、頻率同步、快速傅立葉轉換、通道估測等化、符元解交錯器、軟式決策、位元解交錯器、迴旋碼解碼、外部解交錯器、里德所羅門碼解碼、解亂碼器，將解調解碼得到之MPEG-2傳輸封包資料流用VLC多媒體播放器播出。
先實錄訊號以Matlab進行解調，再使用硬體描述語言設計基頻電路，用iSim模擬電路時序後，再以軟體定義無線電平台實錄訊號驗證其硬體功能，經過解調解碼後，便能夠得到MPEG-2(Moving Picture Experts Group, MPEG) Transport Stream，將之播放以驗證接收機之成果。
;Our laboratory use Realistic Software-defined Radio platform to implement Digital Video Broadcasting Terrestrial(DVB-T) receiver. We combine FPGA and Radio Frequency module(AD9361) to finish SDR platform. In this thesis, we design baseband receiver for demodulation and Decoder DVB-T signal. This baseband receiver needs the digital signal processing units which are down sampling, time synchronizer, frequency synchronizer, Fast Fourier Transform processor, channel estimator, channel equalizer, symbol de-interleaver, soft decision, bit de-interleaver, Viterbi decoder, packet synchronizer, outer de-interleaver, Reed Solomon decoder, de-scrambler. The signal which is under demodulation and decoder is MPEG-2 Transport Stream, and we can play the video via VLC player.
First, we record DVB-T signal on Matlab and demodulate the signal. Furthermore, we design baseband digital signal processing units by using Verilog hardware description language and verify with iSim. Then, the real-time hardware is implemented and verified with SDR platform. After it is under demodulation and decoder, we are able to get MPEG-2 Transport Stream. We could play this Transport Stream to verify baseband receiver’s result. |
