類比多通道光纖傳輸系統設計

本論文主要用多工器及AID轉換器，將16通道額比信號整合及數位化，再利用1.2Km多模態光纖作為傳輸媒體；接收端利用D/A轉換器及解多工器，將信號分送至各通道上。光纖系統傳輸的方式採用數位曼傲斯特編碼的技術，以減少位元錯誤率。整個系統硬體設計製作包括16通道多工器及解多工器，10位元A/D及D/A轉換器，數位曼徹斯特編碼及解碼器，數位光電轉換器。系統經測試後，輸入輸出之線性度誤差在2%以內，每通道可傳送類比信號頻寬達10KHz，數位光電轉換器速率可達30Mit/S，且傳輸位元錯誤率小於10-9，系統之信號傳輸特性良好。
In this paper, a transmission system with optical fibers is demonstrated. Analog signals up to 16 channels were integrated into a multimode optical fiber. The transmission length is 1.2Km. At receiver end, signals were recovered through an D/A converter and demultiplexed to corresponding channels. During transmission, techniques of Manchester coding were utilized to reduce the rate of bit error. This system includes a 16 channel multiplexer, a 10 bit A/D converter and a Manchester encoder at transmitting end. The corresponding demultiplexer, D/A converter and decoder were set at the receiving end. At both ends of the fiber, E/O and O/E modules were coupled to transfer signals between electrical and optical forms. Several results were obtained (1). Excellent linearity between input and output signals were achieved (with a deviation less than 2%). (2).Signal bandwidth in each channel was up to 10 KHz. (3) The transmission rate was as high as 30 Mbits/sec. (4) The estimated bit error rate was much less than 10-9. The above characterisatics demonstrated that this is an excellent transmission system.