Hybrid CATV/ROF Transport System with Colorless Remodulation Technique

混合式光纖有線電視／微波傳輸系統建構於無色光源之再調變技術

黃慶修

《光學工程》 113期 (2011/04) Pp. 36-42

https://doi.org/10.30011/OE.201104.0006

摘要

本文提供兩個架構，同時傳輸兩種訊號，分別爲強度調變的光纖有線電視及相位方式調變的微波訊號。在第一個架構中，提出了一個全雙工的系統架構。混合式的光纖有線電視／微波傳輸系統中，雷射直接調變多載波的電視訊號，經光纖傳送，再經過相位調變器，調變另一數位訊號回到頭端。在解調變的元件，使用一延遲器，來解調回強度訊號。在已測得的載波雜訊比、載波合成二次拍差比、載波合成三次拍差比及誤碼率當中，皆符合有線電視及光纖微波系統的性能要求。在第二個架構中，提出的方案為同時傳輸光纖有線電視及光纖微波訊號經由光纖傳輸至用戶端。在用戶端的部份，以一個偏振片來解調，把相位訊號轉成強度訊號。系統性能方面，有線電視及微波訊號，仍舊符合規範。

關鍵字

直接調變 ； 外部調變 ； 光纖有線電視 ； 光纖微波 ； 相位調變

並列摘要

Two fiber-optic transport systems are developed to simultaneously transmit CATV signal in amplitude domain and ROF signal in phase domain. The first architecture, we proposed and demonstrated a full-duplex transport system. We study hybrid CATV/ROF scheme using cost-effective directly modulated laser to generate downstream Multi-carrier CATV signal and provide upstream radio signals using a phase remodulated technology. For demodulator, we utilize a delay line (DI) to transform the phase signal to intensity signal. The obtained carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple beat (CTB) and bit error rate (BER) performance, not only satisfy the fiber optical CATV requirements, but also meet the high quality ROF demands over single-mode fiber (SMF) transmissions. The Second architecture, we proposed and investigated, is simultaneously directly modulating CATV and phase remodulating ROF signal for Optical Network Unit (ONU) via the same SMF. At the ONU, the phase signal is converted into intensity signal by a polarizer. Good performances of CNR/CSO/CTB and high extinction ration (ER) and low BER were obtained.

並列關鍵字

Directly modulated ； externally modulated ； fiber optical cable television ； radio over fiber ； phase modulation