雙向相位調變混合光纖有線電視/光纖微波傳輸系統

隨著廣受歡迎無所不在的手持設備，人們對於無線和有線傳輸容量的需求越來越大，新世代通訊系統需要高傳輸速率及高頻寬服務來滿足。光纖微波(ROF)、及光纖有線電視(CATV)系統乃是具有發展及應用潛力的通訊系統，用以滿足無線網路和有線光網路需求。光纖微波傳輸系統利用了光纖高頻寬及低傳輸損失的特性，具備高速行動及經濟效益優點；另外，對於用戶而言光纖有線電視系統提供了寬頻服務。在過去有一些研究朝向傳送光纖有線電視或光纖微波；然而對於光纖有線電視/光纖微波混合式傳輸系統的相關研究卻是付之闕如。混合式傳輸系統仍是使用不同的波長在一蕊的光纖裡同時傳送有線電視(CATV)/微波(RF)兩種信號，對於光纖網路而言將可帶來莫大的利基，因為可同時提供電信、網際網路、及有線電視相關服務。不過，如何用最具經濟之效益在一蕊的光纖中同時傳送有線電視(CATV)及微波(RF)信號，至今仍是一大挑戰。在本研究計畫裡，我們提出利用相位調變器具備多波長之特性，用以建構對稱式雙向光纖有線電視/光纖微波混合式傳輸系統；在經過四十公里單模光纖傳輸後，我們將觀察及量測其相關參數特性。不同於強度調變系統，相位調變系統乃是利用相位漂移來記錄光信號狀態，因此具備了高抗雜訊/抗失真、高增益及低雜音指數特性。再加上在使用相位調變器時並不需要額外提供直流電源，使得相位調變器在光纖通訊傳輸系統裡的應用大受青睞。在光信號接收端藉由單一光旁模機制，對於光纖微波應用而言，我們預期將可得到相當低的誤碼率值；而對於光纖有線電視系統來說，同樣的可預期得到良好的載波雜訊比、載波二次合成拍差比、及載波合成三次拍差比參數性能。本研究提出之對稱式雙向混合式傳輸系統提供了電信、網際網路、及有線電視等寬頻整體服務，對於先進光纖網路之應用將極具吸引力。

關鍵字

光纖有線電視；相位調變器；光纖微波

並列摘要

With the ubiquitous popularity of handheld devices, the demands on wireless and wired-line capacity have grown rapidly. The next generation communication systems require large data rate and broadband services highly. Radio-over-fiber (ROF), and fiber optical CATV systems are promising candidates to meet the demands in wireless and wire-lined optical access networks. ROF transport systems have the ability to offer significant mobility, economic advantage, and large capacity due to the characteristics of broad bandwidth and low transmission loss. In addition, fiber optical CATV systems are deployed widely to provide broad bandwidth to subscribers. Nevertheless, hybrid transmission of CATV/ROF combined signals has not been reported. A hybrid two-band transport system that uses different optical wavelength to deliver combined CATV/ROF RF analog signals would be quite useful for fiber networks providing telecommunication, Internet, and CATV services. However, it is a challenge to transmit RF, BB, and CATV signals simultaneously by using one optical fiber in a cost-effective way. In this project, we propose a symmetrically bidirectional CATV/ROF transport system based on lightwave modulated by phase modulators (PMs) with multi-wavelength output characteristic. Transmission performances over a 40-km single-mode fiber (SMF) transmission are studied. Different with the intensity modulation (IM) systems, the PM modulation ones utilize optical phase shifting to record signal state, which provides high robustness to against fiber nonlinearities with high gain and low noise figure. All of these benefits and no DC bias requirement characteristic make it popular in lightwave transport systems. With the help of only one optical sideband and optical single sideband (SSB) schemes at the receiving site, low bit error rate (BER) is expected to be achieved for ROF applications; as well as good performances of carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple beat (CTB) are expected to be obtained for CATV signal. Such a symmetrically bidirectional hybrid three-band transport system would be very attractive for trunk applications in advanced optical fiber transport and distribution networks, for provisioning full services including telecommunication, Internet, and CATV broadband integrated services.

並列關鍵字

Fiber optical CATV ； phase modulator ； radio-over-fiber.

參考文獻

[2] Y. Okamoto, R. Miyamoto, and M. Yasunaga, “Radio-on-fiber access network systems for road-vehicle communication,” IEEE Intelligent Transportation Systems Conf. Proc., 2001, pp. 1050–1055.

[3] A. Chowdhury, H. C. Chien, Y. T. Hsueh, and G. K. Chang, “Advanced system technologies and field demonstration for in-building optical-wireless network with integrated broadband services,” IEEE Journal of Lightwave Technology, Vol. 27, no. 12, 2009, pp. 1920-1927.

[4] Y. T. Hsueh, H. C. Chien, A. Chowdhury, and G. K. Chang “Multiband signals generation and transmission over fiber and air by a novel frequency-doubled, radio-over-fiber architecture without expensive carrier suppression filters,” Optical Fiber Communication of National Fiber Optic Engineers Conference, JTHA35, 2010.

[5] D. R. Goff, Fiber optic video transmission, Burlington: Focal Press, 2003, pp30-281.

[7] G. Keiser, Optical fiber communications, by MC Graw Hill, Fourth Edition.

國際替代計量

雙向相位調變混合光纖有線電視/光纖微波傳輸系統

未授權

主題瀏覽