全雙工的光纖有線電視與微波傳輸系統

近期在微波傳輸系統中，最引起關注的技術是提供豐富的服務，同時為客戶提供語音、網路和電視影音等多重服務。為了實現這個目標，必須在單一的頭端提供多組的電光發射器，每一組的電光發射器包含一個雷射二極體、外部調變器、本地震盪器及混頻器。這表示一個頭端需要多個雷射二極體，這將大幅提高系統的成本。因此在本論文中我們提出一具經濟效益之架構，其中包含一顆單縱模的分佈回授布雷格雷射、一台無線訊號產生器及一個波長選擇器進而取代數個電光發射器之陣列。本架構除了能簡化整體系統的複雜度之外，亦可降低建構成本，達到低價格、高標準的目標。由於光纖通訊蓬勃發展，新成立的有線電視系統為了提高市場佔有率，需向電信固網業者承租光纖，然而，這些光纖主要用來傳送類比的電視訊號。所以，當光纖數量不敷使用時，電信業者則必須面對可同時載送數家有線電視業者之電視訊號。本論文提出全雙光的有線電視傳輸系統，即同時載送強度調變的光纖有線電視訊號與相位調變的微波訊號。其中相位調變器不像強度調變器須供給額外的偏壓，再者，相位調變器抗非線性能力也比強度調變器來的佳，不只能簡化傳輸端的系統，也可減少非線性效應的影響，大幅提高訊號的品質。

關鍵字

光纖微波系統；光纖有線電視；多波長載波抑制；全雙工

並列摘要

Radio-over-fiber (ROF) technologies have recently attracted abundant attentions to provide triple-play wireless services for residential and business clients. The triple-play, also known as digital convergence, which means the telephone network, internet and cable television joint development of the three, while providing customers with voice, internet and video television, such as multiple services. To achieve this objective, a central station (CS) will need multiple sets of electrical-to-optical (E/O) transmitter to provide suitable optical carriers and to up-convert baseband signals into radio frequency (RF) range for various BSs, respectively. Each set of E/O transmitter including a laser diode (LD), an external modulator (EM), a local oscillator (LO) and a mixer. This means that a CS will need multiple LDs, EMs, LOs and mixers to support various base station (BS) transmissions in RoF systems. In the structure of our advance, multiple fixed frequency-spacing carriers are generated by directly modulating a sinusoidal RF signal with a DFB laser, and consequently a wavelength selector is employed to separate and route every two carriers to different E/O converters for different BSs. The vigorous development of fiber-optical communication caused the established newly cable system in order to increase market percentage. So they should rent the optical fiber by the network operators. This fiber is mainly used to transmit analog TV signal. If the number of optical fiber will be insufficient, the operator must face the thing that plenty tenants could employ in the finite fiber situation. This proposed full-duplex optical cable transmission system, which contained both intensity modulated in CATV signals and phase modulated with microwave signals. The multi-carrier CATV signals was modulated directly and then through a single mode fiber. The re-use signal of upstream was modulated by phase modulation. The radio signal was demodulated by the delay line interferometer in the Rx, the signals with phase modulated was transformed the signal of the intensity modulated. Phase modulator unlike the intensity modulator which must supply additional bias voltage, it also could reduce the non-linear effect. The experiment not only simplified the transmission system but also reduce the non-linear effect. It could increase the signal quality enormously.

並列關鍵字

Radio-over-fiber ； multi-band optical carrier ； fiber optical cable television ； full-duplex

參考文獻

[1] D. R. Goff, Fiber optic video transmission, Burlington: Focal Press, 2003, pp53-72.

[3] S. J. Park, C. H. Lee, K. T. Jeong, H. J. Park, J. G. Ahn, and K. H. Song”, Fiber-to-the-Home Services Based on Wavelength-Division-Multiplexing Passive Optical Network”, IEEE Journal of Lightwave Technology, 2004, vol. 22, no. 11, pp.2582-2591.

[4] H. Takai, O. Yamauchi, “Optical fiber cable and wiring techniques for fiber to the home”, Optical Fiber Technology, vol. 15, no.4, 2009, pp.380-387.

[5] 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.

[6] 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.

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全雙工的光纖有線電視與微波傳輸系統

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