Study of Phase Compensation to Overcome Power Fading for Ultra Wideband-over-Fiber Systems

• Main Authors: Yi Shu Chen, 陳逸書
• Other Authors: W. P. Lin
• Format: Others
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/18756745581107117502

碩士 === 長庚大學 === 電機工程學系 === 99 === Due to the invention of Erbium-doped fiber amplifier, the fiber loss of wavelength 1550 nm is overcoming. Fiber communication for long distance and high transmission rate is achieved. Nevertheless fiber length, modulation frequency and dispersion coefficient made different phase shift caused power reduction. These factors restrict the quality of transmission system. Hence, the way to compensate for fiber dispersion becomes the main research topic in fiber communication systems. In this thesis, we introduce the theorem of optical double-sideband (ODSB) modulation and fiber chromatic dispersion incidental to ODSB modulation. Recently, several methods have been reported for generation optical single-sideband (OSSB) to figure the problem. However, when OSSB is used, power losses of 3 dB occur due to the suppression of one sideband compared with ODSB. In this paper, a concept of ODSB phase compensation is used to overcome dispersion induced power fading. The ODSB phase compensation is analyzed in simulation and experiment to compare with OSSB and general ODSB modulation. Furthermore, we verify this technique experimentally for multiband orthogonal frequency division multiplexing ultra wideband (MB-OFDM UWB) signals, and analyzing the effect on different fiber transmission distances, RF frequencies, transmission rates, wireless transmission distances and modulation index. To realize radio-over-fiber technique is based on MB-OFDM UWB transmission systems.