Zhang, Shu Fen creator Zhang, Jian-Guo Chairperson Ahmed, Kazi Mohiuddin Examination Committee Makelainen, Kimmo Examination Committee Asian Development Bank, Japan Scholarship donor text th Bangkok Asian Institute of Technology 1996 monographic eng

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76 p. Optical transm1ss1on has become more and more widely used recently. The new modulation techniques associated with the transmission system need to be investigated for a better system performance in a cost effective manner. In this thesis study is to investigate the application of the digital pulse width modulation technique DPWM in optical fiber transmission system. A way of signal detection named timing window detection method is presented. The standard of time decision error is also established. The relationship between error probability and receiver sensitivity of the three systems are derived based on the error occurrence mechanism. The system performance of 2, 4, and 8-level PWM system is evaluated in the presence of the noises. The receiver sensitivity performance is analyzed by considering the bit error rate of 10·9 for the optical receiver using Avalanche Photodiode detector. The minimum required average peak optical power, which is required by digital optical fiber system to guarantee the 10·9 BER at an optical receiver, is calculated. The analysis results show that the 4-level PWM system can perform better than other PWM systems. The effect of the timing detection window width to the receiver sensitivity is also investigated. The receiver sensitivity performance of DPWM system is compared with the convensional PCM system for the same system parameter used. Results show that the 2-level, 4-level and 8-level PWM can perform better than PCM system at lower bit rate A thesis report submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology Thesis (M.Eng.) - Asian Institute of Technology, 1996 Optical communications Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B14969 http://203.159.5.9/ait-thesis/detail.php?q=B14969 180698 20260817161122.0