Performance of Dispersion Effects in OCDMA Systems and Timing Jitter with Fiber Type

Abstract

The aim of the thesis is to study dispersion effects in OCDMA systems and to study the timing jitter with type of fiber. The first objective of the thesis is to analysis the effect of dispersion of fiber on the performance of OCDMA system and to find the limitations imposed by dispersion on number of user and length of transmission. It has been observed that in the bit error rate performance curve the error is decreased when the number of subscriber is increased side by side the optical power is reduced when the users is added. Here for the user sequence is the m sequence. An OCDMA system is simulated with no dispersion, dispersion and dispersion compensation in order to analyze the effects of dispersion. Various graphs have been taken to evaluate the impact of fiber chromatic dispersion on the bit-error-rate (BER) and the Q factor. Eye diagrams have been taken at different stages in OCDMA system in order to study the effect of dispersion. Received signal is also measured in all the cases. The second objective of the thesis is to study different types of fibers with timing jitter. The simulation effort for 10 Gb/s optical communication system is done to select the fiber from the standard fibers available from some reputed fiber sources. The comparison on the basis of measured bit error rate (BER), Q-value, timing jitter and eye diagrams has been taken and presented. It was found that dispersion shifted normal & anomalous fibers give best performance among the fibers considered, second best performance is given by Corning LEAF fibers.