![]() | Only 14 pages are availabe for public view |
Abstract The cptical orthogonal code division multiple access (OOCDMA) has been widely used in both one dimensional (lD) and two dimensional (2D) wavelengths hopping/time spreading (CDMA) systems. This thesis give an overview on time division multiple access (TDMA) , frequency division multiple access (FDMA) , and code division multiple access (CDMA). It discusses optical CDMA techniques, optical CDMA devices, and types of OCDMA. The types of optical CDMA receivers have been studied. Also, we demonstrate optical orthogcnal codes, mark position differences, and noises in optical systems, especially shot and thermal noises. Proposing a new code called OC2DMA and a new implementation for dynamic OC2DMA transmitter and receiver. The probability of error for a dynamic noiseless optical system with different codes (ID OCDMA, 2D OCDMA, and OC2DMA), using 15 active users, 31 wavelengths and code lengths between (9 to 25) and (25 to 49) chips, have been analyzed. The effect of shot noise and of shot and thermal noises together, on the performance of 1 D OCDMA, 2D OCDMA, and OC2DMA wavelength hopping/time spreading dynamic noisy systems is analyzed. Also the probability of error is calculated for general systems employing asymmetric prime-hop codes (APHCs). A comparison is held between the performance of dynamic [ID OCDMA (0.90 x 10-2), 2D OCDMA (0. 97 x 10-2), and OC2DMA (0.20x 10-5)] correlation receivers under the effect of both shot and thermal noises. The analysis reveals that the performance of the dynamic noisy OC2DMA correlation receiver is better than both dynamic noisy ID CDMA correlation receiver and dynamic noisy 2D OCDMA correlation receiver. |