Novel WDM-based Quasi-synchronous Coherent Time-spreading Optical CDMA System

摘要

Based on wavelength-division multiplexing (WDM) and optical code-division multiple access (OCDMA), we propose a novel WDM-based quasi-synchronous coherent time-spreading OCDMA system (WDM + QOCD-MA). In WDM + QOCDMA network, the synchronization among users using the same wavelength channel can be controlled within several chip-lengths, and beat noise (BN) and multiple access interference (MAI) can be eliminated. Simulation of four simultaneous users employing LA sequence (156, 8,16) is demonstrated, where the fiber link consists of 10 km single-mode fiber, plus 1 km Dispersion Compensating Fiber. WDM + QOCDMA system can support sufficient number of active users for error-free transmission. Another advantage is that the near-far problem of WDM + OCDMA system can be eliminated, and complicated power control can be removed. Therefore, this scheme is a good candidate for optical access network.