Proposal of new optical CDMA systems and fast code acquisition techniques

Optical CDMA provides several attractive features: a simple access protocol, desirable quality deterioration, flexibility of user allotment, flexibility of asynchronous, decentralized network operation, and inherent data security. The paper presents a new optical CDMA system for office LAN systems and demonstrates the validity of our system by using a 10-Gbps optical fiber system. Moreover, a new technique for fast code acquisition is presented and demonstrated. The technique using DFF as a digital code-pattern comparator has the significant merits of faster code acquisition and lower power consumption than the conventional serial-search code-acquisition technique and the parallel-search code-acquisition technique using a matched filter.