Enhancing optical CDMA

The use of spread spectrum technology continues to be of interest in optical communication networks. Fiber-optic systems offer access to large bandwidth and ultra-high signal processing speeds are possible in the optical medium. Optical code-division multiple-access (O-CDMA) is therefore evolving into a promising candidate for next-generation broadband communications, due to its potential for enhanced information security, simplified network control and management, as well as the fair division of bandwidth. This paper presents a brief review of the O-CDMA technique followed by discussion of recent developments at Warwick. In particular, the development of a new set of padded orthogonal codes to reduce multiple-access interference (MAI), the employment of M-ary pulse-position modulation (PPM) to improve system capacity and fuzzy logic based power control.