OCDMA-based 60-GHz radio-over-fiber system for next generation wireless access networks

Abstract

A high secure bidirectional 60-GHz radio-over-fiber (RoF) system is proposed and successfully demonstrated, based on optical code-division multiple access (OCDMA) encoding and decoding techniques. The optical carriers for both downlink and uplink transmissions are simultaneously generated in a lightwave centralized central station (CS), using the optical double sideband (ODSB) modulation of a dual-arm Mach-Zehnder modulator (MZM), so it can make remote base stations (BS) sourceless and colorless. Two-fiber topology is adopted in the scheme and therefore the effect of Rayleigh backscattering (RB) is neglected. We employ super-structured fiber Bragg gratings (SSFBG) as the OCDMA encoders and decoders, in order to obtain a preferable performance of our proposed OCDMA-RoF system.