Multiplexing scheme for digital signal processing-assisted coherent radio over fiber system

Abstract

In this paper, a multiplexing scheme, involving optical tandem single-sideband modulation, orthogonal optical single-sideband multiplexing, and digital signal processing (DSP)-assisted optical coherent detection, is proposed. Based on the design, a coherent radio-over-fiber (RoF) optical transmission system is established, which improves channel capacity and spectrum efficiency. Phase-modulated radio frequency signals with different bit rates are carried on an optical single-carrier, transmitted, received after 40 km transmission, and recovered by the DSP algorithm. System performances for all binary phase-shift keying channels are verified by simulation and experiment. Thus, the proposed multiplexing scheme is feasible to improve channel capacity and spectrum efficiency without increasing the system complexity. The work in this paper brings potential applications to coherent RoF systems and hybrid optical wireless communications for future broadband wireless access networks.