Full-duplex hybrid PON/RoF link with 10-Gbit/s 4-QAM signal for alternative wired and 40-GHz band wireless access based on optical frequency multiplication

A novel full-duplex hybrid passive optical network/radio over fiber (PON/RoF) link with 10-Gbit/s 4-ary quadrature amplitude modulation (4-QAM) signal for alternative wired and wireless converged access is proposed. In the central station (CS), optical frequency multiplication (OFM) is implemented to generate millimeter-wave (mm-wave) band optical carrier with three tones via a dual-electrode Mach-Zehnder modulator (DE-MZM). The downlink QAM baseband signal is modulated on one sideband via an optical I/Q modulator. At the hybrid optical network unit (HONU), the downlink converged signal is routed into different receiver modules to achieve wired or wireless access. Moreover, the centralized lightwave separated from the downlink is reused as the uplink optical carrier for either wired or wireless access, and modulated by the baseband or mm-wave data of the uplink alternatively. Since the HONU is free from the laser source, the system complexity and cost are reduced. The simulation results show that our proposed full-duplex hybrid PON/RoF link for the alternative wired and wireless access maintains good performance even when the transmission link with standard single mode fiber (SSMF) is extended to 30 km. (C) 2017 Elsevier GmbH. All rights reserved.