A survey and a novel scheme for RoF-PON as FTTx wireless services

In this paper, desirable features of network architectures and enabling novel technologies for delivering future millimeter-waveband (mm-WB) radio-over-fiber (RoF) system for wireless services with the use of dense wavelength division multiplexing (DWDM) architecture is proposed. For the conceptual illustration, we considered a DWDM RoF system with channel spacing of 12.5 GHz. In the downstream system, the millimeter-wave-band RF signal is obtained at each Optical Network Units (ONUs) by using optical heterodyning photo detection between two optical carriers simultaneously; one optical carrier is modulated with the downloading customer data, while the second is un-modulated carrier. The generated RF modulated signal has a frequency of 12.5 GHz. In the upstream system, we used direct photo detection. Such a RoF system has simple, cost-effective, maintenance-reduction and is immune to laser phase noise in principle. We include in this paper a survey of related RoF network proposals and experiments as well as a background of these technologies.