Investigation of a SMF-MMF Link for a Remote Heterodyne 60-GHz OFDM RoF Based Gigabit Wireless Access Topology

A simple single-mode fiber/multimode fiber (SMF-MMF) 60-GHz radio over fiber scheme using a conventional central launching technique at 1550 nm is proposed and experimentally evaluated. The system targets cost-efficient Gigabit wireless access using already installed indoor MMF fed by a passive optical network topology. A complete characterization of the composite SMF/MMF/SMF optical medium is presented, in terms of coupling loss, power stability, and chromatic and modal dispersion. A robust multiband orthogonal frequency-division multiplexing optical single-side-band technique, employing envelope detector scheme, is used as to address the performance limitations imposed by the simple SMF-MMF coupling scheme, chromatic dispersion degradation, and phase noise owing to ordinary long-wavelength lasers. A characterization of the system is performed and a 3.84-Gb/s transmission is demonstrated over a scheme including 17.5-km SMF and 250-m MMF.