Simple 60-GHz MB-OFDM Ultrawideband RoF System Based on Remote Heterodyning

A simple 60-GHz radio-over-fiber system employing a combination of uncorrelated optical heterodyning and envelope detection is proposed and experimentally demonstrated. At the central office, a multiband orthogonal frequency division multiplexing ultrawideband (MB-OFDM UWB) signal is used for the external modulation of a dual-arm Mach-Zehnder Modulator to generate an optical signal-sideband signal, which is then coupled with an unmodulated free-running continuous wave laser. Optical heterodyne mixing at the base station and envelope detection at the customer unit are utilized. The experimental results confirm that photonic millimeter-wave signal generation and detection can be achieved without the need for complex optical phase-locked loops and high-frequency microwave sources. As a proof of concept, successful transmission of a 3.84 Gb/s 16-QAM MB-OFDM UWB signal over 48-km standard single-mode fiber without chromatic dispersion compensation and a further 4-m wireless channel is experimentally demonstrated.