Simultaneous Wired and Wireless 1.25-Gb/s Bidirectional WDM-RoF Transmission Using Multiple Optical Carrier Suppression in FP LD

In this paper, a new bidirectional wavelength division multiplexing radio-over-fiber (WDM-RoF) scheme is proposed with multiple optical carrier suppression for simultaneous wired and wireless 1.25-Gb/s signal transmission. For downstream signals, all modes of a Fabry-Perot laser diode are simultaneously suppressed by a Mach-Zehnder modulator at V _pi bias point to mitigate a chromatic dispersion. A reflective SOA is used both for reduction of mode partition noise induced from the Fabry-Perot laser diode and for the downstream modulation of each channel. The effect of mode partition noise (MPN) reduction is verified by measuring radio frequency (RF) spectra and phase noises. For an upstream signal, another reflective semiconductor optical amplifier (RSOA) in base station (BS) is used by remodulation technique, which is verified by measuring both the RF spectra and a dynamic rage of an optical input power to the RSOA. A bit error rate (BER) of 10^-11 for three downlink channels and one uplink channel at 1.25 Gb/s are experimentally demonstrated after 23-km SMF transmission.