Transmission of multibands wired and wireless orthogonal frequency division multiplexing signals using a full-duplex dense wavelength division multiplexing radio-over-fiber system

We propose and demonstrate a full-duplex dense wavelength division multiplexing (DWDM) radio over fiber (ROF) system transmitting multibands wired and wireless orthogonal frequency division multiplexing (OFDM) signals. In a central station, an optical signal noise ratio (OSNR)-boosted multicarriers generator based on recirculation frequency shifter (RFS) is used to generate multicarriers. Sixty-six frequency-lock and coherent, 25 GHz frequency-spacing subcarriers with OSNR larger than 26 dB with an amplitude difference of 5 dB are generated and used to transmit downstream data. Since these subcarriers are coherent with each other, n-fold frequency optical millimeter-wave signals can be generated. Without using costly W-band components, a 20 Gbps downstream transmission operation at 75 GHz is experimentally validated. The power penalty of less than 3 dB was observed after a 50-km single mode fiber (SMF) and 4-m wireless transmission. In order to realize the full duplex system, a 1.2 GHz bandwidth reflective semiconductor optical amplifier (RSOA) is used to achieve 5 Gbps upstream traffic for 16QAM-OFDM signals. The measured power penalty of 3 dB is observed after a 50-km SMF transmission at the bit error rate of 3.8×10 −3 .