Bidirectional RoF 5G Fronthaul Transmission Links with an InAs/InP Quantum Dash Laser

We have experimentally demonstrated a bidirectional radio-over-fiber (RoF) 5G new radio (NR) fronthaul transmission link based on an InAs/InP quantum dash mode-locked laser (QD-MLL), which provide low noise and highly coherent optical carriers. Two of the optical carriers are used for heterodyne based millimeter wave (MMW) RoF downlink transmission. The signal of the downlink is a 2-GBaud 16-QAM signal located at 28.951 GHz after heterodyne detection. The third optical carrier is used in uplink. The signal used in the uplink is a 2-GBaud 16-QAM signal located at 4 GHz. The result is verified by error-vector-magnitude (EVM) in real-time. The EVM of the downlink and uplink is up to 9.5% and 7.9% respectively in back-to-back setup.