Heterogeneous RoF, RoFSO and RF bidirectional links in n79 5G band

In this paper, we demonstrate the experimental transmission of radio signal in the n79 new radio (NR) 5G frequency band over a fronthaul optical infrastructure consisting of a 10 km standard single-mode fiber, 100 m long free-space optics channel and a seamless 2 m long radio frequency link for downlink and uplink characterization. The predefined signal using 64-quadrature amplitude modulation and 20 MHz bandwidth has been used for testing while the error vector magnitude (EVM) parameter was measured. The results are also presented in terms of received optical and electrical power as well as the signal-to-noise ratio. The successful transmission over the whole proposed network with the EVM below the required limit of 9% is demonstrated for the received optical power of 0 dBm and 2.3 dBm for the downlink and uplink, respectively.