Impact of Reflections on Uplink Transmission in Optical Full Duplex Analog Radio Networks Using Centralized Sources

In this paper, the impact of reflections in full duplex optical networks transmitting analog radio signal is investigated. The experimental testbed has been proposed according to the verified pilot optical full duplex system based on a centralized optical source, which is used to transmit a 5G new radio signal at the frequency band of 40 GHz. To reveal the impact of reflections in the proposed testbed, a different level of reflected signal at the same wavelength is emulated for the range of relative reflected power (RRP) from 7 dB to 43 dB in intensity and phase modulation schemes. Signal reflections significantly degrade the uplink performance for RRPs below 30 dB for intensity modulation, whereas the phase modulation approach leads to a performance drop for RRP values below 40 dB.