Real-Time Transmission of ROF-FSO Hybrid System Using Software Defined Radio

This paper presents an experimental real-time transmission system of radio over fiber (RoF) and free space optics (FSO) based on software defined radio (SDR). Moreover, a free space link with a length of 3 meters and a radio frequency (RF) link with a length of 1 meter are used to simulate the long-distance communication between the base-band unit (BBU) and the remote radio unit (RRU) in order to promote the development of full coverage of wireless networks. On the basis of USRP B210, SDR generates DQPSK RF signal, 8PSK RF signal and 16QAM RF signal which are integrated with radio-over-FSO (RoFSO) platform to demonstrate end-to-end transmission. Using the advantages of software radio, the feasibility of our proposed system architecture is successfully demonstrated. At the same time, we analyze the performance of signals at different frequencies in the GNU Radio software.