Real-time digitized RoF transceiver technology based on FPGA

Radio over fiber (RoF) has become a promising alternative for 5G mobile fronthaul due to its inherent advantages of large bandwidth, low susceptibility to radio frequency interference, and high flexibility. In traditional RoF system, analog signals are transmitted through optical fiber, which is susceptible to nonlinearity and dispersion. However, digitized radio over fiber (DRoF) can effectively mitigate these defects by digitizing the analog signals. This paper explores FPGA-based real-time DRoF transceiver technology, which utilizes varying numbers of quantization bits for real-time vector quantization across different modulation formats. This approach helps prevent the reduction of system spectral efficiency caused by excessive quantization bits. The simulation results demonstrate that, after real-time vector quantization and transmission with 8 and 10 quantization bits, the EVM performance of QPSK and 16-QAM signals stabilizes at 11.8% and 6.7%, respectively, thereby confirming the effectiveness of the proposed scheme.