Multichannel Digitized RF-Over-Fiber Transmission Based on Bandpass Sampling and FPGA

In this paper, we proposed multichannel digitized RF-over-fiber (DRoF) transmission scheme and realized frequency conversion using a single analog-to-digital converter (ADC) and a single digital-to-analog converter (DAC). We gave a comprehensively analysis on this scheme, and compared it with analog links in terms of signal-to-noise ratio (SNR), dynamic range and performance degradation with channel number increasing. We experimentally implemented a multichannel DRoF uplink using commercially-available field programmable gate array (FPGA) and ADC with satisfactory error-vector-magnitudes (EVM) of less than 1%. Results show that the interference level in DRoF link is dependent upon the channel spacing of the reconstructed signal. We theoretically and experimentally proved that the DRoF technique is sufficient to construct a high-performance cost-effective RF-over-fiber link, especially for long-haul fiber radio networks.