Abstract: Traditional radio over fiber (RoF) systems are susceptible to nonlinear during optical transmission, while digital radio over fiber (DRoF) systems can achieve higher signal fidelity through RF signal digitization. In this paper, an field programmable gate array (FPGA) system design for discrete cosine transform (DCT) real-time signal compression DRoF is proposed. Experimental results demonstrate that after DCT signal compression and signal quantization, the error vector magnitude (EVM) performance of 4-QAM, 16-QAM, and 64-QAM orthogonal frequency division multiplexing (OFDM) signals is better than that of the traditional k-means vector quantization scheme. The EVM performance is better than that of the traditional k-means vector quantization scheme, and the corresponding EVM performance of the three different modulation formats is stabilized at 12.8%, 5.7%, and 3.8%, respectively, and all of them are lower than the 3GPP threshold, which proves the feasibility of this scheme.