A full-duplex radio-over-fiber transport system based on a direct-detection scheme is proposed and demonstrated. In this approach, the rf power degradation induced by fiber dispersion can be avoided for downlink transmission within the base station zone and for uplink transmission, even as the optical carrier and two sidebands are transmitted. A data signal of 70 Mbps/10 GHz transmitted over an 80 km single-mode fiber transport for both downlink and uplink with a low bit error rate (<10(-9)) and high spurious-free dynamic range (>100 dB/Hz(2/3)) values were achieved.