We demonstrate a visible light communication system based on DC-biased optical orthogonal frequency-division multiplexing (DCO-OFDM) and achieve a bit rate of 481 Mb/s at a communication distance of 65 cm by employing single 1-W commercial phosphorescent light-emitting diode (LED). The average bit error rate of the received data is 2.3×10-3, which is below the forward error correction limit, 3.8×10-3. The effect of -signal clipping in DCO-OFDM system is studied and resource allocation algorithms are utilized. At least 13% capacity improvement can be obtained by suitable signal clipping and resource allocation.