Focused on two functions of illumination and high rate transmission provided by indoor visible light communication systems,the performance of dimming control with pulse width modulation and bit error rate for Orthogonal Frequency Division Multiplexing based visible light communication was analyzed. A new dimming control scheme based on unipolar orthogonal frequency division multiplexing was proposed due to better performance in terms of both power efficiency and bit error rate achieved by unipolar orthogonal frequency division multiplexing. The dynamic-range of drive current and bit error rate performance were simulated,and the results show that unipolar orthogonal frequency division multiplexing system can obtain better error performance in the mean time without sacrificing illumination quality. In addition,a novel system scheme named zero-padding asymmetrically clipped optical orthogonal frequency division multiplexing is presented,which is more efficient in power for the demand of weak lighting intensity and low power consumption. Simulation results show that zero-padding asymmetrically clipped optical orthogonal frequency division multiplexing system can improve the power efficiency of the system without loss of error performance.