An Adaptive Iterative Symbol Clipping Scheme for OFDM-Based Visible Light Communication

In this paper, an adaptive iterative symbol clipping scheme for OFDM-based visible light communication systems is proposed. This scheme can avoid the disadvantages of the conventional iterative signal clipping (ISC) scheme that produces all-zero symbols due to the fixed iterative clipping times, and also avoids the information transmission rate degradation due to an adaptive symbol decomposition with serial transmission (ASDST) scheme using serial transmission. In the proposal, optical orthogonal frequency division multiplexing (O-OFDM) symbols are decomposed into multiple O-OFDM symbols that are in the linear range of the LEDs after adaptive iterative clipping according to the signal amplitude and clipping threshold, thereafter simultaneously transmitted through multiple LEDs. When the number of LEDs is large enough, clipping distortion can be significantly reduced or even completely eliminated. In addition, the all-zero symbols existing in the ISC scheme can be completely eliminated. Experimental results show that the proposed scheme can not only improve the BER performance and the optical power efficiency, but also reduce the clipping times compared with the traditional ISC scheme. Besides,our proposed scheme could achieve higher information transmission rate compared with the ASDST scheme.