Institute of Electrical & Electronic Engineers
In this paper, the performance of indoor OFDM (Orthogonal Frequency Division Multiplexing) Optical Wireless (OW) communication systems in the presence of LED (Light Emitting Diode) clipping distortions is analyzed. Two indoor OW OFDM techniques are considered. An ACO-OFDM (Asymmetrically Clipped Optical OFDM) system produces half-wave symmetry time signal at the output of the OFDM modulator by special assignment of subcarriers. Therefore, bipolar-unipolar conversion is achieved by clipping the signal at the zero level at the expense of data rate reduction. The second technique, called DCO-OFDM (DC-biased Optical OFDM), assigns data to all possible subcarriers to increase the data rate.