Absolute Value Layered ACO-OFDM for Intensity-Modulated Optical Wireless Channels

Both enhanced unipolar orthogonal frequency division multiplexing (eU-OFDM) and layered asymmetrically clipped optical OFDM (LACO-OFDM) are among the most spectrally efficient modulation techniques for intensity modulated links that layer multiple non-negative signals. In this paper, we propose absolute value layered asymmetrically clipped optical OFDM (ALACO-OFDM) which further improves the spectral efficiency while using a smaller number of …