Title :
Asymmetrical Hybrid Optical OFDM for Visible Light Communications With Dimming Control
Author :
Qi Wang ; Zhaocheng Wang ; Linglong Dai
Author_Institution :
Dept. of Electron. Eng., Tsinghua Univ., Beijing, China
Abstract :
This letter proposes an asymmetrical hybrid optical orthogonal frequency division multiplexing (AHO-OFDM) scheme for dimmable visible light communication systems. In the proposed scheme, either asymmetrically clipped optical OFDM (ACO-OFDM) or pulse-amplitude-modulated discrete multitone (PAM-DMT) signal is inverted and then both the signals are combined for transmission, where pulsewidth modulation is no longer required for dimming control. The power of ACO-OFDM and PAM-DMT signals is adjusted so that the amplitude of the combined AHO-OFDM signal is asymmetrical, which could utilize all the available subcarriers as well as the entire dynamic range of light-emitting diodes with various dimming levels. Simulation results show that the proposed scheme could achieve a wide dimming range with a small throughput fluctuation.
Keywords :
OFDM modulation; light emitting diodes; optical communication; optical modulation; pulse amplitude modulation; ACO-OFDM; AHO orthogonal frequency division multiplexing scheme; Dimming Control; PAM-DMT signal; asymmetrical hybrid optical OFDM scheme; asymmetrically clipped optical OFDM; dimmable visible light communication system; light emitting diode; pulse,amplitude modulated discrete multitone signal; Dynamic range; OFDM; Optical modulation; Optical pulses; Optical receivers; Pulse width modulation; Time-domain analysis; Orthogonal frequency division multiplexing (OFDM); dimming control; light emitting diode (LED); visible light communication (VLC);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2015.2404972
