PWM-based PPM format for dimming control in visible light communication system

We report simulation results of pulse width modulation (PWM)-based pulse position modulation (PPM) signal format for visible light communication systems. For simultaneous operation of data transmission and dimming control, PPM data format is added to PWM dimming control signal. To show dimming control, the PWM duty ratio is changed from 40 % to 80 % during PPM data transmission. The PWM frame rate is set to 1 kHz to avoid flickering in human eyes. The PPM data rate is set to 20 kb/s. The waveforms, eye diagrams and BER of this system are calculated. The simulation shows the BER of 1×10
⁻⁵
is achievable.