Patent ID: 8666259
Filing Date: 2014-03-04
Classification: H04B

Abstract:
1. A method for transmitting data by a visible light communication (VLC) apparatus, the method comprising: setting up a pulse width control step of pulse width modulation (PWM) within a unit time interval; if the pulse width control step is 2 converting the m bit symbols into 2m bit symbols; modulating the 2m-bit symbols into PWM signals, with the PWM signals being generated by combining a PWM signal corresponding to m bits of the 2m-bit symbols within a unit time interval and a PWM signal corresponding to a rest of bits of the 2m-bit symbols within a unit time interval; generating a visible light modulation signal by controlling the turn-on time or turn-off time of a plurality of light emitting diodes (LEDs) in response to the PWM signals; and transmitting the visible light modulation signal, wherein m is an integer of 2 or more.