Home intercommunication system using visible light communications

The fast growing technology of wireless data transmission through the illumination of light emitting diodes (LEDs) is known as visible light communications (VLC). This technology makes use of visible light as the carrier for transmitting signals over a wireless channel. VLC uses the visible light spectrum for transmission and one of the main advantages of VLC over radio frequency (RF) based communications is that VLC is not susceptible to electromagnetic interference. In this project, VLC is used for the transmission of audio over an optical wireless channel. This is achieved by designing and implementing a simplex intercom system that comprises of a transmitter, a channel and a receiver and the system transmits audio through visible light using on-off keying (OOK) modulation. In this modulation scheme, the intensity of light is varied by switching the LED on and off at a high frequency such that the switching is not detectable by the human eye. The results of the project demonstrate that audio transmission is achievable with visible light.