LED Wireless: A Novel Use of LEDs to Transmit Audio and Digital Signals

THE SUPERIORITY OF LIGHT-EMIT-ting diodes (LEDs) over incandescent lights, due to long life expectancy, high tolerance to humidity, low power consumption, and minimal heat generation, is well supported. LEDs are used in message display boards, signal devices, and many other means of illumination. One important characteristic of LEDs is that they are semiconductor devices capable of fast switching with the addition of appropriate electronics. That is, the visible light emitted by LEDs can be modulated and encoded with audio information for broadcasting. Therefore, in addition to their normal functions as indication and illumination devices, LEDs can be used as communication devices for transmitting and broadcasting audio and digital information. Hence, they can become part of wireless optical-communication systems. This article describes an information system for the broadcasting of audio and digital signals using visible LEDs.