The Receiver Circuit of Visible Light Communication

LEDs are semiconductor devices that emit light when biased in the forward direction of the p-n junction. LEDs present many advantages over traditional light sources, including lower energy consumption, longer lifetime, improved robustness and smaller size. A significant attribute of LEDs is their ability to switch on and off thousands of times per second. No other lighting technology has this capability. This switching occurs at ultra-high speeds, so far beyond what the human eye can detect, that the light appears to be constantly on. These embedded signals are emitted from the LEDs in the form of binary code; 'off' equals zero and ' on'equals one. This is what they call visible light communication (VLC). When VLC equipment and devices are placed throughout a building of geographical area, a comprehensive wireless communication network can be created. This thesis talks about a stand alone receiver. The receiver will be a device to plug in a digital port of the computer. It receives information from the emitted light and send it to the PC. The transmitted information will give the receiver the possibility to determine his current position in a room by looking at the amplitude of the signals he receives from multiple LEDs. It can also be used to transmit other digital information/files.