Design of indoor wireless communication system using LEDs

An indoor wireless communication system using off-the-shelf white LED was presented in this paper. We adopted OOK (On-Off Keying) modulation in transmitter module. Data transmission was realized based on RS-485 protocol. A DC-balanced coding with error check and correction abilities was applied to avoid blinking and improve the performance of the system. The system can keep 10-7 error bit rate within 2.5m reach at a rate up to 115200 bps.