Indoor Visible Light Wireless Communication System

Recently, the Indoor visible light wireless communications technology is emerged companied with the blooming white light-emitting diode (LED) lighting technology. Thanks to the white LED's excellent properties such as low power consumption, long lifetime, high reliability and short response time, it is possible to upgrade the indoor white LED illumination source to a wireless optical communication systemIn this thesis, we analysised the current visible light communication system and discussed the key technology of indoor visible light wireless communications technology.Firstly, we build a model to calculate the luminosity distribution of the white LED light source, and then find out the best lighting layout of white LEDs through numerical simulation.Secondly, after the research of visible light communication code, we designed a pulse position modulation scheme which could solve the difficulty of clock synchronization in conversional modulation format.Thirdly, we designed a visible light communications system and realized the data transmission between the transmitter and the receiver based on the proposed system.Finally, we designed a self-adaptive voltage discrimination to resolve this problem and demonstrated is by numerical simulation, since people's shadow will influence this system largely; we proposed a multi-step coding method, which could greatly enlarge the communication bit rate. We proposed an indoor wireless communication system for the multi-terminals and give a compatible communication protocol.We studied the wireless visible light communications systems, constructed the system, solved the influence of shadow and improved the communication rate of system in this paper. We do lots of foundation works for further development of systems.