Visible Light Communication Source Layout And Modulation Techniques

Visible light communication technology is a new wireless communication technology in recent years, using the speed bright and dark of white LED to transmit information, so that the LED have both lighting and communication purposes, the white light not only has very wide spectrum resources, but also the use of these resources does not require authorization. Thus, the discovery of this technology can solve the existing spectrum resource shortages of RF communication technology, and with the rapid spread of white LED as a light source, visible light communication technology makes the Internet more convenient. White light does not have conventional electromagnetic radiation of the RF communication, making communication more green. The fusion of visible light communication technology and power line technology, makes the wiring visible light communication more convenient compared to traditional communications base stations’ establish to be more convenient and easier to set up and dismantle. In summary, the study of visible light communication technology is of great significance.Therefore, this paper expand research for the above two problems. In order to study the layout of the LED light source, studied some of the LED light-emitting principle and main features first.Secondly, studied the visible light communication link method and communication channel model. About the layout of the light source,this paper proposesd a layout algorithm of visible light source which is universal, through simulation show that the algorithm can be applied to any rectangular room layout light source optimized if use the LED array as the light source, so as long as we know the length and breadth of the room, we can use the algorithm to solve the optimal LED array layoutAt last, studied several commonly used modulation methods of the visible light communication and their basic principles, advantages and disadvantages, etc. Focusing on the principles of OFDM modulation method, and the problem of peak-to-average, and rised an improved method to solve this problem. In addition, this paper compared the single carrier modulation and multi-carrier modulation performance of the visible light communication, the comparisons considered the impact of nonlinear LED on the system performance, the simulation results show that the visible light communication single carrier modulation has better performance than multi-carrier modulation.