Research On Key Technologies Of Indoor Visible Light Communication Based On LED

With the rapid development of modern science and technology,white LED has entered a stage of all-round development. White LED has the advantages of high brightness, low power consumption and long life,has a very important role and significance in the current wireless communication system, but by the white LED spectrum is equal to the effect of short, so its application is limited. With the rapid development of the concept of green communication, the research on the indoor visible light communication system for white LED is gradually deepening. Based on this background, in this research, the main research and analysis is the key technology of indoor visible light communication based on LED.The traditional indoor visible light MIMO-OFDM system has three research difficulties and is difficult to break through. First, unlike the wireless channel, optical channel model involves multiple reflection and absorption of more complex physical processes, there is no generally accepted the authority of the statistical model can be used to characterize the stochastic process; second, MIMO antenna array distribution and start to take into account the indoor lighting demand; third, optical signal spread easily by this the characteristics of physical barriers blocking is a double-edged sword. Therefore, according to the three study difficulties,this paper gives three corresponding solutions, so that the indoor visible light MIMO-OFDM system to obtain higher efficiency in the application of lower cost analysis, and can use traditional statistical tools. Firs, this paper introduces a hybrid optical channel model, the direct optical signal as a fixed amount is only related to the physical location of the receiving array, and the synthesis of multiple reflection optical signal as a random variable to handle. Second, we use a variable frequency band to characterize the switching state of a light emitting array, rather than the varying transmit power. Third, in view of the visible light communication cannot penetrate physical barriers and lead to high equipment cost, we propose optical relay network model, which will cross the physical barriers scene into a two jump (two-hop) communication scene, so as to achieve the purpose of decoding turn light signal, and then to realize optical signal transmission across the physical barriers.