The Layout of VLC Light Source for Both Lighting and Communication Reliability

In the visible light communication (VLC) system, the light emitting diode (LED) has a double function of illumination and communication. In order to take the illumination uniformity and the communication reliability into consideration, taking a 4m * 4m * 3m room as the model, four LED arrays are used as the indoor light source. First of all, through the formula calculation combining with the software simulation analysis obtained that the size of the 9x9 LED array can meet the indoor illumination needs; Secondly, analysis respectively from the distribution of illumination uniformity and reliability of the communication perspective, different layouts are obtained. Finally, in order to take the uniformity of the illumination distribution of VLC system and the reliability of communication into consideration, the system optimization model function f(L,i) is constructed by the standard deviation of the illumination of the indoor receiving plane and the average error rate of the receiving plane in the communication. When the minimum value of f(L,i) is reached, the receiving plane illumination uniformity requirements and communication bit error rate requirements can be guaranteed at the same time. At last, through the simulation the minimum value is obtained when L = 0.55 m and i = 0.01 m. The minimum value of the illumination of the receiving plane is 337.52lx, the maximum is 482.05lx, the uniformity is 76.97%, and the error rate is 2.81*10^-7. The results show that the system can take into account the uniformity of indoor light distribution and the reliability of communication.