双灯可见光定位的时频结合实现方案

Time-Frequency Combination Based Two-LED Positioning in Visible Light Communication

传统的可见光定位方案通常需要至少3个光源,提出一种融合镜面反射的系统模型,并采用时频结合法实现两灯定位。该方案基于时频结合法和接收信号强度算法,将一个虚灯的镜面反射功率融入其对应的实灯的有效定位功率中,将另一个虚灯独立出来作为用来定位的第3个光源。为了在接收端分离出每一路用于定位的信号,接收端通过滤波器检测频域信号,通过时分采样检测来自时域的脉冲信号,并通过脉冲信号的到达时间将实灯与其对应的虚灯分开,从而实现两灯定位。仿真结果表明,基于虚灯的两灯定位方案对于靠近镜面的半间房间可以进行有效定位,定位精度随着接收机和镜面之间距离的减少而呈现上升的趋势,通过进一步改变两灯距离镜面的位置,可以将平均定位误差减小至12.4 cm以内。

The traditional visible light positioning scheme usually requires at least three light sources.In this study,a system model that integrates mirror reflection is proposed,and a time-frequency combination method is utilized to achieve two-LED positioning.The proposed scheme is based on the time-frequency combination method and received signal strength algorithm.It integrates the specular reflection power of one virtual lamp into the effective positioning power of its corresponding real lamp and separates the other virtual lamp as the third light source for positioning.To separate each signal used for positioning at the receiving end,the receiving end detects the frequency domain signal through a filter,detects the pulse signal from the time domain through time division sampling,and separates the real light from its corresponding virtual light through the arrival time of the pulse signal,thereby achieving the two-LED positioning.The simulation results show that the two-LED positioning schemes based on virtual lights can effectively locate a half-room near the mirror surface.Furthermore,the positioning accuracy shows an upward trend as the distance between the receiver and mirror surface decreases.Additionally,the average positioning error can be reduced to within 12.4 cm by further changing the position of the two lights from the mirror surface.