# Design of OCC Indoor Positioning System Based on Flat Panel Light and Angle Sensor Assistance
## 2 System Design  
The imaging VLP technology based on the received signal from the image sensor is characterized by the use of the image sensor as the front end of the receiving end of the VLP system. The image sensor is integrated on the camera, and the VLC system uses the camera as the front-end of the receiver [11]. The transmitter side of the OCC system has two processes: first, the data information to be transmitted is coded and modulated for transmission to the driver circuit, and then the driver circuit amplifies the received signal to drive the LED lamp to send the light signal. The modulation of the LED lamp is generally based on changing the luminous intensity of the light source, and Figure 1 shows a common i-VLP system. In this paper, an LED flat panel lamp is used as the emitter. A frosted barcode or 2D code with location information is either laser-engraved on the frosted acrylic or transparent \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Technique** & **Accuracy** & **Cost** & **Coverage** & **Stability** \\ \hline Infrared & High & High & Small & Low \\ Ultrasonic & High & High & Limited & Low \\ Wi-Fi & Relatively low & Low & Relatively large & Normal \\ ZigBee & Depends on anchor density & Low & Limited & High \\ Bluetooth & Low & Low & Relatively large & Low \\ UMB & High & High & Relatively large & Relatively high \\ VLP & High & Low & Relatively large & High \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparative analysis of classical indoor positioning techniques. Figure 1: A common i-VLP system. lampshade of the flat panel lamp, or the translucent frosted film paper is cut into the shape of the barcode or 2D code and pasted on the lampshade of the flat panel lamp to make it constitute a frosted graphic code. Without changing the circuit, the modification of the emitter can be realized, and the laying cost and modification cost are extremely low, simple to operate and practical. The signal transmitter side of the LED flat panel lamp information positioning technology proposed in this paper is easier to implement than the traditional OCC system, and as flat panel lamps become increasingly more used, the modification of only the lamp shade makes the hardware cost and system deployment cost much lower. The method is also more aesthetically pleasing compared to directly pasting the graphic code on the building. Figure 2 shows the ideal graphic code and a diagram of the two states of the flat panel lamp after the lamp has been retrofitted with the lamp off and the lamp on. LED flat panel light is a flat surface light source, and compared with traditional lamps and lanterns, the light source wattage is the same. LED flat panel light has the advantages of a soft light, a uniform, large luminous area, a high color rendering index, green energy saving, etc., which are becoming characteristics of choice for indoor lighting. At the receiving end, the user can shoot the frosted graphic code on the flat lamp shade through the camera of the mobile terminal (smart phone), the image undergoes digital image processing algorithms and machine vision methods, obtaining the LED-ID number of the flat lamp to achieve fuzzy positioning. Then, assisted by the angle sensor in the phone to extract the angle information, the calculation obtains the precise coordinates. Followed by this, through the indoor electronic map of the building, the own location information of the area completes the positioning. The whole system process is shown in Figure 3. This design is referred to as the LP-VLP system. The flat panel light positioning technology in this paper uses barcodes to represent location information. According to the design and practical needs of the positioning system in this paper, the barcode frosted film has the following two requirements. Figure 3: The LP-VLP system. Figure 2: Retrofitted flat panel light: (**a**) ideal model; (**b**) lights off; (**c**) lights on. (1) It must minimize the normal lighting function of the lamp.