High-Accuracy Height-Independent 3D VLP Based on Received Signal Strength Ratio

Abstract

Visible light positioning (VLP) has attracted intensive attention from both academic and industrial communities thanks to its high accuracy, immunity to electromagnetic interference, and low deployment cost. In general, the receiver in a VLP system determines its own position by exploring the received signal strength (RSS) from the transmitter according to a pre-built RSS attenuation model. In such model-based methods, the LED’s emission power and the receiver’s height are usually required known and constant parameters to obtain reasonable positioning accuracy. However, the LED’s emission power is normally time-varying due to the fact that the LED’s optical output power is prone to changing with the LED’s temperature, and the receiver’s height is random in a realistic application scenario. To this end, we propose a height-independent three-dimensional (3D) VLP scheme based on the RSS ratio (RSSR), rather than only using RSS. Unlike existing RSS-based VLP methods, our method is able to independently find the horizontal coordinate, i.e., two-dimensional (2D) position, without a priori height information of the receiver, and also avoids the negative effect caused by fluctuation of the LED’s emission power. Moreover, we can further infer the height of the receiver to achieve three-dimensional (3D) positioning by iterating the 2D results back into positioning equations. To quickly verify the proposed scheme, we conduct theoretical analysis with mathematical proof and experimental results with real data, which confirm that the proposed scheme can achieve high position accuracy without known information of the receiver’s height and LED’s emission power. We also implement a VLP prototype with five LED transmitters, and experimental results show that the proposed scheme can achieve very low average errors of 2.73 cm in 2D and 7.20 cm in 3D.

Experimental Demonstration of a Visible Light Communications System Based on Binary Frequency-Shift Keying Modulation: A New Step toward Improved Noise Resilience

“…Therefore, although VLC is a relatively new technology, its performances have reached a relatively high maturity level. Thus, indoor VLC prototypes have reached data rates of few tens of gigabits per second [11], are able to provide centimeter-level positioning accuracy [14], and can manage multiple users simultaneously [15]. On the other hand, vehicular VLC prototypes have reached almost 200 m communication ranges [16,17], have significantly improved optical noise resilience [18][19][20], and have provided latencies lower than 100 ms [19,21], while demonstrating their ability to be used in real traffic safety applications [22][23][24].…”

Indoor Visible Light Positioning System Based on Point Classification Using Artificial Intelligence Algorithms

“…Photo-detectors are more widely used owing to their low cost and low-power consumption. The existing indoor visible light positioning methods include RSSI, AOA, TOA, TDOA [13][14][15], etc. However, the angle-based and time-based positioning methods require additional synchronization equipment.…”