Visible light positioning system and method based on timing sequence markers

Abstract

The invention provides a visible light positioning system and method based on timing sequence markers and relates to the field of LED optical communication and indoor positioning application. A sending terminal sends pseudorandom sequences having the same content through a plurality of LEDs according to different delays; a light detector of a receiving terminal detects multiple beams of signal light simultaneously, the signal light is converted into an electrical signal, self-correlation operation is conducted on the electrical signal and the pseudorandom sequences of the sending terminal, and timing sequences and correlated peak values corresponding to the signal light from the different LEDs are determined; the correlated peak values of signals from any three different LEDs and the coordinates of the corresponding LEDs are substituted into the equation that I(theta)=F(theta)*I0, simultaneous calculation is conducted, and the coordinates (x, y, z) of the light detector are obtained. Hardware of the sending terminal and the receiving terminal is simplified effectively, and meanwhile limitations on light source distribution are reduced.

Description

technical field [0001] The invention relates to the application field of LED optical communication and indoor positioning, in particular to a visible light positioning system and method based on timing marks. Background technique [0002] LED (Lighting Emitting Diode, light-emitting diode) is called the fourth-generation lighting source or green light source. It has the advantages of energy saving, safety, and wide available spectrum. and a series of extended applications. LED-based indoor positioning is one of the application directions with great potential. Since LEDs are placed in a fixed position indoors and have a wide coverage area, the position and distance can be accurately known with each LED as a reference, and GPS-like positioning and navigation can be realized indoors. [0003] Since the LED communication system has the characteristics of optical wireless communication, LED positioning is usually based on RSS (Received Signal Power, received signal strength), AO...

AI Technical Summary

Problems solved by technology

[0004] Because in the RSS-based measurement scheme, different LEDs need to be distinguished and identified by different frequencies or transmission sequences, using different frequencies or transmission sequences for each LED will bring hardware complexity and increase costs

Since the received optical power is usually affected by factors such as the brightness of the light source, the scattering and reflection of signal light, the angle of light transmission and reception, background light interference, etc., the fluctuation of received optical power and various measurement errors will affect the distance estimation and the final positioning result

When the detection distance is short, small distance changes will lead to significant changes in received power. Therefore, the three LEDs with the shortest detection distance and the largest received power are usually selected for three-point positioning, which has certain restrictions on the placement of light sources.

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