RSS-based LED positioning system and method

Abstract

The invention discloses an RSS-based LED positioning system and method, and relates to the field of LED communication and indoor positioning application. The RSS-based LED positioning system comprises at least three sending ends and one receiving end. Each sending end comprises a T-shaped bias device and an LED. The sending ends add PN code sequences before data to be transmitted, and the sequences are converted to visible light for emitting through the T-shaped bias devices and the LEDs; a photo-detector at the receiving end detects visible light signals and converts the visible light signals into electric signals, one FFT unit performs FFT transformation on the electric signals, other FFT units are used for FFT transformation of each PN code, a multiplier performs convolution multiplying on a result and an FFT operation result of each PN code, each product carries out IFFT transformation, a comparison circuit is used for finding out a peak value of time domain signals, and a power-distance conversion module estimates the value of a distance between the receiving end and each LED and outputting the value. According to the invention, multiple orthogonal PN codes are sent for distinguishing different LED sources, such that the hardware complexity of the sending ends is reduced, and the LED bandwidth is decreased.

Description

technical field [0001] The invention relates to the application field of LED optical communication and indoor positioning, in particular to an RSS-based LED positioning system and method. Background technique [0002] LED (Lighting Emitting Diode, light-emitting diode) is called the fourth-generation lighting source or green light source. It has the characteristics of energy saving, environmental protection, long life, and small size. Fields such as lighting and urban night scenes are bound to become the next generation of lighting technology. Because LEDs have the advantages of energy saving, safety, and wide available spectrum, they can also be used in wireless optical communication systems while providing indoor lighting, and at the same time meet indoor Internet access 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 ar...

AI Technical Summary

Problems solved by technology

Based on frequency distinction is the most commonly used method, that is, the signal at the sending end is sent using different frequency carriers, and the receiving end uses filters to filter out different frequency bands and calculate their power. The visible light positioning transmission frequency based on 3 LED positioning is as follows: figure 1 As shown; although this setting distinguishes different signal sources, the hardware customization increases the hardware complexity of the sending end and the receiving end. Different frequency divisions also increase the difficulty of LED placement, and the actual available LED bandwidth becomes limited

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