Better positioning of your mobile phone indoors thanks to research by Shengqiang Shen

(21-05-2021) In Shengqiang Shen's doctoral research, algorithms are developed that optimize the positioning of your mobile phone indoors by means of light.

Many wireless applications, used on the mobile phone or other mobile devices, require the knowledge of the position. Outdoors, GPS is used to provide this position information, but indoors, the GPS has poor performance. Therefore, indoor positioning is a research domain that received a large amount of attention during the last twenty years.

Several technologies were considered, e.g. based on WiFi, Bluetooth, cameras or ultra wideband signals, but none of these technologies combine good accuracy with low cost, low energy consumption, privacy and large range.

An indoor positioning technology that solves most of the above mentioned problems is visible light positioning (VLP). This indoor positioning technique is based on the ability of modulating light, i.e. we can periodically change the power of light transmitted by a LED to incorporate information in the light.

An optical sensor then catches the modulated light, from which it extracts the required information, i.e. the position of the sensor. This is how we can build a ‘light’ GPS, where the sensor acts as the GPS device and the LEDs replace the satellites. The received signal not only depends on the position of the sensor, but also on its orientation.

This PhD research by Shengqiang Shen ‘Simultaneous Position and Orientation Estimation for Visible Light Systems with Multiple LEDs and Multiple PDs’ focuses on position and orientation estimation for visible light systems. Various algorithms were developed to deal with the situation where the orientation is not known.

The computer simulations in this research show that the proposed algorithms are effective in position estimation with VLP.

Shengqiang Shen: "Possible applications of my PhD include: routing in large buildings, logistics management of warehouses, supporting healthcare systems, location-based mobile advertising, etc...."

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Public doctoral defence: May 25, 2021

More info via promotor Heidi Steendam

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Editor: Jeroen Ongenae - Final editing: Ilse Vercruysse - Illustration: Roger Van Hecke