Optical boundaries for LED-based indoor positioning system

Olaoluwa Rotimi Popoola, Sinan Sinanovic, Wasiu O. Popoola, Roberto Ramirez-Iniguez

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)
119 Downloads (Pure)


Overlap of footprints of light emitting diodes (LEDs) increases the positioning accuracy of wearable LED indoor positioning systems (IPS) but such an approach assumes that the footprint boundaries are defined. In this work, we develop a mathematical model for defining the footprint boundaries of an LED in terms of a threshold angle instead of the conventional half or full angle. To show the effect of the threshold angle, we compare how overlaps and receiver tilts affect the performance of an LED-based IPS when the optical boundary is defined at the threshold angle and at the full angle. Using experimental measurements, simulations, and theoretical analysis, the effect of the defined threshold angle is estimated. The results show that the positional time when using the newly defined threshold angle is 12 times shorter than the time when the full angle is used. When the effect of tilt is considered, the threshold angle time is 22 times shorter than the full angle positioning time. Regarding accuracy, it is shown in this work that a positioning error as low as 230 mm can be obtained. Consequently, while the IPS gives a very low positioning error, a defined threshold angle reduces delays in an overlap-based LED IPS.
Original languageEnglish
Article number7
Issue number1
Early online date14 Jan 2019
Publication statusPublished - Mar 2019


  • LED indoor positioning systems
  • mathematical model
  • indoor localization
  • optical wireless communications
  • Infrared protocols
  • Optical wireless communications
  • Indoor localization
  • Light emitting diodes
  • Overlap
  • Optical boundary
  • Packet delivery ratio

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Applied Mathematics
  • General Computer Science
  • Modelling and Simulation


Dive into the research topics of 'Optical boundaries for LED-based indoor positioning system'. Together they form a unique fingerprint.

Cite this