{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,8]],"date-time":"2026-02-08T08:32:33Z","timestamp":1770539553377,"version":"3.49.0"},"reference-count":38,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2020,9,29]],"date-time":"2020-09-29T00:00:00Z","timestamp":1601337600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Currently, visible light positioning (VLP) enabling an illumination infrastructure requires a costly retrofit. Intensity modulation systems not only necessitate changes to the internal LED driving module, but decrease the LEDs\u2019 radiant flux as well. This hinders the infrastructure\u2019s ability to meet the maintained illuminance standards. Ideally, the LEDs could be left unmodulated, i.e., unmodulated VLP (uVLP). uVLP systems, inherently low-cost, exploit the characteristics of the light signals of opportunity (LSOOP) to infer a position. In this paper, it is shown that proper signal processing allows using the LED\u2019s characteristic frequency (CF) as a discriminative feature in photodiode (PD)-based received signal strength (RSS) uVLP. This manuscript investigates and compares the aptitude of (future) RSS-based uVLP and VLP systems in terms of their feasibility, cost and accuracy. It demonstrates that CF-based uVLP exhibits an acceptable loss of accuracy compared to (regular) VLP. For point source-like LEDs, uVLP only worsens the trilateration-based median p50 and 90th percentile root-mean-square error p90 from 5.3cm to 7.9cm (+50%) and from 9.6cm to 15.6cm (+62%), in the 4m \u00d7 4m room under consideration. A large experimental validation shows that employing a robust model-based fingerprinting localisation procedure, instead of trilateration, further boosts uVLP\u2019s p50 and p90 accuracy to 5.0cm and 10.6cm. When collating with VLP\u2019s p50=3.5cm and p90=6.8cm, uVLP exhibits a comparable positioning performance at a significantly lower cost and at a higher maintained illuminance, all of which underline uVLP\u2019s high adoption potential. With this work, a significant step is taken towards the development of an accurate and low-cost tracking system.<\/jats:p>","DOI":"10.3390\/s20195596","type":"journal-article","created":{"date-parts":[[2020,9,29]],"date-time":"2020-09-29T20:56:22Z","timestamp":1601412982000},"page":"5596","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["A Comprehensive Study on Light Signals of Opportunity for Subdecimetre Unmodulated Visible Light Positioning"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6797-6778","authenticated-orcid":false,"given":"Sander","family":"Bastiaens","sequence":"first","affiliation":[{"name":"WAVES, Department of Information Technology, Ghent University\/imec, Technologiepark-Zwijnaarde 126, B-9052 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1954-6738","authenticated-orcid":false,"given":"Kenneth","family":"Deprez","sequence":"additional","affiliation":[{"name":"WAVES, Department of Information Technology, Ghent University\/imec, Technologiepark-Zwijnaarde 126, B-9052 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9948-9157","authenticated-orcid":false,"given":"Luc","family":"Martens","sequence":"additional","affiliation":[{"name":"WAVES, Department of Information Technology, Ghent University\/imec, Technologiepark-Zwijnaarde 126, B-9052 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8807-0673","authenticated-orcid":false,"given":"Wout","family":"Joseph","sequence":"additional","affiliation":[{"name":"WAVES, Department of Information Technology, Ghent University\/imec, Technologiepark-Zwijnaarde 126, B-9052 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8879-5076","authenticated-orcid":false,"given":"David","family":"Plets","sequence":"additional","affiliation":[{"name":"WAVES, Department of Information Technology, Ghent University\/imec, Technologiepark-Zwijnaarde 126, B-9052 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,9,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Rahman, A.B.M., Li, T., and Wang, Y. 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