# Indoor Positioning System Based on Global Positioning System Signals with Down- and Up-Converters in 433 MHz ISM Band

> Research article (Sensors, 2021) · cited 12× · AI/ML

**Wikidata**: [openalex:W3174946636](https://www.wikidata.org/wiki/openalex:W3174946636)  
**Source**: https://4ort.xyz/entity/indoor-positioning-system-based-on-global-positioning-system-signals-with-down-and-up-converters-in-433-mhz-ism-band