# Smartphone User Tracking by Incorporating User Orientation Using a Double-Layer HMM

> Research article (IEEE Transactions on Vehicular Technology, 2022) · cited 12× · AI/ML

**Wikidata**: [openalex:W4226293138](https://www.wikidata.org/wiki/openalex:W4226293138)  
**Source**: https://4ort.xyz/entity/smartphone-user-tracking-by-incorporating-user-orientation-using-a-double-layer-hmm