Fingerprint quality classification for CSI-based indoor positioning systems

Josyl Mariela Rocamora, Ivan Wang Hei Ho, Man Wai Mak

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

5 Citations (Scopus)


Recent indoor positioning systems that utilize channel state information (CSI) consider ideal scenarios to achieve high-accuracy performance in fingerprint matching. However, one essential component in achieving high accuracy is the collection of high-quality fingerprints. The quality of fingerprints may vary due to uncontrollable factors such as environment noise, interference, and hardware instability. In our paper, we propose a method for collecting high-quality fingerprints for indoor positioning. First, we have developed a logistic regression classifier based on gradient descent to evaluate the quality of the collected channel frequency response (CFR) samples. We employ the classifier to sift out poor CFR samples and only retain good ones as input to the positioning system. We discover that our classifier can achieve high classification accuracy from over thousands of CFR samples. We then evaluate the positioning accuracy based on two techniques: Time-Reversal Resonating Strength (TRRS) and Support Vector Machines (SVM). We find that the sifted fingerprints always result in better positioning performance. For example, an average percentage improvement of 114% for TRRS and 22% for SVM compared to that of unsifted fingerprints of the same 40-MHz effective bandwidth.

Original languageEnglish
Title of host publicationPERSIST-IoT 2019 - Proceedings of the 2019 ACM MobiHoc Workshop on Pervasive Systems in the IoT Era
PublisherAssociation for Computing Machinery
Number of pages6
ISBN (Electronic)9781450368056
Publication statusPublished - 2 Jul 2019
Event2019 ACM MobiHoc Workshop on Pervasive Systems in the IoT Era, PERSIST-IoT 2019 - Catania, Italy
Duration: 2 Jul 2019 → …

Publication series

NameProceedings of the International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc)


Conference2019 ACM MobiHoc Workshop on Pervasive Systems in the IoT Era, PERSIST-IoT 2019
Period2/07/19 → …


  • Channel state information
  • Fingerprint
  • Indoor positioning
  • Logistic regression

ASJC Scopus subject areas

  • Hardware and Architecture
  • Computer Networks and Communications
  • Software


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