Unsupervised Learning in RSS-Based DFLT Using an EM Algorithm
Kaltiokallio, Ossi; Hostettler, Roland; Yiğitler, Hüseyin; Valkama, Mikko (2021)
Kaltiokallio, Ossi
Hostettler, Roland
Yiğitler, Hüseyin
Valkama, Mikko
2021
5549
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202110067419
https://urn.fi/URN:NBN:fi:tuni-202110067419
Kuvaus
Peer reviewed
Tiivistelmä
Received signal strength (RSS) changes of static wireless nodes can be used for device-free localization and tracking (DFLT). Most RSS-based DFLT systems require access to calibration data, either RSS measurements from a time period when the area was not occupied by people, or measurements while a person stands in known locations. Such calibration periods can be very expensive in terms of time and effort, making system deployment and maintenance challenging. This paper develops an Expectation-Maximization (EM) algorithm based on Gaussian smoothing for estimating the unknown RSS model parameters, liberating the system from supervised training and calibration periods. To fully use the EM algorithm's potential, a novel localization-and-tracking system is presented to estimate a target's arbitrary trajectory. To demonstrate the effectiveness of the proposed approach, it is shown that: (i) the system requires no calibration period; (ii) the EM algorithm improves the accuracy of existing DFLT methods; (iii) it is computationally very efficient; and (iv) the system outperforms a state-of-the-art adaptive DFLT system in terms of tracking accuracy.
Kokoelmat
- TUNICRIS-julkaisut [16929]