{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T21:46:45Z","timestamp":1790286405130,"version":"4.1.0"},"reference-count":38,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2018,5,29]],"date-time":"2018-05-29T00:00:00Z","timestamp":1527552000000},"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>Channel state information (CSI) collected during WiFi packet transmissions can be used for localization of commodity WiFi devices in indoor environments with multipath propagation. To this end, the angle of arrival (AoA) and time of flight (ToF) for all dominant multipath components need to be estimated. A two-dimensional (2D) version of the multiple signal classification (MUSIC) algorithm has been shown to solve this problem using 2D grid search, which is computationally expensive and is therefore not suited for real-time localisation. In this paper, we propose using a modified matrix pencil (MMP) algorithm instead. Specifically, we show that the AoA and ToF estimates can be found independently of each other using the one-dimensional (1D) MMP algorithm and the results can be accurately paired to obtain the AoA\u2013ToF pairs for all multipath components. Thus, the 2D estimation problem reduces to running 1D estimation multiple times, substantially reducing the computational complexity. We identify and resolve the problem of degenerate performance when two or more multipath components have the same AoA. In addition, we propose a packet aggregation model that uses the CSI data from multiple packets to improve the performance under noisy conditions. Simulation results show that our algorithm achieves two orders of magnitude reduction in the computational time over the 2D MUSIC algorithm while achieving similar accuracy. High accuracy and low computation complexity of our approach make it suitable for applications that require location estimation to run on resource-constrained embedded devices in real time.<\/jats:p>","DOI":"10.3390\/s18061753","type":"journal-article","created":{"date-parts":[[2018,5,30]],"date-time":"2018-05-30T03:04:27Z","timestamp":1527649467000},"page":"1753","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":37,"title":["Estimating Angle-of-Arrival and Time-of-Flight for Multipath Components Using WiFi Channel State Information"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9919-3126","authenticated-orcid":false,"given":"Afaz Uddin","family":"Ahmed","sequence":"first","affiliation":[{"name":"School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, QLD 4072, Australia"},{"name":"Data61, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Pullenvale, QLD 4069, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6932-2900","authenticated-orcid":false,"given":"Reza","family":"Arablouei","sequence":"additional","affiliation":[{"name":"Data61, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Pullenvale, QLD 4069, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Frank","family":"De Hoog","sequence":"additional","affiliation":[{"name":"Data61, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Pullenvale, QLD 4069, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Branislav","family":"Kusy","sequence":"additional","affiliation":[{"name":"Data61, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Pullenvale, QLD 4069, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raja","family":"Jurdak","sequence":"additional","affiliation":[{"name":"Data61, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Pullenvale, QLD 4069, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6279-1053","authenticated-orcid":false,"given":"Neil","family":"Bergmann","sequence":"additional","affiliation":[{"name":"School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, QLD 4072, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,5,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Wang, Z., Yang, Z., and Dong, T. 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