{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T10:22:46Z","timestamp":1772274166922,"version":"3.50.1"},"reference-count":43,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2024,8,27]],"date-time":"2024-08-27T00:00:00Z","timestamp":1724716800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the National Natural Science Foundation of China (NSFC)","award":["62371393"],"award-info":[{"award-number":["62371393"]}]},{"name":"the National Natural Science Foundation of China (NSFC)","award":["62471397"],"award-info":[{"award-number":["62471397"]}]},{"name":"the National Natural Science Foundation of China (NSFC)","award":["TCKYS2024604SST3010"],"award-info":[{"award-number":["TCKYS2024604SST3010"]}]},{"name":"the National Natural Science Foundation of China (NSFC)","award":["23GH02027"],"award-info":[{"award-number":["23GH02027"]}]},{"name":"the Stable Supporting Fund of Acoustic Science and Technology Laboratory","award":["62371393"],"award-info":[{"award-number":["62371393"]}]},{"name":"the Stable Supporting Fund of Acoustic Science and Technology Laboratory","award":["62471397"],"award-info":[{"award-number":["62471397"]}]},{"name":"the Stable Supporting Fund of Acoustic Science and Technology Laboratory","award":["TCKYS2024604SST3010"],"award-info":[{"award-number":["TCKYS2024604SST3010"]}]},{"name":"the Stable Supporting Fund of Acoustic Science and Technology Laboratory","award":["23GH02027"],"award-info":[{"award-number":["23GH02027"]}]},{"name":"the Fundamental Research Funds for the Central 359 Universities","award":["62371393"],"award-info":[{"award-number":["62371393"]}]},{"name":"the Fundamental Research Funds for the Central 359 Universities","award":["62471397"],"award-info":[{"award-number":["62471397"]}]},{"name":"the Fundamental Research Funds for the Central 359 Universities","award":["TCKYS2024604SST3010"],"award-info":[{"award-number":["TCKYS2024604SST3010"]}]},{"name":"the Fundamental Research Funds for the Central 359 Universities","award":["23GH02027"],"award-info":[{"award-number":["23GH02027"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Time-varying underwater acoustic (UWA) channels are the key challenge of underwater acoustic communication (UAC). Although UAC exhibits time-variance characteristics significantly in time domains, its delay-Doppler (DD) domain representation tends to be time-invariant. Orthogonal time\u2013frequency space (OTFS) modulation has recently been proposed and has acquired widespread interest due to its excellent performance over time-varying channels. In the UWA OTFS system, the novel DD domain channel estimation algorithm that employs a multidirectional adaptive moving average scheme is proposed. Specifically, the proposed scheme is cascaded by a channel estimator and moving average filter. The channel estimator can be employed to estimate the time-invariant channel of the DD domain multidirectionally, improving proportionate normalized least mean squares (IPNLMS). Meanwhile, the moving average filter is used to reduce the output noise of the IPNLMS. The performance of the proposed method is verified by simulation experiments and real-world lake experiments. The results demonstrate that the proposed channel estimation method can outperform those of benchmark algorithms.<\/jats:p>","DOI":"10.3390\/rs16173157","type":"journal-article","created":{"date-parts":[[2024,8,27]],"date-time":"2024-08-27T03:51:06Z","timestamp":1724730666000},"page":"3157","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Adaptive Channel Estimation Based on Multidirectional Structure in Delay-Doppler Domain for Underwater Acoustic OTFS System"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0847-9701","authenticated-orcid":false,"given":"Wentao","family":"Shi","sequence":"first","affiliation":[{"name":"Ocean Institute, Northwestern Polytechnical University, Taicang 215400, China"},{"name":"School of Marine Science and Technology, Northwestern Polytechnical University, Xi\u2019an 710072, China"}]},{"given":"Mingqi","family":"Jin","sequence":"additional","affiliation":[{"name":"School of Marine Science and Technology, Northwestern Polytechnical University, Xi\u2019an 710072, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8390-3787","authenticated-orcid":false,"given":"Lianyou","family":"Jing","sequence":"additional","affiliation":[{"name":"Ocean Institute, Northwestern Polytechnical University, Taicang 215400, China"}]},{"given":"Nan","family":"Tu","sequence":"additional","affiliation":[{"name":"School of Marine Science and Technology, Northwestern Polytechnical University, Xi\u2019an 710072, China"}]},{"given":"Chengbing","family":"He","sequence":"additional","affiliation":[{"name":"School of Marine Science and Technology, Northwestern Polytechnical University, Xi\u2019an 710072, China"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1109\/MCOM.2009.4752682","article-title":"Underwater acoustic communication channels: Propagation models and statistical characterization","volume":"47","author":"Stojanovic","year":"2009","journal-title":"IEEE Commun. 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