{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T20:19:45Z","timestamp":1773778785721,"version":"3.50.1"},"reference-count":22,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,5,6]],"date-time":"2023-05-06T00:00:00Z","timestamp":1683331200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["62271503"],"award-info":[{"award-number":["62271503"]}]},{"name":"National Natural Science Foundation of China","award":["62071485"],"award-info":[{"award-number":["62071485"]}]},{"name":"National Natural Science Foundation of China","award":["62001513"],"award-info":[{"award-number":["62001513"]}]},{"name":"National Natural Science Foundation of China","award":["BK 20192002"],"award-info":[{"award-number":["BK 20192002"]}]},{"name":"National Natural Science Foundation of China","award":["BK 20201334"],"award-info":[{"award-number":["BK 20201334"]}]},{"name":"National Natural Science Foundation of China","award":["BK 20200579"],"award-info":[{"award-number":["BK 20200579"]}]},{"name":"Basic Research Project of Jiangsu Province","award":["62271503"],"award-info":[{"award-number":["62271503"]}]},{"name":"Basic Research Project of Jiangsu Province","award":["62071485"],"award-info":[{"award-number":["62071485"]}]},{"name":"Basic Research Project of Jiangsu Province","award":["62001513"],"award-info":[{"award-number":["62001513"]}]},{"name":"Basic Research Project of Jiangsu Province","award":["BK 20192002"],"award-info":[{"award-number":["BK 20192002"]}]},{"name":"Basic Research Project of Jiangsu Province","award":["BK 20201334"],"award-info":[{"award-number":["BK 20201334"]}]},{"name":"Basic Research Project of Jiangsu Province","award":["BK 20200579"],"award-info":[{"award-number":["BK 20200579"]}]},{"name":"Natural Science Foundation of Jiangsu Province","award":["62271503"],"award-info":[{"award-number":["62271503"]}]},{"name":"Natural Science Foundation of Jiangsu Province","award":["62071485"],"award-info":[{"award-number":["62071485"]}]},{"name":"Natural Science Foundation of Jiangsu Province","award":["62001513"],"award-info":[{"award-number":["62001513"]}]},{"name":"Natural Science Foundation of Jiangsu Province","award":["BK 20192002"],"award-info":[{"award-number":["BK 20192002"]}]},{"name":"Natural Science Foundation of Jiangsu Province","award":["BK 20201334"],"award-info":[{"award-number":["BK 20201334"]}]},{"name":"Natural Science Foundation of Jiangsu Province","award":["BK 20200579"],"award-info":[{"award-number":["BK 20200579"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Orthogonal time\u2013frequency space (OTFS) modulation has been advocated as a promising waveform for achieving integrated sensing and communication (ISAC) due to its superiority in high-mobility adaptability and spectral efficiency. In OTFS modulation-based ISAC systems, accurate channel acquisition is critical for both communication reception and sensing parameter estimation. However, the existence of the fractional Doppler frequency shift spreads the effective channels of the OTFS signal significantly, making efficient channel acquisition very challenging. In this paper, we first derive the sparse structure of the channel in the delay Doppler (DD) domain according to the input and output relationship of OTFS signals. On this basis, a new structured Bayesian learning approach is proposed for accurate channel estimation, which includes a novel structured prior model for the delay-Doppler channel and a successive majorization\u2013minimization (SMM) algorithm for efficient posterior channel estimate computation. Simulation results show that the proposed approach significantly outperforms the reference schemes, especially in the low signal-to-noise ratio (SNR) region.<\/jats:p>","DOI":"10.3390\/e25050761","type":"journal-article","created":{"date-parts":[[2023,5,8]],"date-time":"2023-05-08T03:00:28Z","timestamp":1683514828000},"page":"761","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["A Structured Sparse Bayesian Channel Estimation Approach for Orthogonal Time\u2014Frequency Space Modulation"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2138-0706","authenticated-orcid":false,"given":"Mi","family":"Zhang","sequence":"first","affiliation":[{"name":"School of Communication Engineering, Army Engineering University of PLA, Nanjing 210007, China"}]},{"given":"Xiaochen","family":"Xia","sequence":"additional","affiliation":[{"name":"School of Communication Engineering, Army Engineering University of PLA, Nanjing 210007, China"}]},{"given":"Kui","family":"Xu","sequence":"additional","affiliation":[{"name":"School of Communication Engineering, Army Engineering University of PLA, Nanjing 210007, China"}]},{"given":"Xiaoqin","family":"Yang","sequence":"additional","affiliation":[{"name":"School of Communication Engineering, Army Engineering University of PLA, Nanjing 210007, China"}]},{"given":"Wei","family":"Xie","sequence":"additional","affiliation":[{"name":"School of Communication Engineering, Army Engineering University of PLA, Nanjing 210007, China"}]},{"given":"Yunkun","family":"Li","sequence":"additional","affiliation":[{"name":"Unit 31105 of PLA, Nanjing 210042, China"}]},{"given":"Yang","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Communication Engineering, Army Engineering University of PLA, Nanjing 210007, China"}]}],"member":"1968","published-online":{"date-parts":[[2023,5,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1109\/JCN.2018.000010","article-title":"Low-delay broadband satellite communications with high-altitude unmanned aerial vehicles","volume":"20","author":"Joo","year":"2018","journal-title":"J. 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