{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T14:45:52Z","timestamp":1784213152750,"version":"3.55.0"},"reference-count":30,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T00:00:00Z","timestamp":1760313600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["62171356"],"award-info":[{"award-number":["62171356"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2021YFA1000500"],"award-info":[{"award-number":["2021YFA1000500"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"name":"European Union\u2019s Horizon 2020 Research and Innovation Program","award":["101105732\u2014DDComRad"],"award-info":[{"award-number":["101105732\u2014DDComRad"]}]},{"name":"Bundesministerium f\u00fcr Bildung und Forschung (BMBF) Germany in the program of \u201cSouver\u00e4n. Digital. Vernetzt.\u201d Joint project 6G Research and Innovation Cluster","award":["16KISK030"],"award-info":[{"award-number":["16KISK030"]}]},{"DOI":"10.13039\/501100006764","name":"Technical University of Berlin","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100006764","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>In this paper, a reduced-complexity cross-domain iterative detection for orthogonal time frequency space (OTFS) modulation is proposed that exploits channel properties in both time and delay\u2013Doppler domains. Specifically, we first show that in the time-domain effective channel, the path delay only introduces interference among samples in adjacent time slots, while the Doppler becomes a phase term that does not affect the channel sparsity. This investigation indicates that the effects of delay and Doppler can be decoupled and treated separately. This \u201cband-limited\u201d matrix structure further motivates us to apply a reduced-size linear minimum mean square error (LMMSE) filter to eliminate the effect of delay in the time domain, while exploiting the cross-domain iteration for minimizing the effect of Doppler by noticing that the time and Doppler are a Fourier dual pair. Furthermore, we apply eigenvalue decomposition to the reduced-size LMMSE estimator, which makes the computational complexity independent of the number of cross-domain iterations, thus significantly reducing the computational complexity. The bias evolution and variance evolution are derived to evaluate the average MSE performance of the proposed scheme, which shows that the proposed estimators suffer from only negligible estimation bias in both time and DD domains. Particularly, the state (MSE) evolution is compared with bounds to verify the effectiveness of the proposed scheme. Simulation results demonstrate that the proposed scheme achieves almost the same error performance as the optimal detection, but only requires a reduced complexity.<\/jats:p>","DOI":"10.3390\/e27101062","type":"journal-article","created":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T05:48:21Z","timestamp":1760420901000},"page":"1062","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Cross-Domain OTFS Detection via Delay\u2013Doppler Decoupling: Reduced-Complexity Design and Performance Analysis"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8902-2991","authenticated-orcid":false,"given":"Mengmeng","family":"Liu","sequence":"first","affiliation":[{"name":"State Key Laboratory of ISN, Xidian University, Xi\u2019an 710071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9503-4865","authenticated-orcid":false,"given":"Shuangyang","family":"Li","sequence":"additional","affiliation":[{"name":"Electrical Engineering and Computer Science Department, Technische Universit\u00e4t Berlin, 10587 Berlin, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6161-5493","authenticated-orcid":false,"given":"Baoming","family":"Bai","sequence":"additional","affiliation":[{"name":"State Key Laboratory of ISN, Xidian University, Xi\u2019an 710071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giuseppe","family":"Caire","sequence":"additional","affiliation":[{"name":"Electrical Engineering and Computer Science Department, Technische Universit\u00e4t Berlin, 10587 Berlin, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1007\/s11432-020-2955-6","article-title":"Towards 6G wireless communication networks: Vision, enabling technologies, and new paradigm shifts","volume":"64","author":"You","year":"2021","journal-title":"Sci. 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