{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:41:55Z","timestamp":1760114515811,"version":"build-2065373602"},"reference-count":33,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2024,9,19]],"date-time":"2024-09-19T00:00:00Z","timestamp":1726704000000},"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":"publisher","award":["62271286"],"award-info":[{"award-number":["62271286"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The use of conformal arrays offers a significant advancement in Multiple-Input\u2013Multiple-Output (MIMO) radar, enabling the placement of antennas on irregular surfaces. For joint Direction-of-Departure (DOD) and Direction-of-Arrival (DOA) estimation in conformal-array MIMO radar, the current spectrum-searching methods are computationally too expensive, while the existing rotation-invariant method may suffer from phase ambiguity caused by the non-Nyquist spacing of the sensors. In this paper, an improved rotationally invariant technique is proposed. The core function of the proposed algorithm is to estimate the phase differences between the adjacent sensors; then, it eliminates phase ambiguity via the previous estimated standard phase difference. Thereafter, DODs and DOAs are obtained via Least Squares (LS) fitting. The proposed method provides closed-form estimates for joint DOD and DOA estimation, which is much more efficient than the existing spectrum-searching techniques. Numerical simulations show that the proposed algorithm can accurately determine 2D DODs and DOAs of targets, only requiring approximately 1% of the running time required by existing spectrum-searching approaches.<\/jats:p>","DOI":"10.3390\/s24186065","type":"journal-article","created":{"date-parts":[[2024,9,19]],"date-time":"2024-09-19T09:23:04Z","timestamp":1726737784000},"page":"6065","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Computationally Efficient Direction Finding for Conformal MIMO Radar"],"prefix":"10.3390","volume":"24","author":[{"given":"Haochen","family":"Wang","sequence":"first","affiliation":[{"name":"Department of Communication Technologies and System Design, Technical University of Denmark (DTU), 2800 Lyngby, Denmark"}]},{"given":"Zhiyu","family":"Yu","sequence":"additional","affiliation":[{"name":"School of Microelectronics and Communication Engineering, Chongqing University, Chongqing 401331, China"}]},{"given":"Fangqing","family":"Wen","sequence":"additional","affiliation":[{"name":"College of Computer and Information Technology, China Three Gorges University, Yichang 443002, China"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Ruan, N., Wang, H., Wen, F., and Shi, J. 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