{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,11]],"date-time":"2026-02-11T11:28:42Z","timestamp":1770809322911,"version":"3.50.0"},"reference-count":20,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T00:00:00Z","timestamp":1770336000000},"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>The proliferation of massive antenna arrays and the consequent intensification of near-field effects with 6G necessitate addressing critical security challenges in near-field communication environments. This paper presents a novel artificial noise-aided spatial and directional modulation (SDMN-AN) framework, specifically tailored for secure near-field communications. The proposed system integrates legitimate receiver indices, modulation symbols, and artificial noise (AN) confined to the null space of legitimate channels, thereby enhancing both spectral efficiency and communication security. Two precoding strategies\u2014maximum-ratio transmission (MRT) and zero-forcing (ZF)\u2014are investigated, offering trade-offs between hardware complexity and detection overhead. Analytical derivations of bit error rate (BER) bounds, corroborated by simulation results, underscore the superiority of the SDMN-AN framework in mitigating eavesdropping threats while significantly improving spectral efficiency, positioning it as a compelling solution for next-generation secure wireless networks.<\/jats:p>","DOI":"10.3390\/s26031065","type":"journal-article","created":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T13:33:50Z","timestamp":1770384830000},"page":"1065","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Spatial and Directional Modulation Systems for Near-Field Secure Transmission"],"prefix":"10.3390","volume":"26","author":[{"given":"Ji","family":"Liu","sequence":"first","affiliation":[{"name":"School of Telecommunications Engineering, Xidian University, Xi\u2019an 710126, China"},{"name":"China Academy of Space Technology (Xi\u2019an), Xi\u2019an 710100, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuan","family":"Zhong","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Wireless Communications, University of Electronic Science and Technology of China, Chengdu 611731, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yong","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Telecommunications Engineering, Xidian University, Xi\u2019an 710126, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dong","family":"Gong","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Wireless Communications, University of Electronic Science and Technology of China, Chengdu 611731, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2127-8947","authenticated-orcid":false,"given":"Yue","family":"Xiao","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Wireless Communications, University of Electronic Science and Technology of China, Chengdu 611731, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1109\/MNET.001.1900287","article-title":"A vision of 6G wireless systems: Applications, trends, technologies, and open research problems","volume":"34","author":"Saad","year":"2020","journal-title":"IEEE Netw."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"905","DOI":"10.1109\/COMST.2023.3249835","article-title":"On the Road to 6G: Visions, Requirements, Key Technologies, and Testbeds","volume":"25","author":"Wang","year":"2023","journal-title":"IEEE Commun. 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