{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T01:20:32Z","timestamp":1760232032873,"version":"build-2065373602"},"reference-count":31,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2022,10,15]],"date-time":"2022-10-15T00:00:00Z","timestamp":1665792000000},"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>In this paper, we present a new multi-user chaos-based communication system using Faster-than-Nyquist sampling to achieve higher data rates and lower energy consumption. The newly designed system, designated Multi-user Faster Than Nyquist Differential Chaos Shift Keying (MU-FTN-DCSK), uses the traditional structure of Differential Chaos Shift Keying (DCSK) communication systems in combination with a filtering system that goes below the Nyquist limit for data sampling. The system is designed to simultaneously enable transmissions from multiple users through multiple sampling rates resulting in semi-orthogonal transmissions. The design, performance analysis, and experimental results of the MU-FTN-DCSK system are presented to demonstrate the utility of the newly proposed system in enabling multi-user communications and enhancing the spectral efficiency of the basic DCSK design without the addition of new blocks. The MU-FTN-DCSK system presented in this paper demonstrates spectral gains for one user of up to 23% and a combined gain of 25% for four (U=4) users. In this paper, we present a proof of concept demonstrating a new degree of freedom in the design of Chaos-based communication systems and their improvement in providing wireless transmissions without complicated signal processing tools or advanced hardware designs.<\/jats:p>","DOI":"10.3390\/s22207837","type":"journal-article","created":{"date-parts":[[2022,10,17]],"date-time":"2022-10-17T03:43:58Z","timestamp":1665978238000},"page":"7837","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Design and Analysis of Multi-User Faster-Than-Nyquist-DCSK Communication Systems over Multi-Path Fading Channels"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6868-8054","authenticated-orcid":false,"given":"Mohamed","family":"Dawa","sequence":"first","affiliation":[{"name":"ETS, LaCIME Laboratory, University of Qu\u00e9bec, 1100 Notre-Dame West, Montreal, QC H3C 1K3, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marijan","family":"Herceg","sequence":"additional","affiliation":[{"name":"Department of Communications, Faculty of Electrical Engineering, Computer Science and Information Technology, 31000 Osijek, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Georges","family":"Kaddoum","sequence":"additional","affiliation":[{"name":"ETS, LaCIME Laboratory, University of Qu\u00e9bec, 1100 Notre-Dame West, Montreal, QC H3C 1K3, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,10,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2621","DOI":"10.1109\/ACCESS.2016.2572730","article-title":"Wireless Chaos-Based Communication Systems: A Comprehensive Survey","volume":"4","author":"Kaddoum","year":"2016","journal-title":"IEEE Access"},{"key":"ref_2","first-page":"321","article-title":"A Generalized Lower Bound on the Bit Error Rate of DCSK Systems Over Multi-Path Rayleigh Fading Channels","volume":"65","author":"Dawa","year":"2018","journal-title":"IEEE Trans. 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