{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T13:36:57Z","timestamp":1776260217600,"version":"3.50.1"},"reference-count":20,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2012,11,8]],"date-time":"2012-11-08T00:00:00Z","timestamp":1352332800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In the cognitive radio system, spectrum sensing for detecting the presence of primary users in a licensed spectrum is a fundamental problem. Energy detection is the most popular spectrum sensing scheme used to differentiate the case where the primary user\u2019s signal is present from the case where there is only noise. In fact, the nature of spectrum sensing can be taken as a binary classification problem, and energy detection is a linear classifier. If the signal-to-noise ratio (SNR) of the received signal is low, and the number of received signal samples for sensing is small, the binary classification problem is linearly inseparable. In this situation the performance of energy detection will decrease seriously. In this paper, a novel approach for obtaining a nonlinear threshold based on support vector machine with particle swarm optimization (PSO-SVM) to replace the linear threshold used in traditional energy detection is proposed. Simulations demonstrate that the performance of the proposed algorithm is much better than that of traditional energy detection.<\/jats:p>","DOI":"10.3390\/s121115292","type":"journal-article","created":{"date-parts":[[2012,11,8]],"date-time":"2012-11-08T11:04:29Z","timestamp":1352372669000},"page":"15292-15307","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["A Modular Spectrum Sensing System Based on PSO-SVM"],"prefix":"10.3390","volume":"12","author":[{"given":"Zhuoran","family":"Cai","sequence":"first","affiliation":[{"name":"School of Electronics and Information Technology, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Honglin","family":"Zhao","sequence":"additional","affiliation":[{"name":"School of Electronics and Information Technology, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhutian","family":"Yang","sequence":"additional","affiliation":[{"name":"School of Electronics and Information Technology, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yun","family":"Mo","sequence":"additional","affiliation":[{"name":"School of Electronics and Information Technology, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2012,11,8]]},"reference":[{"key":"ref_1","unstructured":"(2002). Spectrum Policy Task Force Report; Technical Report TR 02-155, Federal Communications Commission."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1109\/98.788210","article-title":"Cognitive radio: Making software radios more personal","volume":"6","author":"Mitola","year":"1999","journal-title":"IEEE Personal Commun."},{"key":"ref_3","unstructured":"Mitola, J. (2000). Cognitive Radio: An Integrated Agent Architecture for Software Defined Radio. [Ph.D. Thesis, Royal Institute of Technology (KTH)]."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1109\/JSAC.2004.839380","article-title":"Cognitive radio: Brain-Empowered wireless communications","volume":"23","author":"Haykin","year":"2005","journal-title":"IEEE J. Sel. Area Commun."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1326","DOI":"10.1109\/TWC.2008.060869","article-title":"Sensing-throughput tradeoff for cognitive radio networks","volume":"7","author":"Liang","year":"2008","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_6","unstructured":"Kay, S. (1998). Fundamentals of Statistical Signal Processing: Detection Theory, Prentice-Hall. [1st ed.]."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1109\/JSTSP.2007.914882","article-title":"Optimal linear cooperation for spectrum sensing in cognitive radio networks","volume":"2","author":"Quan","year":"2008","journal-title":"IEEE J. Sel. Top. Signal Process."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1109\/JSTSP.2010.2055537","article-title":"Optimization of linear cooperative spectrum sensing for cognitive radio networks","volume":"5","author":"Taricco","year":"2011","journal-title":"IEEE J. Sel. Top. Signal Process."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1109\/PROC.1967.5573","article-title":"Energy detection of unknown deterministic signals","volume":"55","author":"Urkowitz","year":"1967","journal-title":"Proc. IEEE"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"654","DOI":"10.1109\/7.256287","article-title":"Radiometric detection of spread-spectrum signals in noise of uncertainty power","volume":"28","author":"Sonnenschein","year":"1992","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_11","unstructured":"Sahai, A., and Cabric, D. (November, January 8\u2013). Spectrum Sensing: Fundamental Limits and Practical Challenges. Baltimore, MD, USA."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1109\/79.81007","article-title":"Exploitation of spectral redundancy in cyclostationary signals","volume":"8","author":"Gardner","year":"1991","journal-title":"IEEE Signal Process. Mag."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1109\/TCOM.1987.1096816","article-title":"Spectral correlation of modulated signals\u2014Part II: Digital modulation","volume":"35","author":"Gardner","year":"1987","journal-title":"IEEE Trans. Commun."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1804","DOI":"10.1109\/TVT.2008.2005267","article-title":"Spectrum\u2014Sensing algorithms for cognitive radio based on statistical covariances","volume":"58","author":"Zeng","year":"2009","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Chen, H.S., Gao, W., and Daut, D.G. (2007, January 24\u201328). Signature Based Spectrum Sensing Algorithms for IEEE 802.22 WRAN. Glasgow, UK.","DOI":"10.1109\/ICC.2007.1073"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Vapnik, V.N. (1995). The Nature of Statistical Learning Theory, Springer-Verlag. [1st ed.].","DOI":"10.1007\/978-1-4757-2440-0"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1055","DOI":"10.1109\/72.788646","article-title":"Support vector machines for histogram-based image classification","volume":"10","author":"Chapelle","year":"1999","journal-title":"IEEE Trans. Neural Netw."},{"key":"ref_18","unstructured":"Kuhn, H., and Tucker, A. (August, January 31). Nonlinear Programming. Berkeley, CA, USA."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1427","DOI":"10.3923\/itj.2011.1427.1431","article-title":"Spectrum sensing in cognitive radio based on adaptive optimal SVM","volume":"10","author":"Cai","year":"2011","journal-title":"Inform. Technol. J."},{"key":"ref_20","first-page":"202","article-title":"The noncentral \u03c72 and F distributions and their applications","volume":"36","author":"Patnaik","year":"1949","journal-title":"Biometrika"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/12\/11\/15292\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:53:25Z","timestamp":1760219605000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/12\/11\/15292"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012,11,8]]},"references-count":20,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2012,11]]}},"alternative-id":["s121115292"],"URL":"https:\/\/doi.org\/10.3390\/s121115292","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012,11,8]]}}}