{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T23:26:25Z","timestamp":1784676385533,"version":"3.55.0"},"reference-count":31,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2020,6,27]],"date-time":"2020-06-27T00:00:00Z","timestamp":1593216000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006595","name":"Unitatea Executiva pentru Finantarea Invatamantului Superior, a Cercetarii, Dezvoltarii si Inovarii","doi-asserted-by":"publisher","award":["PN-III-P1-1.1-PD-2016-1696"],"award-info":[{"award-number":["PN-III-P1-1.1-PD-2016-1696"]}],"id":[{"id":"10.13039\/501100006595","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Implementation of dynamic spectrum access (DSA) in cognitive radio (CR) systems requires the unlicensed secondary users (SU) to implement spectrum sensing to monitor the activity of the licensed primary users (PU). Energy detection (ED) is one of the most widely used methods for spectrum sensing in CR systems, and in this paper we present a novel ED algorithm with an adaptive sensing threshold. The three-event ED (3EED) algorithm for spectrum sensing is considered for which an accurate approximation of the optimal decision threshold that minimizes the decision error probability (DEP) is found using Newton\u2019s method with forced convergence in one iteration. The proposed algorithm is analyzed and illustrated with numerical results obtained from simulations that closely match the theoretical results and show that it outperforms the conventional ED (CED) algorithm for spectrum sensing.<\/jats:p>","DOI":"10.3390\/s20133614","type":"journal-article","created":{"date-parts":[[2020,6,29]],"date-time":"2020-06-29T11:17:17Z","timestamp":1593429437000},"page":"3614","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":25,"title":["Three-Event Energy Detection with Adaptive Threshold for Spectrum Sensing in Cognitive Radio Systems"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5324-7195","authenticated-orcid":false,"given":"Alexandru","family":"Martian","sequence":"first","affiliation":[{"name":"Telecommunications Department, Polytechnic University of Bucharest, 061071 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mahmood Jalal Ahmad","family":"Al Sammarraie","sequence":"additional","affiliation":[{"name":"Telecommunications Department, Polytechnic University of Bucharest, 061071 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4213-6411","authenticated-orcid":false,"given":"C\u0103lin","family":"Vl\u0103deanu","sequence":"additional","affiliation":[{"name":"Telecommunications Department, Polytechnic University of Bucharest, 061071 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dimitrie C.","family":"Popescu","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,6,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2386","DOI":"10.1109\/COMST.2016.2559525","article-title":"Spectrum Occupancy Measurements: A Survey and Use of Interference Maps","volume":"18","author":"Eskola","year":"2016","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_2","first-page":"693","article-title":"Access to RF White Spaces in Romania: Present and Future","volume":"86","author":"Vulpe","year":"2016","journal-title":"Wirel. Pers. Commun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1109\/MSP.2007.361604","article-title":"A Survey of Dynamic Spectrum Access","volume":"24","author":"Zhao","year":"2007","journal-title":"IEEE Signal Process. Mag."},{"key":"ref_4","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_5","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1109\/TCOMM.2006.887483","article-title":"On the Energy Detection of Unknown Signals Over Fading Channels","volume":"55","author":"Digham","year":"2007","journal-title":"IEEE Trans. Commun."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Cao, K., Qian, P., An, J., and Wang, L. (2020). Accurate and Practical Energy Detection over \u03b1 \u2212 \u03bc Fading Channels. Sensors, 20.","DOI":"10.3390\/s20030754"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Wasilewska, M., and Bogucka, H. (2019). Machine Learning for LTE Energy Detection Performance Improvement. Sensors, 19.","DOI":"10.3390\/s19194348"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Huang, H., Zhu, J., and Mu, J. (2019). A Novel Sensing Strategy Based on Energy Detector for Spectrum Sensing. Appl. Sci., 9.","DOI":"10.3390\/app9214634"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1784","DOI":"10.1109\/TCOMM.2009.06.070402","article-title":"Eigenvalue-Based Spectrum Sensing Algorithms for Cognitive Radio","volume":"57","author":"Zeng","year":"2009","journal-title":"IEEE Trans. Commun."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"462","DOI":"10.1109\/TCCN.2018.2816642","article-title":"Grassmann Manifold-Based Spectrum Sensing for TV White Spaces","volume":"4","author":"Bishnu","year":"2018","journal-title":"IEEE Trans. Cogn. Commun. Netw."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"5137","DOI":"10.1109\/TVT.2014.2379924","article-title":"Spectrum Sensing Using Weighted Covariance Matrix in Rayleigh Fading Channels","volume":"64","author":"Jin","year":"2015","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"823","DOI":"10.1109\/TIM.2014.2357592","article-title":"Second-Order Cyclostationarity-Based Detection of LTE SC-FDMA Signals for Cognitive Radio Systems","volume":"64","author":"Jerjawi","year":"2015","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1109\/JSTSP.2011.2174773","article-title":"Second-Order Cyclostationarity of Mobile WiMAX and LTE OFDM Signals and Application to Spectrum Awareness in Cognitive Radio Systems","volume":"6","author":"Dobre","year":"2012","journal-title":"IEEE J. Sel. Top. Signal Process."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1838","DOI":"10.1109\/COMST.2016.2524443","article-title":"Application of Compressive Sensing in Cognitive Radio Communications: A Survey","volume":"18","author":"Sharma","year":"2016","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Arjoune, Y., and Kaabouch, N. (2018). Wideband Spectrum Sensing: A Bayesian Compressive Sensing Approach. Sensors, 18.","DOI":"10.3390\/s18061839"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Arjoune, Y., and Kaabouch, N. (2019). A Comprehensive Survey on Spectrum Sensing in Cognitive Radio Networks: Recent Advances, New Challenges, and Future Research Directions. Sensors, 19.","DOI":"10.3390\/s19010126"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1109\/JSTSP.2007.914879","article-title":"SNR Walls for Signal Detection","volume":"2","author":"Tandra","year":"2008","journal-title":"IEEE J. Sel. Top. Signal Process."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1049\/iet-com.2010.0571","article-title":"Improved Energy Detection Spectrum Sensing for Cognitive Radio","volume":"6","author":"Casadevall","year":"2012","journal-title":"IET Commun."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1109\/LWC.2016.2543723","article-title":"Energy Detection Algorithm for Spectrum Sensing Using Three Consecutive Sensing Events","volume":"5","year":"2016","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1109\/JSYST.2017.2759222","article-title":"Improved Energy Detection With Laplacian Noise in Cognitive Radio","volume":"13","author":"Ye","year":"2019","journal-title":"IEEE Syst. J."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1049\/iet-spr.2013.0105","article-title":"Enhanced Spectrum Utilization in Dynamic Cognitive Radios with Adaptive Sensing","volume":"8","author":"Treeumnuk","year":"2014","journal-title":"IET Signal Process."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1838","DOI":"10.1109\/LCOMM.2013.081313.131468","article-title":"Adaptive Spectrum Sensing Algorithm Under Different Primary User Utilizations","volume":"17","author":"Wang","year":"2013","journal-title":"IEEE Commun. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1109\/LCOMM.2010.11.100654","article-title":"Gradient-Based Threshold Adaptation for Energy Detector in Cognitive Radio Systems","volume":"15","author":"Joshi","year":"2011","journal-title":"IEEE Commun. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Sammarraie, M.J.A.A., Mar\u0163ian, A., and Vl\u0103deanu, C. (2018, January 8\u20139). A Modified 3EED Spectrum Sensing Algorithm Using an Adaptive Decision Threshold. Proceedings of the 2018 International Symposium on Electronics and Telecommunications (ISETC), Timisoara, Romania.","DOI":"10.1109\/ISETC.2018.8583880"},{"key":"ref_25","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_26","unstructured":"Yates, R.D., and Goodman, D.J. (1999). Probability and Stochastic Processes. A Friendly Introduction for Electrical and Computer Engineers, John Wiley and Sons, Inc.. [1st ed.]."},{"key":"ref_27","unstructured":"Antoniou, A., and Lu, W.S. (2007). Practical Optimization: Algorithms and Engineering Applications, Springer Science and Business Media. [1st ed.]."},{"key":"ref_28","unstructured":"Epperson, J.F. (2013). An Introduction to Numerical Methods and Analysis, John Wiley and Sons, Inc.. [2nd ed.]."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1109\/LCOMM.2007.070470","article-title":"An Improved Approximation for the Gaussian Q-Function","volume":"11","author":"Karagiannidis","year":"2007","journal-title":"IEEE Commun. Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"731","DOI":"10.1109\/TCCN.2017.2771558","article-title":"RF-Spectrum Opportunities for Cognitive Radio Networks Operating Over GSM Channels","volume":"3","author":"Oliveira","year":"2017","journal-title":"IEEE Trans. Cogn. Commun. Netw."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2555","DOI":"10.1109\/JSAC.2013.131114","article-title":"On the Measurement of Duty Cycle and Channel Occupancy Rate","volume":"31","author":"Lehtomaki","year":"2013","journal-title":"IEEE J. Sel. Areas Commun."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/13\/3614\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:43:33Z","timestamp":1760175813000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/13\/3614"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,6,27]]},"references-count":31,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2020,7]]}},"alternative-id":["s20133614"],"URL":"https:\/\/doi.org\/10.3390\/s20133614","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,6,27]]}}}