{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T14:08:53Z","timestamp":1772114933253,"version":"3.50.1"},"reference-count":45,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2020,6,16]],"date-time":"2020-06-16T00:00:00Z","timestamp":1592265600000},"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>Non-contact detection and estimation of vital signs such as respiratory and cardiac frequencies is a powerful tool for surveillance applications. In particular, the continuous wave bio-radar has been widely investigated to determine the physiological parameters in a non-contact manner. Since the RF-reflected signal from the human body is corrupted by noise and random body movements, traditional Fourier analysis fails to detect the heart and breathing frequencies. In this effort, cyclostationary analysis has been used to improve the radar performance for non-invasive measurement of respiratory rate and heart rate. However, the preliminary works focus only on one frequency and do not include the impact of attenuation and random movement of the body in the analysis. Hence in this paper, we evaluate the impact of distance and noise on the cyclic features of the reflected signal. Furthermore, we explore the assessment of second order cyclostationary signal processing performance by developing the cyclic mean, the conjugate cyclic autocorrelation and the cyclic cumulant. In addition, the analysis is carried out using a reduced number of samples to reduce the response time. Implementation of the cyclostationary technique using a bi-static radar configuration at 2.5 GHz is shown as an example to demonstrate the proposed approach.<\/jats:p>","DOI":"10.3390\/s20123396","type":"journal-article","created":{"date-parts":[[2020,6,16]],"date-time":"2020-06-16T13:20:43Z","timestamp":1592313643000},"page":"3396","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Cyclostationary-Based Vital Signs Detection Using Microwave Radar at 2.5 GHz"],"prefix":"10.3390","volume":"20","author":[{"given":"Fatima","family":"Sekak","sequence":"first","affiliation":[{"name":"CNRS, UMR 8520\u2013IEMN groupe CSAM (Systems Circuits Microwave Applications), University of Lille, F-59000 Lille, France"},{"name":"Groupe LEOST (Electronic Wave and Signal Laboratory for Transport), University of Gustave Eiffel, F-59666 Villeneuve d\u2019 Ascq, France"},{"name":"Segula Engineering France, 92500 Rueil-Malmaison, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kawtar","family":"Zerhouni","sequence":"additional","affiliation":[{"name":"Groupe LEOST (Electronic Wave and Signal Laboratory for Transport), University of Gustave Eiffel, F-59666 Villeneuve d\u2019 Ascq, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fouzia","family":"Elbahhar","sequence":"additional","affiliation":[{"name":"Groupe LEOST (Electronic Wave and Signal Laboratory for Transport), University of Gustave Eiffel, F-59666 Villeneuve d\u2019 Ascq, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Madjid","family":"Haddad","sequence":"additional","affiliation":[{"name":"Segula Engineering France, 92500 Rueil-Malmaison, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6882-7993","authenticated-orcid":false,"given":"Christophe","family":"Loyez","sequence":"additional","affiliation":[{"name":"CNRS, UMR 8520\u2013IEMN groupe CSAM (Systems Circuits Microwave Applications), University of Lille, F-59000 Lille, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kamel","family":"Haddadi","sequence":"additional","affiliation":[{"name":"CNRS, UMR 8520\u2013IEMN groupe CSAM (Systems Circuits Microwave Applications), University of Lille, F-59000 Lille, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,6,16]]},"reference":[{"key":"ref_1","first-page":"68","article-title":"ECG signal analysis using wavelet transforms","volume":"35","author":"Saritha","year":"2008","journal-title":"Bulg. J. Phys."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1002\/ppul.21416","article-title":"Respiration rate monitoring methods: A review","volume":"46","author":"Saatchi","year":"2011","journal-title":"Pediatr. Pulmonol."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Aarts, V., Dellimore, K.H., Wijshoff, R., Derkx, R., van de Laar, J., and Muehlsteff, J. (2017, January 9\u201312). Performance of an accelerometer-based pulse presence detection approach compared to a reference sensor. Proceedings of the 2017 IEEE 14th International Conference on Wearable and Implantable Body Sensor Networks (BSN), Eindhoven, The Netherlands.","DOI":"10.1109\/BSN.2017.7936033"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Giovangrandi, L., Inan, O.T., Banerjee, D., and Kovacs, G.T. (September, January 28). Preliminary results from BCG and ECG measurements in the heart failure clinic. Proceedings of the 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, San Diego, CA, USA.","DOI":"10.1109\/EMBC.2012.6346790"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1055\/s-0039-1677914","article-title":"A broader look: Camera-based vital sign estimation across the spectrum","volume":"28","author":"Antink","year":"2019","journal-title":"Yearb. Med. Inform."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"328","DOI":"10.1016\/j.sna.2012.10.021","article-title":"Development of a piezoelectric polyvinylidene fluoride (PVDF) polymer-based sensor patch for simultaneous heartbeat and respiration monitoring","volume":"189","author":"Chiu","year":"2013","journal-title":"Sensors Actuators A Phys."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"13088","DOI":"10.3390\/s140713088","article-title":"An optical fibre-based sensor for respiratory monitoring","volume":"14","author":"Krehel","year":"2014","journal-title":"Sensors"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Dias, D., and Paulo Silva Cunha, J. (2018). Wearable health devices\u2014vital sign monitoring, systems and technologies. Sensors, 18.","DOI":"10.3390\/s18082414"},{"key":"ref_9","unstructured":"Droitcour, A., Lubecke, V., Lin, J., and Boric-Lubecke, O. (2001, January 20\u201324). A microwave radio for Doppler radar sensing of vital signs. Proceedings of the 2001 IEEE MTT-S International Microwave Sympsoium Digest (Cat. No. 01CH37157), Phoenix, AZ, USA."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1109\/19.85346","article-title":"Automatic clutter-canceler for microwave life-detection systems","volume":"40","author":"Chuang","year":"1991","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1530","DOI":"10.1109\/PROC.1975.9992","article-title":"Noninvasive microwave measurement of respiration","volume":"63","author":"Lin","year":"1975","journal-title":"Proc. IEEE"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Michler, F., Shi, K., Schellenberger, S., Steigleder, T., Malessa, A., Hameyer, L., Neumann, N., Lurz, F., Ostgathe, C., and Weigel, R. (2019). A clinically evaluated interferometric continuous-wave radar system for the contactless measurement of human vital parameters. Sensors, 19.","DOI":"10.3390\/s19112492"},{"key":"ref_13","unstructured":"Chioukh, L., Boutayeb, H., Wu, K., and Deslandes, D. (2011, January 10\u201313). Monitoring vital signs using remote harmonic radar concept. Proceedings of the 2011 41st European Microwave Conference, Manchester, UK."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Zhang, T., Sarrazin, J., Valerio, G., and Istrate, D. (2018). Estimation of human body vital signs based on 60 GHz Doppler radar using a bound-constrained optimization algorithm. Sensors, 18.","DOI":"10.3390\/s18072254"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Koelpin, A., Lurz, F., Linz, S., Mann, S., Will, C., and Lindner, S. (2016). Six-port based interferometry for precise radar and sensing applications. Sensors, 16.","DOI":"10.3390\/s16101556"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2093","DOI":"10.1109\/TMTT.2013.2247055","article-title":"Six-port radar sensor for remote respiration rate and heartbeat vital-sign monitoring","volume":"61","author":"Vinci","year":"2013","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1334","DOI":"10.1109\/TMTT.2016.2633352","article-title":"A portable FMCW interferometry radar with programmable low-IF architecture for localization, ISAR imaging, and vital sign tracking","volume":"65","author":"Peng","year":"2016","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Lee, H., Kim, B.H., Park, J.K., and Yook, J.G. (2019). A Novel Vital-Sign sensing algorithm for multiple subjects based on 24-GHz FMCW doppler radar. Remote Sens., 11.","DOI":"10.3390\/rs11101237"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Wang, J., Tang, Y., Mu\u00f1oz-Ferreras, J.M., G\u00f3mez-Garc\u00eda, R., and Li, C. (2018, January 14\u201317). An improved indoor localization solution using a hybrid UWB-Doppler system with Kalman filter. Proceedings of the 2018 IEEE Radio and Wireless Symposium (RWS), Anaheim, CA, USA.","DOI":"10.1109\/RWS.2018.8304980"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Khan, F., and Cho, S.H. (2017). A detailed algorithm for vital sign monitoring of a stationary\/non-stationary human through IR-UWB radar. Sensors, 17.","DOI":"10.3390\/s17020290"},{"key":"ref_21","unstructured":"Rivera, N.V., Venkatesh, S., Anderson, C., and Buehrer, R.M. (2006, January 4\u20138). Multi-target estimation of heart and respiration rates using ultra wideband sensors. Proceedings of the 2006 14th European Signal Processing Conference, Florence, Italy."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1073","DOI":"10.1109\/TMTT.2007.895653","article-title":"Arctangent demodulation with DC offset compensation in quadrature Doppler radar receiver systems","volume":"55","author":"Park","year":"2007","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_23","unstructured":"Li, C., and Lin, J. (2008, January 13\u201319). Complex signal demodulation and random body movement cancellation techniques for non-contact vital sign detection. Proceedings of the 2008 IEEE MTT-S International Microwave Symposium Digest, Atlanta, GA, USA."},{"key":"ref_24","unstructured":"Zhao, X., Song, C., Lubecke, V., and Boric-Lubecke, O. (September, January 30). DC coupled Doppler radar physiological monitor. Proceedings of the 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Boston, MA, USA."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"344","DOI":"10.1049\/el.2012.0071","article-title":"DC coupled CW radar sensor using fine-tuning adaptive feedback loop","volume":"48","author":"Gu","year":"2012","journal-title":"Electron. Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1109\/10.817625","article-title":"Microwave life-detection systems for searching human subjects under earthquake rubble or behind barrier","volume":"47","author":"Chen","year":"2000","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_27","unstructured":"Droitcour, A.D., Boric-Lubecke, O., Lubecke, V.M., and Lin, J. (2002, January 7). 0.25\/spl mu\/m CMOS and BiCMOS single-chip direct-conversion Doppler radars for remote sensing of vital signs. Proceedings of the 2002 IEEE International Solid-State Circuits Conference. Digest of Technical Papers (Cat. No. 02CH37315), San Francisco, CA, USA."},{"key":"ref_28","unstructured":"Lubecke, V., Boric-Lubecke, O., and Beck, E. (2002, January 2\u20137). A compact low-cost add-on module for Doppler radar sensing of vital signs using a wireless communications terminal. Proceedings of the 2002 IEEE MTT-S International Microwave Symposium Digest (Cat. No. 02CH37278), Seattle, WA, USA."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1109\/MEMB.2002.1044188","article-title":"A digital signal processor for Doppler radar sensing of vital signs","volume":"21","author":"Lohman","year":"2002","journal-title":"IEEE Eng. Med. Biol. Mag."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4464","DOI":"10.1109\/TMTT.2006.884652","article-title":"Experiment and spectral analysis of a low-power Ka-band heartbeat detector measuring from four sides of a human body","volume":"54","author":"Li","year":"2006","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Kazemi, S., Ghorbani, A., Amindavar, H., and Li, C. (2013). Cyclostationary Approach for Heart and Respiration Rates Monitoring with Body Movement Cancellation Using Radar Doppler System. arXiv.","DOI":"10.1016\/j.bspc.2014.03.012"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"568","DOI":"10.1109\/TMTT.2017.2730182","article-title":"Wavelet-transform-based data-length-variation technique for fast heart rate detection using 5.8-GHz CW Doppler radar","volume":"66","author":"Li","year":"2017","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"725","DOI":"10.1109\/TBME.2013.2288319","article-title":"Noncontact accurate measurement of cardiopulmonary activity using a compact quadrature Doppler radar sensor","volume":"61","author":"Hu","year":"2013","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Hu, X., and Jin, T. (2016). Short-range vital signs sensing based on EEMD and CWT using IR-UWB radar. Sensors, 16.","DOI":"10.20944\/preprints201608.0206.v3"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"783","DOI":"10.1109\/JSTARS.2013.2259801","article-title":"Advanced signal processing for vital sign extraction with applications in UWB radar detection of trapped victims in complex environments","volume":"7","author":"Li","year":"2013","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote. Sens."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"H\u00f8st-Madsen, A., Petrochilos, N., Boric-Lubecke, O., Lubecke, V.M., Park, B.K., and Zhou, Q. (2008). Signal processing methods for Doppler radar heart rate monitoring. Signal Processing Techniques for Knowledge Extraction and Information Fusion, Springer.","DOI":"10.1007\/978-0-387-74367-7_7"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1049\/iet-rsn.2014.0165","article-title":"Cyclostationary modelling of amplitude and frequency modulated signals in heart and respiration monitoring Doppler radar systems","volume":"9","author":"Kazemi","year":"2015","journal-title":"IET Radar Sonar Navig."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Yu, Z., Zhao, D., and Zhang, Z. (2018). Doppler radar vital signs detection method based on higher order cyclostationary. Sensors, 18.","DOI":"10.3390\/s18010047"},{"key":"ref_39","unstructured":"Roberts, J.R., and Hedges, J.R. (2004). Vital signs and patient monitoring techniques. Clinical Procedures in Emergency Medicine, Saunders. [4th ed.]."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1016\/j.sigpro.2015.09.011","article-title":"Cyclostationarity: New trends and applications","volume":"120","author":"Napolitano","year":"2016","journal-title":"Signal Process."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"639","DOI":"10.1016\/j.sigpro.2005.06.016","article-title":"Cyclostationarity: Half a century of research","volume":"86","author":"Gardner","year":"2006","journal-title":"Signal Process."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2355","DOI":"10.1109\/78.317857","article-title":"Statistical tests for presence of cyclostationarity","volume":"42","author":"Dandawate","year":"1994","journal-title":"IEEE Trans. Signal Process."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Zerhouni, K., Elbahhar, F., Elassali, R., and Elbaamrani, K. (2019, January 9\u201312). Blind parameters estimation for Universal Filtered Multicarrier: A cyclostationarity approach. Proceedings of the 2019 Wireless Telecommunications Symposium (WTS), New York, NY, USA.","DOI":"10.1109\/WTS.2019.8715533"},{"key":"ref_44","unstructured":"(2020, January 27). Federal Communications Commission FCC 13-39, Available online: https:\/\/www.fcc.gov\/engineering-technology\/electromagnetic-compatibility-division\/radio-frequency-safety\/faq\/rf-safety."},{"key":"ref_45","unstructured":"(2020, January 27). MySignals SW eHealth and Medical IoT Development Platform Technical Guide. Available online: https:\/\/www.the-iot-marketplace.com\/mysignals-sw-ehealth-medical-biometric-complete-kit-ble."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/12\/3396\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:39:33Z","timestamp":1760175573000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/12\/3396"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,6,16]]},"references-count":45,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2020,6]]}},"alternative-id":["s20123396"],"URL":"https:\/\/doi.org\/10.3390\/s20123396","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,6,16]]}}}