{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,9]],"date-time":"2026-06-09T15:39:31Z","timestamp":1781019571789,"version":"3.54.1"},"reference-count":17,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2019,7,12]],"date-time":"2019-07-12T00:00:00Z","timestamp":1562889600000},"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 wireless sensing approaches have emerged in recent years, in order to enable novel enhanced developments in the framework of healthcare and biomedical scenarios. One of these technologically advanced solutions is given by software-defined radar platforms, a low-cost radar implementation, where all operations are implemented and easily changed via software. In the present paper, a software-defined radar implementation with Doppler elaboration features is presented, to be applied for the non-contact monitoring of human respiration signals. A quadrature receiver I\/Q (In-phase\/Quadrature) architecture is adopted in order to overcome the critical issues related to the occurrences of null detection points, while the phase-locked loop components included in the software defined radio transceiver are successfully exploited to guarantee the phase correlation between I\/Q signal components. The proposed approach leads to a compact, low-cost, and flexible radar solution, whose application abilities may be simply changed via software, with no need for hardware modifications. Experimental results on a human target are discussed so as to demonstrate the feasibility of the proposed approach for vital signs detection.<\/jats:p>","DOI":"10.3390\/s19143085","type":"journal-article","created":{"date-parts":[[2019,7,12]],"date-time":"2019-07-12T11:49:38Z","timestamp":1562932178000},"page":"3085","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":33,"title":["Software-Defined Doppler Radar Sensor for Human Breathing Detection"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8028-2268","authenticated-orcid":false,"given":"Sandra","family":"Costanzo","sequence":"first","affiliation":[{"name":"DIMES, Universit\u00e0 della Calabria, 87036 Rende, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,7,12]]},"reference":[{"key":"ref_1","first-page":"165","article-title":"Overview of recent development on wireless sensing circuits and sysyems for healthcare and biomedical applications","volume":"8","author":"Li","year":"2018","journal-title":"IEEE J. Sel. Topics Circ. Syst."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1530","DOI":"10.1109\/PROC.1975.9992","article-title":"Non-invasive microwave measurement of respiration","volume":"63","author":"Lin","year":"1975","journal-title":"Proc. IEEE"},{"key":"ref_3","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."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"6383","DOI":"10.3390\/s150306383","article-title":"Assessment of Human Respiration Patterns via Noncontact Sensing Using Doppler Multi-Radar System","volume":"15","author":"Gu","year":"2015","journal-title":"Sensors"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2046","DOI":"10.1109\/TMTT.2013.2256924","article-title":"A Review on Recent Advances in Doppler Radar Sensors for Noncontact Healthcare Monitoring","volume":"61","author":"Li","year":"2013","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"838","DOI":"10.1109\/TMTT.2004.823552","article-title":"Range Correlation and I\/Q Performance Benefits in Single-Chip Silicon Doppler Radars for Noncontact Cardiopulmonary Monitoring","volume":"52","author":"Droitcour","year":"2004","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_7","first-page":"7","article-title":"High resolution software defined radar system for target detection","volume":"2013","author":"Costanzo","year":"2013","journal-title":"J. Electr. Comput. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"417","DOI":"10.2528\/PIERB13052904","article-title":"Potentialities of USRP-based software defined radar systems","volume":"53","author":"Costanzo","year":"2013","journal-title":"Prog. Electromagn. Res. B"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Costanzo, S., Spadafora, F., Moreno, H.O., Scarcella, F., and di Massa, G. (2013). Multiband software defined radar for soil discontinuities detection. J. Electr. Comput. Eng., 2013.","DOI":"10.1155\/2013\/379832"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1007\/978-3-319-31307-8_34","article-title":"Software-defined radar system for landslides monitoring","volume":"445","author":"Costanzo","year":"2016","journal-title":"Adv. Intell. Syst. Comput."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Raffo, A., Costanzo, S., and di Massa, G. (2017). Software defined Doppler radar as a contactless multipurpose microwave sensor for vibrations monitoring. Sensors, 17.","DOI":"10.3390\/s17010115"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1022","DOI":"10.1007\/978-3-319-56538-5_103","article-title":"Doppler elaboration for vibrations detection using software defined radar","volume":"570","author":"Raffo","year":"2017","journal-title":"Adv. Intell. Syst. Comput."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1038\/s41928-017-0001-0","article-title":"Monitoring vital signs over multiplexed radio by near-field coherent sensing","volume":"1","author":"Hui","year":"2018","journal-title":"Nat. Electron."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Li, W., Tan, B., and Piechocki, R.J. (2016, January 22\u201327). Non-contact breathing detection using passive radar. Proceedings of the 2016 IEEE International Conference on Communications (ICC), Kuala Lumpur, Malaysia.","DOI":"10.1109\/ICC.2016.7511389"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1471","DOI":"10.1007\/978-3-319-77712-2_142","article-title":"Quadrature receiver benefits in CW Doppler radar sensors for vibrations detection","volume":"Volume 746","author":"Raffo","year":"2018","journal-title":"Advances in Intelligent Systems and Computing"},{"key":"ref_16","unstructured":"Raffo, A. (2018). Software-Defined Radar for Monitoring and Sensing Applications. [Ph.D. Thesis, University of Calabria-Advisor]."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Mostafanezhad, I., Boric-Lubecke, O., and Lubecke, V. (2010, January 10\u201314). A Coherent Low IF Receiver Architecture for Doppler Radar Motion Detector Used in Life Signs Monitoring. In Proceedings of the 2010 IEEE Radio and Wireless Symposium (RWS), New Orleans, LA, USA.","DOI":"10.1109\/RWS.2010.5434190"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/14\/3085\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:05:09Z","timestamp":1760187909000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/14\/3085"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,7,12]]},"references-count":17,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2019,7]]}},"alternative-id":["s19143085"],"URL":"https:\/\/doi.org\/10.3390\/s19143085","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,7,12]]}}}