{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T21:46:45Z","timestamp":1790286405008,"version":"4.1.0"},"reference-count":46,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,12,31]],"date-time":"2020-12-31T00:00:00Z","timestamp":1609372800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China under Grant","award":["51774282"],"award-info":[{"award-number":["51774282"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper, we propose a novel gesture recognition system based on a smartphone. Due to the limitation of Channel State Information (CSI) extraction equipment, existing WiFi-based gesture recognition is limited to the microcomputer terminal equipped with Intel 5300 or Atheros 9580 network cards. Therefore, accurate gesture recognition can only be performed in an area relatively fixed to the transceiver link. The new gesture recognition system proposed by us breaks this limitation. First, we use nexmon firmware to obtain 256 CSI subcarriers from the bottom layer of the smartphone in IEEE 802.11ac mode on 80 MHz bandwidth to realize the gesture recognition system\u2019s mobility. Second, we adopt the cross-correlation method to integrate the extracted CSI features in the time and frequency domain to reduce the influence of changes in the smartphone location. Third, we use a new improved DTW algorithm to classify and recognize gestures. We implemented vast experiments to verify the system\u2019s recognition accuracy at different distances in different directions and environments. The results show that the system can effectively improve the recognition accuracy.<\/jats:p>","DOI":"10.3390\/s21010222","type":"journal-article","created":{"date-parts":[[2020,12,31]],"date-time":"2020-12-31T14:31:49Z","timestamp":1609425109000},"page":"222","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["A Novel Gesture Recognition System Based on CSI Extracted from a Smartphone with Nexmon Firmware"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6186-0117","authenticated-orcid":false,"given":"Tao","family":"Li","sequence":"first","affiliation":[{"name":"School of Computer Science and Technology, China University of Mining and Technology, Xuzhou 221116, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5589-1582","authenticated-orcid":false,"given":"Chenqi","family":"Shi","sequence":"additional","affiliation":[{"name":"School of Computer Science and Technology, China University of Mining and Technology, Xuzhou 221116, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peihao","family":"Li","sequence":"additional","affiliation":[{"name":"School of Computer Science and Technology, China University of Mining and Technology, Xuzhou 221116, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pengpeng","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Computer Science and Technology, China University of Mining and Technology, Xuzhou 221116, China"},{"name":"China Mine Digitization Engineering Research Center, Ministry of Education, Xuzhou 221116, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Gkioxari, G., Girshick, R., Doll\u00e1r, P., and He, K. (2018, January 18\u201323). Detecting and recognizing human-object interactions. Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, Salt Lake City, UT, USA.","DOI":"10.1109\/CVPR.2018.00872"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Li, T., Liu, Q., and Zhou, X. (2016, January 26\u201330). Practical human sensing in the light. Proceedings of the 14th Annual International Conference on Mobile Systems, Applications, and Services, Singapore.","DOI":"10.1145\/2906388.2906401"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Wang, M., Ni, B., and Yang, X. (2017, January 21\u201326). Recurrent modeling of interaction context for collective activity recognition. Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, Honolulu, HI, USA.","DOI":"10.1109\/CVPR.2017.783"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1145\/2499621","article-title":"A tutorial on human activity recognition using body-worn inertial sensors","volume":"46","author":"Bulling","year":"2014","journal-title":"ACM Comput. Surv. (CSUR)"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1145\/3090076","article-title":"Ensembles of deep lstm learners for activity recognition using wearables","volume":"1","author":"Guan","year":"2017","journal-title":"Proc. ACM Interact. Mob. Wearable Ubiquitous Technol."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Shen, S., Wang, H., and Roy Choudhury, R. (2016, January 26\u201330). I am a smartwatch and i can track my user\u2019s arm. Proceedings of the 14th Annual International Conference on Mobile Systems, Applications, and Services, Singapore.","DOI":"10.1145\/2906388.2906407"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Sun, L., Sen, S., Koutsonikolas, D., and Kim, K.H. (2015, January 7\u201311). Widraw: Enabling hands-free drawing in the air on commodity wifi devices. Proceedings of the 21st Annual International Conference on Mobile Computing and Networking, Paris, France.","DOI":"10.1145\/2789168.2790129"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Virmani, A., and Shahzad, M. (2017, January 19\u201323). Position and orientation agnostic gesture recognition using wifi. Proceedings of the 15th Annual International Conference on Mobile Systems, Applications, and Services, Niagara Falls, NY, USA.","DOI":"10.1145\/3081333.3081340"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Tan, S., and Yang, J. (2016, January 5\u20138). WiFinger: Leveraging commodity WiFi for fine-grained finger gesture recognition. Proceedings of the 17th ACM International Symposium on Mobile Ad Hoc Networking And Computing, Paderborn, Germany.","DOI":"10.1145\/2942358.2942393"},{"key":"ref_10","first-page":"1","article-title":"QGesture: Quantifying gesture distance and direction with WiFi signals","volume":"2","author":"Yu","year":"2018","journal-title":"Proc. ACM Interact. Mob. Wearable Ubiquitous Technol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Venkatnarayan, R.H., Page, G., and Shahzad, M. (2018, January 10\u201315). Multi-user gesture recognition using WiFi. Proceedings of the 16th Annual International Conference on Mobile Systems, Applications, and Services, Munich, Germany.","DOI":"10.1145\/3210240.3210335"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1145\/3264944","article-title":"Augmenting user identification with WiFi based gesture recognition","volume":"2","author":"Shahzad","year":"2018","journal-title":"Proc. ACM Interact. Mob. Wearable Ubiquitous Technol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Ali, K., Liu, A.X., Wang, W., and Shahzad, M. (2015, January 7\u201311). Keystroke recognition using wifi signals. Proceedings of the 21st Annual International Conference on Mobile Computing and Networking, Paris, France.","DOI":"10.1145\/2789168.2790109"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1145\/1925861.1925870","article-title":"Tool release: Gathering 802.11 n traces with channel state information","volume":"41","author":"Halperin","year":"2011","journal-title":"ACM Sigcomm Comput. Commun. Rev."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1342","DOI":"10.1109\/TMC.2018.2860991","article-title":"Precise power delay profiling with commodity Wi-Fi","volume":"18","author":"Xie","year":"2018","journal-title":"IEEE Trans. Mob. Comput."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Abdelnasser, H., Youssef, M., and Harras, K.A. (May, January 26). Wigest: A ubiquitous wifi-based gesture recognition system. Proceedings of the 2015 IEEE Conference on Computer Communications (INFOCOM), Hong Kong, China.","DOI":"10.1109\/INFOCOM.2015.7218525"},{"key":"ref_17","unstructured":"Zhang, J., Tang, Z., Li, M., Fang, D., Nurmi, P., and Wang, Z. (November, January 29). CrossSense: Towards cross-site and large-scale WiFi sensing. Proceedings of the 24th Annual International Conference on Mobile Computing and Networking, New Delhi, India."},{"key":"ref_18","unstructured":"Jiang, W., Miao, C., Ma, F., Yao, S., Wang, Y., Yuan, Y., Xue, H., Song, C., Ma, X., and Koutsonikolas, D. (November, January 29). Towards environment independent device free human activity recognition. Proceedings of the 24th Annual International Conference on Mobile Computing and Networking, New Delhi, India."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Zheng, Y., Zhang, Y., Qian, K., Zhang, G., Liu, Y., Wu, C., and Yang, Z. (2019, January 17\u201321). Zero-effort cross-domain gesture recognition with Wi-Fi. Proceedings of the 17th Annual International Conference on Mobile Systems, Applications, and Services, Seoul, Korea.","DOI":"10.1145\/3307334.3326081"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Schulz, M., Link, J., Gringoli, F., and Hollick, M. (2018, January 10\u201315). Shadow Wi-Fi: Teaching smartphones to transmit raw signals and to extract channel state information to implement practical covert channels over Wi-Fi. Proceedings of the 16th Annual International Conference on Mobile Systems, Applications, and Services, Munich, Germany.","DOI":"10.1145\/3210240.3210333"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Gringoli, F., Schulz, M., Link, J., and Hollick, M. (2019, January 25). Free Your CSI: A Channel State Information Extraction Platform For Modern Wi-Fi Chipsets. Proceedings of the 13th International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization, Los Cabos, Mexico.","DOI":"10.1145\/3349623.3355477"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Han, C., Wu, K., Wang, Y., and Ni, L.M. (May, January 27). WiFall: Device-Free Fall Detection by Wireless Networks. Proceedings of the IEEE INFOCOM 2014\u2014IEEE Conference on Computer Communications, Toronto, ON, Canada.","DOI":"10.1109\/INFOCOM.2014.6847948"},{"key":"ref_23","unstructured":"Yan, W., Jian, L., Chen, Y., Gruteser, M., and Liu, H. (2014, January 7\u201310). E-eyes: Device-free location-oriented activity identification using fine-grained WiFi signatures. Proceedings of the 20th Annual International Conference on Mobile Computing and Networking, Maui, HI, USA."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Fang, B., Lane, N.D., Zhang, M., and Kawsar, F. (2016, January 11\u201314). HeadScan: A Wearable System for Radio-Based Sensing of Head and Mouth-Related Activities. Proceedings of the IEEE 2016 15th ACM\/IEEE International Conference on Information Processing in Sensor Networks (IPSN), Vienna, Austria.","DOI":"10.1109\/IPSN.2016.7460677"},{"key":"ref_25","unstructured":"Fang, B., Lane, N.D., Zhang, M., Boran, A., and Kawsar, F. (2016, January 25\u201330). BodyScan: Enabling Radio-based Sensing on Wearable Devices for Contactless Activity and Vital Sign Monitoring. Proceedings of the 14th Annual International Conference on Mobile Systems, Applications, and Services, Singapore."},{"key":"ref_26","first-page":"1","article-title":"IndoTrack: Device-free indoor human tracking with commodity Wi-Fi","volume":"1","author":"Li","year":"2017","journal-title":"Proc. ACM Interact. Mob. Wearable Ubiquitous Technol."},{"key":"ref_27","unstructured":"Qian, K., Wu, C., Yang, Z., Liu, Y., and Jamieson, K. (2017, January 10\u201314). Widar: Decimeter-level passive tracking via velocity monitoring with commodity Wi-Fi. Proceedings of the 18th ACM International Symposium on Mobile Ad Hoc Networking and Computing, Chennai, India."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1118","DOI":"10.1109\/JSAC.2017.2679658","article-title":"Device-free human activity recognition using commercial WiFi devices","volume":"35","author":"Wang","year":"2017","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1145\/2816795.2818072","article-title":"Capturing the human figure through a wall","volume":"34","author":"Adib","year":"2015","journal-title":"ACM Trans. Graph. (TOG)"},{"key":"ref_30","unstructured":"Adib, F., Kabelac, Z., and Katabi, D. (2015, January 4\u20136). Multi-person localization via RF body reflections. Proceedings of the 12th USENIX Symposium on Networked Systems Design and Implementation, Berkeley, CA, USA."},{"key":"ref_31","unstructured":"Adib, F., Kabelac, Z., Katabi, D., and Miller, R.C. (2015, January 4\u20136). 3D tracking via body radio reflections. Proceedings of the 12th USENIX Symposium on Networked Systems Design and Implementation, Oakland, CA, USA."},{"key":"ref_32","unstructured":"Joshi, K., Bharadia, D., Kotaru, M., and Katti, S. (2015, January 4\u20136). WiDeo: Fine-grained Device-free Motion Tracing using {RF} Backscatter. Proceedings of the 12th USENIX Conference on Networked Systems Design and Implementation, Oakland, CA, USA."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Adib, F., and Katabi, D. (2013, January 12\u201316). See through walls with WiFi!. Proceedings of the ACM SIGCOMM 2013 Conference on SIGCOMM, Hong Kong, China.","DOI":"10.1145\/2486001.2486039"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Li, X., Li, S., Zhang, D., Xiong, J., Wang, Y., and Mei, H. (2016, January 12\u201316). Dynamic-music: Accurate device-free indoor localization. Proceedings of the 2016 ACM International Joint Conference on Pervasive and Ubiquitous Computing, Heidelberg, Germany.","DOI":"10.1145\/2971648.2971665"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1787","DOI":"10.1109\/TMC.2013.92","article-title":"Multiple target tracking with RF sensor networks","volume":"13","author":"Bocca","year":"2013","journal-title":"IEEE Trans. Mob. Comput."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Wang, J., Jiang, H., Xiong, J., Jamieson, K., Chen, X., Fang, D., and Xie, B. (2016, January 3\u20137). LiFS: Low human-effort, device-free localization with fine-grained subcarrier information. Proceedings of the 22nd Annual International Conference on Mobile Computing and Networking, New York, NY, USA.","DOI":"10.1145\/2973750.2973776"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Chen, T.H., Sou, S.I., and Lee, Y. (2019, January 5\u20138). WiTrack: Human-to-Human Mobility Relationship Tracking in Indoor Environments Based on Spatio-Temporal Wireless Signal Strength. Proceedings of the 17th IEEE International Conference on Dependable, Autonomic and Secure Computing (DASC 2019), Fukuoka, Japan.","DOI":"10.1109\/DASC\/PiCom\/CBDCom\/CyberSciTech.2019.00146"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Zhao, M., Adib, F., and Katabi, D. (2016, January 3\u20137). Emotion recognition using wireless signals. Proceedings of the 22nd Annual International Conference on Mobile Computing and Networking, New York, NY, USA.","DOI":"10.1145\/2973750.2973762"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Liu, X., Cao, J., Tang, S., and Wen, J. (2014, January 2\u20135). Wi-Sleep: Contactless sleep monitoring via WiFi signals. Proceedings of the 2014 IEEE Real-Time Systems Symposium, Rome, Italy.","DOI":"10.1109\/RTSS.2014.30"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Abdelnasser, H., Harras, K.A., and Youssef, M. (2015, January 22\u201325). UbiBreathe: A ubiquitous non-invasive WiFi-based breathing estimator. Proceedings of the 16th ACM International Symposium on Mobile Ad Hoc Networking and Computing, Hangzhou, China.","DOI":"10.1145\/2746285.2755969"},{"key":"ref_41","unstructured":"Zhao, M., Yue, S., Katabi, D., Jaakkola, T.S., and Bianchi, M.T. (2017, January 6\u201311). Learning sleep stages from radio signals: A conditional adversarial architecture. Proceedings of the International Conference on Machine Learning, Sydney, Australia."},{"key":"ref_42","unstructured":"Pu, Q., Gupta, S., Gollakota, S., and Patel, S. (October, January 30). Whole-home gesture recognition using wireless signals. Proceedings of the 19th Annual International Conference on Mobile Computing & Networking, Miami, FL, USA."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Aumi, M.T.I., Gupta, S., Goel, M., Larson, E., and Patel, S. (2013, January 8\u201312). DopLink: Using the doppler effect for multi-device interaction. Proceedings of the 2013 ACM International Joint Conference on Pervasive and Ubiquitous Computing, Zurich, Switzerland.","DOI":"10.1145\/2493432.2493515"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1328","DOI":"10.1109\/TGRS.2009.2012849","article-title":"Human activity classification based on micro-Doppler signatures using a support vector machine","volume":"47","author":"Kim","year":"2009","journal-title":"IEEE Trans. Geosci. Remote. Sens."},{"key":"ref_45","first-page":"17","article-title":"Dynamic Gesture Identity Authentication of Smart Phone Based on CM-DTW Algorithms","volume":"28","author":"Li","year":"2019","journal-title":"Comput. Syst. Appl."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1109\/TASSP.1978.1163055","article-title":"Dynamic Programming Algorithm Optimization for Spoken Word Recognition","volume":"26","author":"Sakoe","year":"1978","journal-title":"IEEE Trans. Acoust. Speech Signal Process."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/1\/222\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:48:35Z","timestamp":1760179715000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/1\/222"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12,31]]},"references-count":46,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2021,1]]}},"alternative-id":["s21010222"],"URL":"https:\/\/doi.org\/10.3390\/s21010222","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,12,31]]}}}