Device-Free Vehicle Speed Estimation With WiFi

• Published in: IEEE transactions on vehicular technology 2018-09, Vol.67 (9), p.8205-8214
• Main Authors: Wang, Jie, Tong, Jingyu, Gao, Qinghua, Wu, Zhenyu, Bi, Sheng, Wang, Hongyu
• Format: Article
• Language: English
• Subjects: Detection; Device-free; Estimation; Monitoring; Sensors; speed estimation; Vehicle dynamics; WiFi; Wireless communication; Wireless communications; Wireless fidelity; wireless sensing; Wireless sensor networks
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2018.2840052

Vehicle networks is a promising technique, which could provide ubiquitous wireless access for vehicles and realize intelligent transportation. Motivated by the recent advances on device-free wireless sensing, this paper explores a novel technique, which could estimate the speed of a vehicle by analyzing its influence on surrounding wireless signals from roadside wireless infrastructures, such as WiFi. This technique could enable vehicle networks with new moving speed sensing ability and evolve it into a large-scale sensing network, which could monitor the traffic status seamlessly. To achieve this goal, in this paper, we propose and formulate a model to characterize the relationship between the phase and amplitude measurements and the vehicle speed. Based on the model, we develop an efficient method to detect the vehicle and estimate its speed accordingly using the frequency-domain information involved in the spectrogram. We carry out extensive experiments utilizing commodity WiFi. The experimental results reveal that the proposed method could estimate the speed with an error of less than 2.6 km/h, which meets the United Nations regulation for speedometer.