Multi-dimensional parameter estimation and three-dimensional trajectory tracking algorithm based on WiFi signal

Location-based services can be used to a great effect in city planning and the development of the future IoT cities.Device-free passive indoor localization is playing a critical role in many applications such as tracking, elderly care, gesture recognition, etc. However, existed device-free localization systems either suffer from offline training to establish corresponding feature library or require dedicated special-purpose devices. Otherwise, most of the existing positioning systems was based on the positioning of the motion on the two-dimensional plane, no consideration had been given to tracking people who was walking in three-dimensional. To this end, we proposed a system based on commercial WiFi router and wireless network card to track people who was walking in three-dimensional. Firstly, we processed the wireless signal reflected back by human body to figure out the multiple signal parameters including Angle-of-Arrival, Time-of-Flight, and Doppler shifts together. Secondly we devised an algorithm to tracking the pedestrian 3d trajectory used the multiple parameters. Our system only used two link, can adapt to the environment dynamically, extracted the multi-dimensional parameters to tracking three-dimensional trajectory, and was able to achieve a accuracy below 0.7m when the human is walking in three-dimensional.