基于WiFi信号的多维参数估计与三维轨迹跟踪算法

在未来物联城市的规划和现有的发展情况下，基于位置的服务变得越来越重要。室内定位在很多场景都有着明朗的应用前景，如轨迹跟踪、老人看护、手势识别等。但是现存的室内定位通常需要在离线阶段大量实验以建立相应特征库，有些系统还对设备有特殊要求。另外，现有的定位系统多是基于对二维平面上的运动进行定位，未曾考虑对进行三维运动的人进行定位。对此我们提出了一种基于商用WiFi路由器和无线网卡下的系统，对人体反射回的无线信号做处理，从而得到多普勒频移、信号飞行时间、到达角度这些多维参数，对进行三维运动的人进行跟踪定位。我们的系统只用两个接收端,可以动态的适应环境，提取出多维用以估计位置的参数，达到0.7m精度的三维轨迹跟踪。 

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.