基于离开角的商用毫米波设备定位方法研究

AoD-based localization with cots millimeter-wave devices

近年来,基于无线射频信号的定位技术迅速发展.然而,已有基于商用Wi-Fi设备的定位系统在实用性和准确性上存在明显局限.新兴WiGig设备采用毫米波通信,天线数远多于Wi-Fi设备,具有更高的角度分辨率.然而受限于成本,商用WiGig设备采用模拟波束成型方法,无法获得各天线的信道响应.本文利用新兴毫米波设备,实现高精度定位系统WiGLoc.为此,首先对天线阵列接收信号强度建模(received signal strength,RSS),恢复天线的信道状态信息(channel state information,CSI);然后,对天线阵列进行校准,测量天线阵列参数;最后,利用天线信道状态信息和天线阵列布局信息估计发射端到目标的信号离开角(angle of departure,AoD),对目标定位.实验结果表明,WiGLoc平均三维追踪精度达到了6 cm,平均二维定位精度达到了27 cm.与此相比,已有基于波束成型的方法三维追踪和二维定位的精度分别仅为11 cm和44 cm.

Radio frequency-based localization techniques have undergone rapid development in recent years.However,existing localization systems on commercial Wi-Fi devices are either impractical or inaccurate.The newly emerging WiGig devices use millimeter-wave signals to communicate.As they have much more antennas than Wi-Fi devices,and they also have a higher angular resolution.However,because of cost limitations,commercial WiGig devices use analog beamforming,and the channel response of each antenna is unavailable.In this work,we propose WiGLoc,a system for WiGig devices that provides accurate localization.To achieve this goal,we model the RSS of the antenna array,from which the CSIs of individual antennas are recovered.Then,the antenna array is calibrated,and the array geometry is obtained.WiGLoc estimates AoDs from WiGig APs to the target with antenna CSIs and array geometry to localize the target.Experimental results show that the average 3 D tracking and 2 D localization errors of WiGLoc are only 6 and 27 cm,respectively;whereas those of the state-of-the-art beamforming approach are 11 and 44 cm,respectively.