TOF Estimation of Single Antenna for Commercial Wi-Fi

With the explosive growth of mobile devices, the need for precise positioning in indoor environments is becoming more prominent. Yet these state-of-the-art solutions require either multiple devices or multiple antennas that not available on all devices. The positioning of devices with simpler structures should be investigated. In this paper, we propose a method to treat channel state information (CSI) data as a random process, construct an autocorrelation matrix and apply the MUSIC algorithm to achieve the purpose of single antenna estimation of time of flight (TOF). We study the distribution of symbol time offset (STO) errors by means of statistical tests and provide a theoretical basis for real experiments. Finally, we use Intel5300 commercial wireless network card to conduct experiments in typical indoor environments of NLOS and LOS, and the median errors of 33m and 1.2m are achieved respectively.