WiVir: Exploiting WiFi-based Virtual Antenna Array for Passive Stationary Human Localization

WiFi passive positioning enables precise target tracking without additional devices, offering a cost-effective solution for elder care, security, and smart homes. However, it faces challenges such as distinguishing stationary humans from static objects and limited angular resolution due to existing hardware constraints. In this paper, we present WiVir, a virtual antenna array system based on commodity WiFi device for passive localization of stationary humans. The system addresses the challenges of channel state information (CSI) measurement errors and innovatively applies the concept of virtual antenna array (VAA) in WiFi-MIMO modes. It overcomes the limitation of the number of antennas in commercial WiFi Network Interface Controller (NIC) and significantly reduces the beam width of beamforming. Beamforming is used to obtain the angle of arrival (AOA), and the beam is analyzed in the frequency domain to generate a two-dimensional angular frequency image. Experimental results show that WiVir achieves 98.4% accuracy and strong robustness in indoor environments, providing precise positioning within a certain angle range.