Enhancing Wi-Fi Based Ranging Accuracy through a Two-stage Algorithmic Approach

In the current digital age, there has been a marked increase in the demand for indoor positioning systems (IPS). Driven by sectors like business, security, and entertainment, the requirement for indoor location data has become fundamental. While multiple IPS techniques exist, each with its merits and drawbacks, Wi-Fi-based positioning remains prominent due to its extensive infrastructure and cost-effectiveness. However, its precision has been a limiting factor for its large-scale adoption. This paper presents an innovative high-precision Wi-Fi-based ranging method, grounded in WLAN technology, offering an alternative for traditional ranging. By leveraging a two-stage algorithm, this method initially uses metrics such as RSSI or Time of Flight for an approximate range estimation, and the further refinement through a wave number disparity evaluation between transmitted single-tone signals of different frequencies. By selecting appropriate frequencies and convergence errors, this algorithm can enhance the positioning accuracy based on WLAN technology from meter-level to centimeter-level, or even millimeter-level. This approach promises enhanced accuracy, bridging the gap in the current Wi-Fi positioning methodologies, potentially reshaping the indoor positioning landscape.