Calibration-Free Positioning Technique Using Wi-Fi Ranging and Built-In Sensors of Mobile Devices

As positioning solutions integrate multiple components to improve accuracy, the number of parameters that require calibration has increased. This article studies a calibration-free technique using Wi-Fi ranging and pedestrian dead reckoning (PDR), where every parameter in system is optimized real time. significantly decreases time effort required perform manual procedures enables solution achieve robust performance various situations. Additionally, this an efficient way performing irregular battery life network mobile devices. The proposed method was verified real-time Android application on several devices under large indoor office environment. Without any calibration, achieved up 1.38-m average accuracy for received signal strength (RSS)-based scenarios, which differs only by 30 cm from benchmark assuming perfect calibration. In addition, 1.04-m round trip (RTT)-based scenarios with 40-MHz bandwidth configuration, 10 benchmark.