Locating Your Smart Devices with a Single Speaker

The ability of smart devices to determine their locations is the basis for many applications. We present LEAD, a system which can simultaneously Locate Everyday smArt Devices, such as smartphone, smartwatch, and headphone, with only one speaker. The principle of LEAD is leveraging the reflected path (e.g., by the wall) for single speaker based localization. Previous works cannot simultaneously locate multiple devices with unknown orientations. To overcome the challenges, we estimate the direction difference and distance difference between the LoS and Echo paths and combine them to derive the device location. Given limited sound bandwidth, we develop a high-resolution method to estimate the distance difference. To address the sparsity of microphones with large inter-distance, we generate virtual microphones on smart devices to estimate the direction difference. We reduce the computation overhead by searching the decomposed space for distance and direction. We extensively evaluate LEAD's performance in different scenarios. The results show a median relative distance error of 2.0 cm, relative direction error of 0.7°, and localization error of 0.29 m across various settings.