Acoustic Localization System based on Smartphone without Time Synchronization

Aiming at the problems of traditional indoor localization system, such as special user equipment, strict clock synchronization and long localization period, we propose a smartphone indoor acoustic localization system without synchronization. The system uses acoustic signal collected by master node to calculate the real time difference among nodes, in that way it only needs to control the time order of acoustic signal for each node without strict clock synchronization. In addition, considering of limited bandwidth, the acoustic signal transmission scheme based on time division and frequency division is adopted to greatly reduce the localization period. Finally, users only need to hold a smartphone and the recorded data does not need to be uploaded to the server, which ensures the privacy security. Experiments demonstrated that the proposed system can achieve localization accuracy within 10cm in a 6×6m conference room with a 90% probability, which has certain application value and research significance.