Simultaneous measurement of times-of-flight and communications in acoustic sensor networks

This article presents a process for the simultaneous determination of distances among objects in an indoor localization system using an acoustic sensor network. The proposed technique is based on a simultaneous time-of-flight measurement for the emitted acoustic signals from every object, without needing any additional signal to be used for synchronization. This is possible thanks to the properties of the used emission codification, which consists of complementary sets of sequences. According to the requirements of the positioning algorithm, a communication protocol is designed in order to transmit the collected information among nodes, so, locally, the distances and positions can be computed at each node.