Timing Over Wireless

Speaker: Satyam Dwivedi, KTH Royal Institute of Technology

Talk Title: Timing Over Wireless

Abstract: Traditionally wireless technology has been used to communicate messages. However, in this talk will focus on two other applications, namely, precise positioning in indoor environments, and clock parameter exchange of electronic nodes over wireless. Both these applications rely on measuring and estimating time related parameters over wireless.

Our work on indoor positioning is based on a new method of distributed positioning which exploits time delays in transmission scheduling. This method achieves distributed positioning, where every node in a network knows the position of every other node, without requiring any communication among nodes. The underlying idea can also be extended to self localize a passive network node. Via extensive experiments we verify that our method is a very efficient cooperative distributed position methodology that in surpasses the capabilities and performance of many alternative in the literature.

Precise wireless clock synchronization is the holy grail of achieving efficiency and coordination in wireless sensor networks. I will describe a new technique which provides range and clock parameter estimation simultaneously between any two node over wireless. In order to experimentally verify the algorithm, we developed a new in-house measurement model.

Accuracies obtained by our above models are in the order of sub-Hertz for clock frequency error estimation, and sub-nanosecond for clock phase error estimation, and less than 30 cm for range estimation over a range up to 10 meters.

Precisely estimating timing parameters over wireless results in hardware constraints. Continuous improvement in the hardware which can accomplish the tasks of positioning, clock synchronization and communication will be discussed, and our efforts towards developing an ultra-wideband (UWB) testbed will be explained.

Host: Andreas Molisch, molisch@usc.edu, EEB 530, x04670

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Gerrielyn Ramos