TDOA Based Positioning in the Presence of Unknown Clock Skew
Journal article, 2013

This paper studies the positioning problem of a single target node based on time-difference-of-arrival (TDOA) measurements in the presence of clock imperfections. Employing an affine model for the behaviour of a local clock, it is observed that TDOA based approaches suffer from a parameter of the model, called the clock skew. Modeling the clock skew as a nuisance parameter, this paper investigates joint clock skew and position estimation. The maximum likelihood estimator (MLE) is derived for this problem, which is highly nonconvex and difficult to solve. To avoid the difficulty in solving the MLE, we employ suitable approximations and relaxations and propose two suboptimal estimators based on semidefinite programming and linear estimation. To further improve the estimation accuracy, we also propose a refining step. In addition, the Cramér-Rao lower bound (CRLB) is derived for this problem as a benchmark. Simulation results show that the proposed suboptimal estimators can attain the CRLB for sufficiently high signal-to-noise ratios.

Cramer-Rao lower bound (CRLB)

maximum likelihood estimator (MLE)

positioning

Wireless sensor network

linear estimator

clock skew

semidefinite programming

time-difference-of-arrival (TDOA)

clock synchronization

Author

Mohammad Reza Gholami

Chalmers, Signals and Systems, Communication and Antenna Systems, Communication Systems

Sinan Gezici

Erik Ström

Chalmers, Signals and Systems, Communication and Antenna Systems, Communication Systems

IEEE Transactions on Communications

0090-6778 (ISSN)

Vol. 61 6 2522 - 2534

Areas of Advance

Information and Communication Technology

Subject Categories

Signal Processing

DOI

10.1109/TCOMM.2013.032013.120381

More information

Created

10/6/2017