Relative location estimation in wireless sensor networks

N. Patwari, A.O. Hero, M. Perkins, N.S. Correal, R.J. O'Dea
2003 IEEE Transactions on Signal Processing  
This article explores self-configuration in wireless sensor networks. Self-configuration is a general class of estimation problems which we explore via the Cramér-Rao bound (CRB). Specifically, the sensor location estimation problem is explored for sensors that measure range via received signal strength (RSS) or time-of-arrival (TOA) between themselves and neighboring sensors. A small fraction of sensors in the network have known location while the remaining locations must be estimated. We
more » ... e CRBs and maximum-likelihood estimators (MLEs) for sensor location estimation under a Gaussian and log-normal model for the TOA and RSS measurements, respectively. The variance bounds are calculated for example networks of devices. Then we report on an extensive TOA and RSS measurement campaign in an indoor office area which shows MLE performance in a real channel. Finally, relative location estimation algorithms are implemented in a wireless sensor network testbed. The wireless sensor devices are deployed in indoor and outdoor environments to demonstrate the accuracy and real-time operation of the location system. Results from the measurements and testbed experiments demonstrate 1 m RMS location errors using TOA, and 1 m to 2 m RMS location errors using RSS.
doi:10.1109/tsp.2003.814469 fatcat:ge34lhwapfa5xi75lucyw2nt3y