EURASIP Journal on Advances in Signal Processing
Volume 2008 (2008), Article ID 236791, 17 pages
doi:10.1155/2008/236791
Abstract
The theoretical and practical performance limits of a 2D ultrawideband impulse-radio
localization system operating in the far field are studied under the assumption that estimates of
location are based on time-difference-of-arrival (TDOA) measurements. Performance is
evaluated in the presence of errors in both the TDOA measurements and the sensor locations.
The performance of both optimal (maximum-likelihood) and suboptimal location estimation
algorithms is studied and compared with the theoretical performance limit defined by the
Cramér-Rao lower bound on the variance of unbiased TDOA location estimates. A novel
weighted total-least-squares algorithm is introduced that compensates somewhat for errors in
sensor positions and reduces the bias in location estimation compared with a widely used
weighted least-squares approach. In addition, although target tracking per se is not considered in
this paper, performance is evaluated both under the assumption that sequential location estimates
are not aggregated as well as under the assumption that some sort of tracker is available to
aggregate a sequence of estimates.