Bias analysis of source localization using the maximum likelihood estimator

The nonlinear nature of the source localization problem creates bias to a location estimate. The bias could play a significant role in limiting the performance of localization and tracking when multiple measurements at different instants are available. This paper performs bias analysis of the source location estimate obtained by the maximum likelihood estimator, where the positioning measurements can be TOA, TDOA, or AOA. The effect of bias to the mean-square localization error is examined and the amounts of bias introduced by the three types of measurements are contrasted.