Performance Analysis of Active Target Localization Using TDOA and FDOA Measurements in WSN

Target localization is one of the basic functions of wireless sensor networks. In the target localization algorithms, the problem of how many sensors are needed and how they are deployed is what we are concerned about in this paper. The authors of (K.C. Ho et al., 2007) present the mathematical expression of Cramer-Rao lower bound for the localization error, which is the smallest lower bound of any unbiased estimation. However it is difficult to be used to find out the relation between sensor number and Cramer-Rao lower bound directly. In this paper the relation between sensor number and Cramer- Rao lower bound is revealed by simulation. And how the topology affects the Cramer-Rao lower bound is also presented.