Time Of Arrival Based Localization in Wireless Sensor Networks : A   Linear Approach
  In this paper, we aim to determine the location information of a node deployed in Wireless Sensor Networks (WSN). We estimate the position of an unknown source node using localization based on linear approach on a single simulation platform. The Cramer Rao Lower Bound (CRLB) for position estimate is derived first and the four linear approaches namely Linear Least Squares (LLS), Subspace Approach (SA), Weighted Linear Least Squares (WLLS) and Two-step WLS have been derived and presented. Based on the simulation study the results have been compared. The simulation results show that the Two- step WLS approach is having higher localization accuracy.   Keywords: Source Localization, Time of Arrival,Linear Least Squares, Subspace Approach, Weighted Linear Least Squares, Two-step WLS and CRLB. 
S Ravindra and S N Jagadeesha
cs.NI