Abstract
A modified round trip time (RTT) time of arrival (ToA) technique is present to measure the distance between two nodes in wireless sensor network. The ultra wide band spectrum and Gaussian monopulse shaping is used on MATLAB platform for simulations. The nodes are simulated under following environments of 802.15.4a channel model for distances measurement: residential, office, industrial, outdoor and open outdoor. The measured distances are analyzed and compared with set distances using calculated absolute error versus set distance graphs for different UWB frequencies, 802.15.4a channels and sampling frequencies. Finally, trilateration using singular value decomposition (SVD) method calculations are done for localization by using the measured distances. The position errors with respect to set positions are calculated for different trilateration layouts.