Improve the positioning accuracy for wireless sensor nodes based on TFDA and TFOA using data fusion

In wireless sensor networks (WSN), location information acquisition is critical to guarantee their performance. This paper presents the positioning methods in WSN with based on the linear frequency modulation continuous wave (FMCW) techniques. Reference nodes with known locations transmit linear FMCW reference signals, while other sensor nodes estimate their locations based on the time frequency difference arrival (TFDA) or time frequency of arrival (TFOA). The geometric locations of RNs affect the location accuracy. In order to overcome the geometric dilution of precision (GDOP) effect and improve the location accuracy, the data fusion method is proposed. The location estimates from TFDA and TFOA are combined using Bayes rule. The simulation results show that the data fusion method enjoys higher location accuracy.