TOA Estimation Method in Frequency Domain for Acoustic Ranging of WSN Node
Meng Ling-jun①②; Wang Hong-tao③; Xia Shan-hong①
①State Key Lab of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China; ②Graduate School of the Chinese Academy of Sciences, Beijing 100039, China; ③National Key Laboratory For Electronic Measurement Technolog (North University of China), Taiyuan 030051, China
Abstract：A new method of TOA (time of arrival) estimation in frequency domain used for wireless sensor nodes’ acoustic ranging is proposed in this paper. It shows higher accurate results under lower signal-noise-ratio applications compare to the time-domain method such as amplitude detection. It is based on Goertzel algorithm for short time frequency analyses. Fixed point algorithm is achieved by adjusting acoustic ranging signal’s frequency and window length. The computation of the algorithm can be done during one sampling period of microcontroller. A multi-magnitude threshold TOA estimate method is also studied for reducing the errors further. The algorithm has been tested on a node with a dsPIC6014A microprocessor. Experimental results show that the performance is better than those in time-domain. The acoustic ranging error is less than 3% at the distance of 25 meters.
2010, Vol. 32 
