@misc{10481/64140,
year = {2013},
month = {3},
url = {http://hdl.handle.net/10481/64140},
abstract = {This paper describes the TELIAMADE system, a new indoor positioning system
based on time-of-flight (TOF) of ultrasonic signal to estimate the distance between a
receiver node and a transmitter node. TELIAMADE system consists of a set of wireless
nodes equipped with a radio module for communication and a module for the transmission
and reception of ultrasound. The access to the ultrasonic channel is managed by applying
a synchronization algorithm based on a time-division multiplexing (TDMA) scheme.
The ultrasonic signal is transmitted using a carrier frequency of 40 kHz and the TOF
measurement is estimated by applying a quadrature detector to the signal obtained at the
A/D converter output. Low sampling frequencies of 17.78 kHz or even 12.31 kHz are
possible using quadrature sampling in order to optimize memory requirements and to reduce
the computational cost in signal processing. The distance is calculated from the TOF taking
into account the speed of sound. An excellent accuracy in the estimation of the TOF is
achieved using parabolic interpolation to detect of maximum of the signal envelope at the
matched filter output. The signal phase information is also used for enhancing the TOF
measurement accuracy. Experimental results show a root mean square error (rmse) less
than 2 mm and a standard deviation less than 0.3 mm for pseudorange measurements in the
range of distances between 2 and 6 m. The system location accuracy is also evaluated by
applying multilateration. A sub-centimeter location accuracy is achieved with an average
rmse of 9.6 mm.},
organization = {Junta de Andalucía

P08-TIC-03886},
publisher = {Mdpi},
keywords = {Indoor positioning},
keywords = {Ultrasound time-of-flight},
keywords = {Wireless sensor network},
keywords = {Low-power},
title = {Ultrasound Indoor Positioning System Based on a Low-Power Wireless Sensor Network Providing Sub-Centimeter Accuracy},
doi = {10.3390/s130303501},
author = {Medina, Carlos and Segura Luna, José Carlos and Torre Vega, Ángel De La},
}