Title :
Ultrasonic beacon-based Local Positioning System using Loosely Synchronous codes
Author :
Pérez, M.C. ; Ureña, J. ; Hernández, A. ; De Marziani, C. ; Jiménez, A. ; Villadangos, J.M. ; Álvarez, F.
Author_Institution :
Univ. of Alcala, Alcala de Henares
Abstract :
This work presents the development of a local positioning system (LPS), based on the transmission of ultrasonic signals, which have been previously encoded by loosely synchronous (LS) codes. The LPS consists of several ultrasonic emitters located at known positions in the environment, and of a portable receiver that computes its position by measuring the differences in times of arrival (DTOA) between a reference emitter and the others. LS codes exhibit an interference free window (IFW) in the auto-correlation and cross-correlation functions. Therefore, if the relative time-offset of the codes are within the IFW, it is possible to have simultaneous emissions without interference, as well as to reduce the multipath effect.
Keywords :
correlation methods; interference (signal); radio receivers; time-of-arrival estimation; ultrasonic transducers; ultrasonic transmission; asynchronous detection; autocorrelation function; cross-correlation function; differences in times of arrival; interference free window; loosely synchronous codes; multipath effect; receiver; reference emitter; ultrasonic beacon-based local positioning system; ultrasonic emitter; ultrasonic signal transmission; ultrasonic transducer; Acoustic emission; Acoustic measurements; Autocorrelation; Intersymbol interference; Mobile robots; Multiaccess communication; Multiple access interference; Position measurement; Radio frequency; Ultrasonic variables measurement; Acoustic LPS; DS-CDMA; IFW; ISI; LS-codes; MAI; asynchronous detection;
Conference_Titel :
Intelligent Signal Processing, 2007. WISP 2007. IEEE International Symposium on
Conference_Location :
Alcala de Henares
Print_ISBN :
978-1-4244-0830-6
Electronic_ISBN :
978-1-4244-0830-6
DOI :
10.1109/WISP.2007.4447594
