Title :
Prior NLOS Ratio Estimate and Measurements Rating in Wireless Cellular Networks
Author :
Mazuelas, S. ; Lago, F.A. ; Blas, J. ; Fernandez, P. ; Lorenzo, R.M. ; Abril, E.J.
Author_Institution :
CEDETEL Center for the Dev. of Telecommun., Valladolid
Abstract :
The main drawback to improve the precision in cellular location systems based on time delays is the presence of non-line-of-sight (NLOS) propagation, introducing significant and hardly predictable errors in the measurements used in location. In this paper we propose a technique to previously detect and estimate the NLOS ratio present in the measurements. A comprehensive research on the Time of Arrival (TOA) dependence on the NLOS ratio existing in the measurements leads to estimate that ratio from the deviation calculated directly from the available measurements. NLOS detection and ratio estimate is very useful to classify and weight the measurements available in order to perform the following location estimate with the most accurate ones. Several simulations have been conducted to show the precision of ratio estimate and the measurements rating based on it.
Keywords :
cellular radio; time-of-arrival estimation; NLOS ratio estimate; TOA; cellular location systems; location estimate; nonline-of-sight propagation; time delays; time of arrival dependence; wireless cellular networks; Base stations; Land mobile radio cellular systems; Measurement standards; Noise measurement; Performance evaluation; Position measurement; Random variables; Telematics; Time measurement; Weight measurement;
Conference_Titel :
Vehicular Technology Conference, 2007. VTC-2007 Fall. 2007 IEEE 66th
Conference_Location :
Baltimore, MD
Print_ISBN :
978-1-4244-0263-2
Electronic_ISBN :
1090-3038
DOI :
10.1109/VETECF.2007.263
