DocumentCode :
991026
Title :
Experimental Evaluation of Location Methods Based on Signal-Strength Measurements
Author :
Laitinen, Heikki ; Juurakko, Suvi ; Lahti, Timo ; Korhonen, Risto ; Lähteenmäki, Jaakko
Author_Institution :
Tech. Res. Centre of Finland, Espoo
Volume :
56
Issue :
1
fYear :
2007
Firstpage :
287
Lastpage :
296
Abstract :
The accuracy of location methods based on received-signal-strength (RSS) measurements is highly variable, but the underlying causes are not well known. In this paper, narrowband measurements at five VHF frequencies are used to evaluate the accuracy of RSS-based location algorithms. The least squares algorithm is the most accurate if the propagation model is unbiased. Location error increases linearly with mean distance from transmitters and with RSS variation caused by shadow fading or varying antenna gain. Since shadow fading increases with frequency, location accuracy decreases with frequency. A satisfactory approximation of location accuracy in a given network is obtained by the error estimates that are based on linearization but modified when the receiver is close to one transmitter. Kalman filtering performed on the estimated coordinates removes the largest location errors, but it does not improve the median accuracy significantly due to the correlated shadowing process
Keywords :
Kalman filters; fading; least squares approximations; matrix algebra; mobile radio; Kalman filtering; antenna gain; least squares algorithm; location error; location methods; received-signal-strength measurements; shadow fading; Antenna measurements; Antennas and propagation; Fading; Filtering; Frequency measurement; Kalman filters; Least squares approximation; Least squares methods; Narrowband; Transmitters; Kalman filtering; location accuracy; location estimation; radio propagation; received signal strength (RSS);
fLanguage :
English
Journal_Title :
Vehicular Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9545
Type :
jour
DOI :
10.1109/TVT.2006.883785
Filename :
4067131
Link To Document :
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