Hybrid A-GPS and Ranging for Handset Positioning

Neil Harper and Martin Dawson

Abstract:	This paper investigates the process of hybridizing A-GPS with ranging signals. The and the expected accuracy results are outlined through a series of experiments. The accuracy results depend on the accuracy of the ranging technology used; this paper shows results for range measurements of different accuracies. The ranging signals may be from sources such as cellular network measurements (for example, Round-Trip Time (RTT) in a UMTS network, Timing Advance (TA) in a GSM network), Uplink Time Difference of Arrival (U-TDOA) measurements, WiFi, DTV or other signals. This study uses simulated range measurements to investigate expected accuracy and yield benefits. This paper shows the results of simulations that are worstcase situations. These are the situations where there are not enough GPS satellites to make a GPS-only location calculation. The tests show the results of combining two or three GPS satellite measurements with simulated range measurements.
Published in:	Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007) September 25 - 28, 2007 Fort Worth Convention Center Fort Worth, TX
Pages:	579 - 586
Cite this article:	Harper, Neil, Dawson, Martin, "Hybrid A-GPS and Ranging for Handset Positioning," Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007), Fort Worth, TX, September 2007, pp. 579-586.
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