Optimized Search Window Alignment for A-GPS

The best performance of assisted-global positioning system (A-GPS) positioning is obtained when fine time assistance is provided to the terminal, i.e., when information on the GPS time of week is provided, and is accurate to within a few microseconds. This paper presents a new method for the minimization of the size of the coarse acquisition (C/A) code search windows, around their so-provided window centers. The method accounts for 1) the geometrical shape of the initial region where the terminal is known to be located; 2) the location of the radio base station; and 3) the azimuth and elevation angles of each space vehicle. Benefits include a reduced computational complexity of the GPS signal acquisition or a corresponding sensitivity enhancement.

[1]  Elliott D. Kaplan Understanding GPS : principles and applications , 1996 .

[2]  Torbjörn Wigren,et al.  LOCATION COVERAGE AND SENSITIVITY WITH A-GPS , 2004 .

[3]  S. Tekinay Wireless Geolocation Systems and Services , 1998, IEEE Communications Magazine.

[4]  Torbjörn Wigren Adaptive Enhanced Cell-ID Fingerprinting Localization by Clustering of Precise Position Measurements , 2007, IEEE Transactions on Vehicular Technology.

[5]  Torbjörn Wigren,et al.  RTT Positioning in WCDMA , 2009, 2009 Fifth International Conference on Wireless and Mobile Communications.