Two-step Low Complexity GPS Signal Acquisition

Fabrício Costa Silva, Samuel Xavier-de-Souza, Luiz F. Q. Silveira, Francisco das Chagas Mota, Glauberto Leilson Alves de Albuquerque, Carlos Alberto Valderrama

Abstract:	Before a receiver processes its first location, acquisition is the most time consuming part of processing a GPS signal and therefore represents a bottleneck for many applications. Several acquisition methods exist but are subject to tradeoffs. A method that combines less hardware resources with faster response time and lower computational complexity is still a challenge nowadays. In this paper we propose a two-step approach that roughly shares the same amount of resources of the conventional sequential time domain acquisition method but has a much lower computational complexity in a successful satellite search. In the first step of this approach, a coarse search is performed incrementally in a low resolution search domain. During this phase the method identifies promising regions using a new metric especially developed for this purpose. Upon identification of a promising region, a fine search is triggered around the expected frequency in the full resolution search domain. From this phase, the search ends with the given satellite acquired or it returns to the point where it was interrupted in the incremental coarse search. Results show that due to the lower computational complexity of the new method, successful acquisition is much faster than the conventional method while being expected to need roughly the same amount of hardware resources.
Published in:	Proceedings of the ION 2015 Pacific PNT Meeting April 20 - 23, 2015 Marriott Waikiki Beach Resort & Spa Honolulu, Hawaii
Pages:	629 - 634
Cite this article:	Silva, Fabrício Costa, Xavier-de-Souza, Samuel, Silveira, Luiz F. Q., Mota, Francisco das Chagas, de Albuquerque, Glauberto Leilson Alves, Valderrama, Carlos Alberto, "Two-step Low Complexity GPS Signal Acquisition," Proceedings of the ION 2015 Pacific PNT Meeting, Honolulu, Hawaii, April 2015, pp. 629-634.
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