Browse > Article
http://dx.doi.org/10.5302/J.ICROS.2004.10.1.096

An Efficient Assisted-GPS Acquisition Method in Weak Signal Environment  

박상현 (충남대학교 BK21정보통신인력양성사업단)
이상정 (충남대학교 공과대학 전기정보통신공학부)
Publication Information
Journal of Institute of Control, Robotics and Systems / v.10, no.1, 2004 , pp. 96-102 More about this Journal
Abstract
For sensitivity enhancement, the general assisted-GPS acquisition method adopts not only the coherent accumulation technique but also the non-coherent accumulation technique since the long coherent accumulation period increases the number of frequency search cells. But the non-coherent accumulation technique causes tile squaring loss, which is a dominant factor among the acquisition losses of assisted GPS dealing with weak GPS signals. This paper derives the squaring loss of the previous assisted-GPS acquisition method and proposes an assisted-GPS acquisition method for solving the problem of squaring loss in weak signal environment. In this paper, it is explained that the proposed assisted-GPS acquisition method prevents the squaring loss using a coupled coherent accumulation technique and the number of search cells of the proposed assisted-GPS acquisition method is much smaller than that of the previous assisted-GPS acquisition method. Finally, through the simulation by the GPS simulator, the acquisition success rate of the proposed assisted-GPS acquisition method is compared with that of the previous assisted-GPS acquisition method and the acquisition improvements are shown in weak signal environment.
Keywords
assisted-GPS acquisition; weak signal; squaring loss; coupled coherent accumulation;
Citations & Related Records
연도 인용수 순위
  • Reference
1 /
[ R.N.McDonough;A.D.Whalen ] / Detection of signals in noise
2 /
[ R.L.Peterson(et. al.) ] / Introduction to spread spectrum communications
3 J. J. Caffery and G. L. Stuber, 'Overview of radiolocation in CDMA cellular systems', IEEE Communication Magazine, vol. 46, no, 4, pp. 38-45, April 1998   DOI   ScienceOn
4 G. M Djuknic and R. E .Richton, 'Geolocation and assisted GPS', Computer, vol. 34, no. 2, pp. 123-125, February 2001   DOI   ScienceOn
5 T. Haddrell and A. R. Pratt, 'Understanding the indoor GPS signal', in Proceedings of the 14th International Technical Meeting of the Satellite Division of the Institute of Navigation, pp. 1487-1499, 11-14 September 2001
6 N. F. Krasner, Fast acquisition high sensitivity GPS receiver, US Pstent 6289041 B1, Patent and Trademark Office, Washington D.C., 1998
7 M. M. Chansarker and L. Garin, 'Asquisition of GPS signals at very low signal to noise ratio', Proceeding of the ION 2000 National Technical Meeting, pp. 731-737, 26-28 January 2000
8 J.-C. Lin, 'Differentially coherent PN code acquisition with full-period correlation in chip-synchronous DS/SS receivers', IEEE Transactions on Communications, vol. 50, no. 5, pp. 698-702, May 2002   DOI   ScienceOn
9 R. L. Peterson et. al., Introduction to spread spectrum communications, Prentice-Hall, Inc., 1995
10 S. Soliman, S. Glazko, and P. Agashe, 'GPS receiver sensitivity enhancement in wireless applications', Proceedings of 1999 IEEE MTT-S Symposium, pp. 181-186, 21-24 February 1999   DOI
11 TR45, Position deternination service standard for dual mode spread systems, TIA/EIA/IS-801, October 15, 1999
12 R. N. McDonough and A. D. Whalen, 'Detection of signals in noise, New York: Acadermic Press, 1995