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http://dx.doi.org/10.5302/J.ICROS.2011.17.1.61

Performance Analysis of Signal Acquisition in L2C Assisted GPS Receivers  

Song, Seung-Hun (Chungnam National University)
Park, Ji-Won (Chungnam National University)
Park, Ji-Hee (LIG Nex1)
Sung, Tae-Kyung (Chungnam National University)
Publication Information
Journal of Institute of Control, Robotics and Systems / v.17, no.1, 2011 , pp. 61-67 More about this Journal
Abstract
The GPS new civil signal is modulated on the L2 carrier at a frequency of 1227.6MHz. The L2C signal is composed of two multiplexed code signals, which include CM code with a 10,230 chip sequency repeating every 20ms, and CL code which has a 767,250 chip sequency repeating every 1.5 seconds. Thus, the new civil signal have much improved cross correlation properties so that the position fixing can be possible even with very weak signals. However, it requires very long acquisition time because of its long code length. This paper presents an efficient signal acquisition method for L2C AGPS receiver. Snapshot mode and coarse time assistance are assumed and total integration time is given by 1.5 sec. By SNR worksheet and computer simulation, it is proven that L2C signal can be acquired with very weak power less than -150dBm. Considering the acquisition time and the sensitivity, it is recommended that the highest power signal is acquired with CM code first to reduce TTFF. By the timing synchronization, at this time, search space of the code phase for other signals can be greatly reduced so that CL code can be used in signal acquisition to maximize sensitivity with small computation.
Keywords
L2C; assisted GPS; sensitivity; TTFF;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
Times Cited By SCOPUS : 1
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1 D. W. Im, S. W. Moon, C. S. Park, and S. J. Lee, “The fast signal acquisition scheme for a GPS L1/L2C correlator,” Journal of Institute of Control,Robotics and Systems, vol. 12, no. 8, pp. 765-772, Aug. 2006.   과학기술학회마을   DOI
2 D. J. Cho, C. S. Park, and S. J. Lee, “An assisted GPS acquisition method using L2 civil signal in weak signal environment,” Journal of Global Positioning Systems, vol. 3, no. 1-2, pp. 25-31, 2004.   DOI
3 A. R. A. Moghaddam, R. Watson, G. Lachapelle, and J. Nielsem, “Exploiting the orthogonality of L2C code delays for a fast acquisition,” ION GNSS 2006, Fort Worth, TX., pp. 1233-1241, Sep. 2006.
4 J. H. Park, H. J. Im, S. H. Song, and T. K. Sung, “Performance analysis of a residual frequency estimator for weak AGPS signals in frequency domain,” Journal of Institute of Control,Robotics and Systems, vol. 16, no. 7, pp. 720-725, Jul. 2010.   과학기술학회마을   DOI   ScienceOn
5 S. Cassian, M. Daniel, and M. Heinz, “The squaring-loss paradox,” ION GNSS 20th International Technical Meeting of the Satellite Division, Forth Worth, TX., Sep. 2007.
6 R. D. Fontana, W. Cheung, P. M. Novak, and T. Stansell, “The new L2 civil signal,” in Proc. of th 11th International Technical Meeting of the Satellite Division of the Institute of Navigation, pp. 617-631, Sep. 2001.
7 F. V. Diggelen, AGPS: Assisted GPS, GNSS, and SBAS, Artech House, 2009.