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Computational Efficiency Improvement for Unaided Weak GPS Signal Acquisition

Published online by Cambridge University Press:  12 March 2012

Wen Zhang*
Affiliation:
(National University of Defense Technology, Changsha, China)
Mounir Ghogho
Affiliation:
(University of Leeds, United Kingdom; International University of Rabat, Morocco)

Abstract

Acquisition of unaided weak Global Positioning System (GPS) signals requires long coherent integration time and thus all the possible navigation data bit combination paths have to be searched. In this paper, to improve the computational efficiency, the Improved Fast Modified Double-Block Zero Padding (IFMDBZP) algorithm using the Optimal Path Search Method (OPSM) is proposed instead of the FMDBZP algorithm using the All Paths Search Method (APSM). The proposed method consists of unlikely data bit combination path elimination by applying the Viterbi algorithm during each coherent integration step to improve the FMDBZP algorithm. The analyses show that the proposed OPSM can reduce the computation calculations and save memory space without suffering any loss compared to the APSM. And the longer the coherent integration time is, the more benefit one can gain from the proposed method. The simulation results also show that the IFMDPZP algorithm using the proposed OPSM has the same acquisition performance as the APSM.

Type
Research Article
Copyright
Copyright © The Royal Institute of Navigation 2012

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References

REFERENCES

Cormen, T., Leisersen, C. (1990). Introduction to Algorithms. MIT Press, Boston.Google Scholar
He, S. and Torkelson, M. (1996). Computing Partial DFT for Comb Spectrum Evaluation. IEEE Signal Processing Letters, 3(6), 173175.Google Scholar
Heckler, G. W. and Garrison, J. L. (2009). Implementation and Testing of an Unaided Method for the Acquisition of Weak GPS C/A Code Signals. Navigation, 56(4), 241259.CrossRefGoogle Scholar
Lin, D. M. and Tsui, L. B. Y. (2000). Comparison of Acquisition Methods for Software GPS Receiver. Proceedings of ION GPS-2000.Google Scholar
Lin, D. M., Tsui, L. B. Y. and Howell, D. (1999). Direct P(Y)-Code Acquisition Algorithm for Software GPS Receivers. Proceedings of ION GPS-1999.Google Scholar
Misra, P. and Enge, P. (2001). Global Positioning System: Signals, Measurements, and Performance. Ganga-Jamuna Press.Google Scholar
Parkinson, B. and Spilker, J. (1996). Global Positioning System: Theory and Applications. American Institute of Aeronautics and Astronautics.CrossRefGoogle Scholar
Sorensen, H. V. and Burrus, C. S. (1993). Efficient Computation of the DFT with Only a Subset of Input or Output Points. IEEE Transactions on Signal Processing, 41(3), 11841200.CrossRefGoogle Scholar
Tsui, J. B. Y. (2004). Fundamentals of Global Positioning System Receivers: A Software Approach (Second Edition). Wiley-Interscience.CrossRefGoogle Scholar
Van Nee, D. J. R. and Coenen, A. J. R. M. (1991). New Fast GPS Code-Acquisition Technique Using FFT. IEEE Electronics Letters, 27(2).CrossRefGoogle Scholar
Wild, R. de, Nieuwkerk, L. R., and Sittruyen, J. S van. (1987). Method for Partial Spectrum Computation. IEE Proceedings, Part F, Communications Radar and Signal Processing, 134(7), 659666.CrossRefGoogle Scholar
Yang, C. (2001). Zoom, Pruning, and Partial FFT for GPS Signal Tracking. Proceedings of the Institute of Navigation's ION NTM 2001.Google Scholar
Ziedan, N. I. (2006). GNSS Receivers for Weak Signals. Artech House, London.Google Scholar
Ziedan, N. I. and Garrison, J. L. (2004). Unaided Acquisition of Weak GPS Signals Using Circular Correlation or Double-Block Zero Padding. Position Location and Navigation Symposium (PLANS). 461470.CrossRefGoogle Scholar