Skip to main content
  • Research Article
  • Open access
  • Published:

Feedforward Delay Estimators in Adverse Multipath Propagation for Galileo and Modernized GPS Signals

Abstract

The estimation with high accuracy of the line-of-sight delay is a prerequisite for all global navigation satellite systems. The delay locked loops and their enhanced variants are the structures of choice for the commercial GNSS receivers, but their performance in severe multipath scenarios is still rather limited. The new satellite positioning system proposals specify higher code-epoch lengths compared to the traditional GPS signal and the use of a new modulation, the binary offset carrier (BOC) modulation, which triggers new challenges in the delay tracking stage. We propose and analyze here the use of feedforward delay estimation techniques in order to improve the accuracy of the delay estimation in severe multipath scenarios. First, we give an extensive review of feedforward delay estimation techniques for CDMA signals in fading channels, by taking into account the impact of BOC modulation. Second, we extend the techniques previously proposed by the authors in the context of wideband CDMA delay estimation (e.g., Teager-Kaiser and the projection onto convex sets) to the BOC-modulated signals. These techniques are presented as possible alternatives to the feedback tracking loops. A particular attention is on the scenarios with closely spaced paths. We also discuss how these feedforward techniques can be implemented via DSPs.

References

  1. Hein GW, Godet J, Issler JL, Martin JC, Pratt T, Lucas R: Status of Galileo frequency and signal design. CDROM Proceedings of the International Technical Meeting of the Institute of Navigation (ION-GPS '02), September 2002, Portland, Ore, USA

    Google Scholar 

  2. Hein GW, Irsigler M, Avila Rodriguez JA, Pany T: Performance of Galileo L1 signal candidates. CDROM Proceedings of European Navigation Conference GNSS, May 2004, Rotterdam, The Netherlands

    Google Scholar 

  3. Barker BC, Betz JW, Clark JE, et al.: Overview of the GPS M code signal. CDROM Proceedings of the ION National Meeting; Navigating into the New Millennium, January 2000, Anaheim, Calif, USA

    Google Scholar 

  4. Betz JW: The offset carrier modulation for GPS modernization. Proceedings of the National Technical Meeting of the Institute of Navigation (ION-NTM '99), January 1999, San Diego, Calif, USA 639–648.

    Google Scholar 

  5. Betz JW, Goldstein DB: Candidate designs for an additional civil signal in GPS spectral bands. In Technical Papers. MITRE, Bedford, Mass, USA; January 2002.

    Google Scholar 

  6. Simon MK, Omura JK, Scholtz RA, Levitt BK: Spread Spectrum Communication Handbook. revised edition. McGraw-Hill, New York, NY, USA; 1994.

    Google Scholar 

  7. Játiva RE, Vidal J: First arrival detection for positioning in mobile channels. Proceedings of the 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC '02), September 2002, Lisbon, Portugal 4: 1540–1544.

    Article  Google Scholar 

  8. Lakhzouri A, Lohan ES, Hamila R, Renfors M: Extended Kalman filter channel estimation for line-of-sight detection in WCDMA mobile positioning. EURASIP Journal on Applied Signal Processing 2003, 2003(13):1268–1278. 10.1155/S1110865703306018

    MATH  Google Scholar 

  9. Lohan ES: Multipath delay estimators for fading channels with applications in CDMA receivers and mobile positioning, M.S. thesis. Tampere University of Technology, Tampere, Finland; October 2003.

    Google Scholar 

  10. Vidal J, Najar M, Játiva RE: High resolution time-of-arrival detection for wireless positioning systems. Proceedings of IEEE 56th Vehicular Technology Conference (VTC '02), September 2002, Vancouver, BC, Canada 4: 2283–2287.

    Article  Google Scholar 

  11. Yousef NR, Sayed AH: Detection of fading overlapping multipath components for mobile positioning systems. Proceedings of IEEE International Conference on Communications (ICC '01), June 2001, Helsinki, Finland 10: 3102–3106.

    Google Scholar 

  12. Colclough DD, Titlebaum EL: Delay-doppler POCS for specular multipath. Proceedings of IEEE International Conference on Acoustic, Speech, and Signal Processing (ICASSP '02), May 2002, Orlando, Fla, USA 4: 3940–3943.

    Google Scholar 

  13. Fock G, Baltersee J, Schulz-Rittich P, Meyr H: Channel tracking for rake receivers in closely spaced multipath environments. IEEE Journal on Selected Areas in Communications 2001, 19(12):2420–2431. 10.1109/49.974607

    Article  Google Scholar 

  14. Kostić ZZ, Pavlović GG: Resolving subchip-spaced multipath components in CDMA communication systems. IEEE Transactions on Vehicular Technology 1999, 48(6):1803–1808. 10.1109/25.806773

    Article  Google Scholar 

  15. Van Nee RDJ: The multipath estimating delay locked loop. Proceedings of IEEE 2nd International Symposium on Spread Spectrum Techniques and Applications (ISSSTA '92), November–December 1992, Yokohama, Japan 39–42.

    Chapter  Google Scholar 

  16. Yousef NR, Sayed AH: A new adaptive estimation algorithm for wireless location finding systems. Proceedings of 33rd Asilomar Conference on Signals, Systems, and Computers, October 1999, Pacific Grove, Calif, USA 1: 491–495.

    Google Scholar 

  17. Baltersee J, Fock G, Schulz-Rittich P: Adaptive code-tracking receiver for direct-sequence code division multiple access (CDMA) communications over multipath fading channels and method for signal processing in a Rake receiver. US Patent Application Publication, US 2001/0014114 A1 (Lucent Technologies), August 2001

    Google Scholar 

  18. Bischoff R, Häb-Umbach R, Schulz W, Heinrichs G: Employment of a multipath receiver structure in a combined GALILEO/UMTS receiver. Proceedings of 55th Vehicular Technology Conference (VTC '02), May 2002, Birmingham, Ala, USA 4: 1844–1848.

    Google Scholar 

  19. Chen K-C, Davisson LD: Analysis of SCCL as a PN-code tracking loop. IEEE Transactions on Communications 1994, 42(11):2942–2946. 10.1109/26.328975

    Article  Google Scholar 

  20. Fine P, Wilson W: Tracking algorithms for GPS offset carrier signals. Proceedings of the National Technical Meeting of the Institute of Navigation (ION-NTM '99), January 1999, San Diego, Calif, USA

    Google Scholar 

  21. Laxton M: Analysis and simulation of a new code tracking loop for GPS multipath mitigation, M.S. thesis. Air Force Institute of Technology, Dayton, Ohio, USA; 1996.

    Google Scholar 

  22. Van Dierendonck AJ, Fenton P, Ford T: Theory and performance of narrow correlator spacing in a GPS receiver. Navigation 1992, 39(3):265–283.

    Article  Google Scholar 

  23. Irsigler M, Eissfeller B: Comparison of multipath mitigation techniques with consideration of future signal structures. Proceedings of the International Technical Meeting of the Institute of Navigation (ION-GPS/GNSS '03), September 2003, Portland, Ore, USA 2584–2592.

    Google Scholar 

  24. McGraw GA, Braasch M: GNSS multipath mitigation using high resolution correlator concepts. Proceedings of the National Technical Meeting of the Institute of Navigation (ION-NTM '99), January 1999, San Diego, Calif, USA 333–342.

    Google Scholar 

  25. Garin L, Rousseau JM: Enhanced strobe correlator multipath rejection for code and carrier. Proceedings of the International Technical Meeting of the Institute of Navigation (ION-GPS '97), September 1997, Kansas City, Mo, USA 559–568.

    Google Scholar 

  26. Fenton P, Smith B, Jones J: Theory and performance of the pulse aperture correlator. NovAtel, Calgary, Alberta, Canada; September 2004.https://doi.org/www.novatel.com/customer_support/alltechpapers.html (active May 2005),

    Google Scholar 

  27. Weill LR: Multipath mitigation—how good can it get with new signals? GPS World 2003, 16(6):106–113.

    Google Scholar 

  28. Sheen WH, Stüber GL: A new tracking loop for direct sequence spread spectrum systems on frequency-selective fading channel. Proceedings of IEEE International Conference on Communications (ICC '95), January 1995, Seattle, Wash, USA 3: 1364–1368.

    Article  Google Scholar 

  29. Iltis RA: Joint estimation of PN code delay and multipath using the extended Kalman filter. IEEE Transactions on Communications 1990, 38(10):1677–1685. 10.1109/26.61437

    Article  Google Scholar 

  30. Lohan ES, Hamila R, Lakhzouri A, Renfors M: Highly efficient techniques for mitigating the effects of multipath propagation in DS-CDMA delay estimation. IEEE Transactions on Wireless Communications 2005, 4(1):149–162.

    Article  Google Scholar 

  31. Fuchs J-J: Multipath time-delay detection and estimation. IEEE Transactions on Signal Processing 1999, 47(1):237–243. 10.1109/78.738263

    Article  Google Scholar 

  32. Lohan ES, Renfors M: Feedforward approach for estimating the multipath delays in CDMA systems. Proceedings of Nordic Signal Processing Symposium (NORSIG '00), June 2000, Kolmården, Sweden 1: 125–128.

    Google Scholar 

  33. Kostić ZZ, Sezan MI, Titlebaum EL: Estimation of the parameters of a multipath channel using set-theoretic deconvolution. IEEE Transactions on Communications 1992, 40(6):1006-1011. 10.1109/26.142791

    Article  Google Scholar 

  34. Hamila R: Synchronization and multipath delay estimation algorithms for digital receivers, M.S. thesis. Tampere University of Technology, Tampere, Finland; June 2002.

    Google Scholar 

  35. Hamila R, Lohan ES, Renfors M: Novel technique for multipath delay estimation in GPS receivers. Proceedings of International Conference on Third Generation Wireless and Beyond (3GWireless '01), June 2001, San Francisco, Calif, USA 1: 993–998.

    Google Scholar 

  36. Lohan ES, Lakhzouri A, Renfors M: Spectral shaping of Galileo signals in the presence of frequency offsets and multipath channels. Proceedings of 14th IST Mobile & Wireless Communications Summit, June 2005, Dresden, Germany

    MATH  Google Scholar 

  37. Lohan ES, Lakhzouri A, Renfors M: Double Binary-Offset-Carrier (DBOC) modulation technique for satellite systems. In Tech. Rep. ISBN 952-15-1348-9, ISSN 1459.4617. Institute of Communications Engineering, Tampere University of Technology, Tampere, Finland; April 2005.

    Google Scholar 

  38. Rebeyrol E, Macabiau C, Lestarquit L, Ries L, Issler JL: BOC power spectrum densities. CDROM Proceedings of the National Technical Meeting of the Institute of Navigation (ION-NTM '05), January 2005, San Diego, Calif, USA

    Google Scholar 

  39. Bastide F, Julien O, Macabiau C, Roturier B: Analysis of L5/E5 acquisition, tracking and data demodulation thresholds. Proceedings of the International Technical Meeting of the Institute of Navigation (ION-GPS '02), September 2002, Portland, Ore, USA 2196–2207.

    Google Scholar 

  40. Rappaport TS: Wireless Communications: Principles and Practice. Prentice-Hall, Englewood Cliffs, NJ, USA; 1996.

    MATH  Google Scholar 

  41. Betaille D, Maenpa J, Cross P: Overcoming the limitations of the phase multipath mitigation window. Proceedings of the International Technical Meeting of the Institute of Navigation (ION-GPS/GNSS '03), September 2003, Portland, Ore, USA 2102–2111.

    Google Scholar 

  42. Hamila R, Lohan ES, Renfors M: Subchip multipath delay estimation for downlink WCDMA system based on Teager-Kaiser operator. IEEE Communications Letters 2003, 7(1):1–3. 10.1109/LCOMM.2002.807439

    Article  Google Scholar 

  43. Lohan ES, Renfors M: A novel deconvolution approach for high accuracy LOS estimation in WCDMA environments. Proceedings of 7th International Symposium on Signal Processing and Its Applications (ISSPA '03), July 2003, Paris, France 2: 299–302.

    Google Scholar 

  44. Kostic Z, Pavlovic G: Resolving sub-chip spaced multipath components in CDMA communication systems. Proceedings of 43rd IEEE Vehicular Technology Conference (VTC '93), May 1993, Secaucus, NJ, USA 1: 469–472.

    Article  Google Scholar 

  45. Trussell H, Civanlar M: Feasible solution in signal restoration. IEEE Transactions on Acoustics, Speech, and Signal Processing 1984, 32(2):201–212. 10.1109/TASSP.1984.1164297

    Article  Google Scholar 

  46. Kaiser JF: On a simple algorithm to calculate the 'energy' of a signal. Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP '90), April 1990, Albuquerque, NM, USA 1: 381–384.

    Google Scholar 

  47. Baltersee J: Modeling & simulating fading channels for systems with smart antennas. Proceedings of the 9th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC '98), September 1998, Boston, Mass, USA 2: 957–961.

    Article  Google Scholar 

  48. Baines R: The DSP bottleneck. IEEE Communication Magazine 1995, 33(5):46–54. 10.1109/35.392999

    Article  MathSciNet  Google Scholar 

  49. Lackey RI, Upmal DW: Speakeasy: the military software radio. IEEE Communications Magazine 1995, 33(5):56–61. 10.1109/35.392998

    Article  Google Scholar 

  50. Buracchini E: Software radio concept. IEEE Communications Magazine 2000, 38(9):138–143. 10.1109/35.868153

    Article  Google Scholar 

  51. Tuttlebee WHW: Software radio technology: a European perspective. IEEE Communications Magazine 1999, 37(2):118–123. 10.1109/35.747260

    Article  Google Scholar 

  52. Texas Instruments : Code Composer Studio User's Guide. March 2005

  53. Texas Instruments : Code Composer Studio v3.0 Getting Started Guide. May 2000

  54. Texas Instruments : TMS320C54x Optimizing C/C++ Compiler User's Guide. October 2002

  55. Texas Instruments : TI, TMS320C6x Optimizing C Compiler: User's Guide. February 1998

  56. Galileo Joint Undertaking (GJU) : Galileo standardization document for 3gpp. GJU webpages, (active December 2005), May 2005, https://doi.org/www.galileoju.com

  57. Texas Instruments : TMS320C64x Datasheet. March 2005, https://doi.org/www.ti.com

  58. Texas Instruments : TMS320C55x Datasheet. November 2004, https://doi.org/www.ti.com

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Elena Simona Lohan.

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 2.0 International License ( https://creativecommons.org/licenses/by/2.0 ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Reprints and permissions

About this article

Cite this article

Lohan, E.S., Lakhzouri, A. & Renfors, M. Feedforward Delay Estimators in Adverse Multipath Propagation for Galileo and Modernized GPS Signals. EURASIP J. Adv. Signal Process. 2006, 050971 (2006). https://doi.org/10.1155/ASP/2006/50971

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1155/ASP/2006/50971

Keywords