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This article is part of the series Wireless Location Technologies and Applications.

Open Access Research Article

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

Elena Simona Lohan*, Abdelmonaem Lakhzouri and Markku Renfors

Author Affiliations

Institute of Communications Engineering, Tampere University of Technology, P.O. Box 553, Tampere 33101, Finland

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EURASIP Journal on Advances in Signal Processing 2006, 2006:050971  doi:10.1155/ASP/2006/50971


The electronic version of this article is the complete one and can be found online at: http://asp.eurasipjournals.com/content/2006/1/050971


Received:31 May 2005
Revisions received:8 March 2006
Accepted:29 March 2006
Published:25 May 2006

© 2006 Lohan et al.

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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. GW Hein, J Godet, JL Issler, JC Martin, T Pratt, R Lucas, 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

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

  3. BC Barker, JW Betz, JE Clark, 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

  4. JW Betz, 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

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

  6. MK Simon, JK Omura, RA Scholtz, BK Levitt, Spread Spectrum Communication Handbook, d (McGraw-Hill, New York, NY, USA, 1994)

  7. RE Játiva, J Vidal, 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

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

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

  10. J Vidal, M Najar, RE Játiva, 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

  11. NR Yousef, AH Sayed, 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

  12. DD Colclough, EL Titlebaum, 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

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

  14. ZZ Kostić, GG Pavlović, Resolving subchip-spaced multipath components in CDMA communication systems. IEEE Transactions on Vehicular Technology 48(6), 1803–1808 (1999). Publisher Full Text OpenURL

  15. RDJ Van Nee, 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

  16. NR Yousef, AH Sayed, 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

  17. J Baltersee, G Fock, P Schulz-Rittich, 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

  18. R Bischoff, R Häb-Umbach, W Schulz, G Heinrichs, 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

  19. K-C Chen, LD Davisson, Analysis of SCCL as a PN-code tracking loop. IEEE Transactions on Communications 42(11), 2942–2946 (1994). Publisher Full Text OpenURL

  20. P Fine, W Wilson, 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

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

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

  23. M Irsigler, B Eissfeller, 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

  24. GA McGraw, M Braasch, 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

  25. L Garin, JM Rousseau, 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

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

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

  28. WH Sheen, GL Stüber, 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

  29. RA Iltis, Joint estimation of PN code delay and multipath using the extended Kalman filter. IEEE Transactions on Communications 38(10), 1677–1685 (1990). Publisher Full Text OpenURL

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

  31. J-J Fuchs, Multipath time-delay detection and estimation. IEEE Transactions on Signal Processing 47(1), 237–243 (1999). Publisher Full Text OpenURL

  32. ES Lohan, M Renfors, 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

  33. ZZ Kostić, MI Sezan, EL Titlebaum, Estimation of the parameters of a multipath channel using set-theoretic deconvolution. IEEE Transactions on Communications 40(6), 1006–1011 (1992). Publisher Full Text OpenURL

  34. R Hamila, in Synchronization and multipath delay estimation algorithms for digital receivers, M, ed. by . S. thesis (Tampere University of Technology, Tampere, Finland, June 2002)

  35. R Hamila, ES Lohan, M Renfors, 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

  36. ES Lohan, A Lakhzouri, M Renfors, 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

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

  38. E Rebeyrol, C Macabiau, L Lestarquit, L Ries, JL Issler, 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

  39. F Bastide, O Julien, C Macabiau, B Roturier, 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

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

  41. D Betaille, J Maenpa, P Cross, 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

  42. R Hamila, ES Lohan, M Renfors, Subchip multipath delay estimation for downlink WCDMA system based on Teager-Kaiser operator. IEEE Communications Letters 7(1), 1–3 (2003). Publisher Full Text OpenURL

  43. ES Lohan, M Renfors, 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

  44. Z Kostic, G Pavlovic, 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

  45. H Trussell, M Civanlar, Feasible solution in signal restoration. IEEE Transactions on Acoustics, Speech, and Signal Processing 32(2), 201–212 (1984). Publisher Full Text OpenURL

  46. JF Kaiser, 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

  47. J Baltersee, 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

  48. R Baines, The DSP bottleneck. IEEE Communication Magazine 33(5), 46–54 (1995). Publisher Full Text OpenURL

  49. RI Lackey, DW Upmal, Speakeasy: the military software radio. IEEE Communications Magazine 33(5), 56–61 (1995). Publisher Full Text OpenURL

  50. E Buracchini, Software radio concept. IEEE Communications Magazine 38(9), 138–143 (2000). Publisher Full Text OpenURL

  51. WHW Tuttlebee, Software radio technology: a European perspective. IEEE Communications Magazine 37(2), 118–123 (1999). Publisher Full Text OpenURL

  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, http://www), . galileoju.com webcite

  57. Texas Instruments, TMS320C64x Datasheet (March 2005, http://www), . ti.com webcite

  58. Texas Instruments, TMS320C55x Datasheet (November 2004, http://www), . ti.com webcite