Jaffrot, Emmanuel (2000) Estimation de canal très sélectif en temps et en fréquence pour les systèmes OFDM. PhD thesis Electronique et Communications, ENST - COMELEC Communication et Electronique, ENST.

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Abstract

High bit rates services focusing in the telecommunications domain is leading to an increasing interest for OFDM modulation in actual research. This technique is based on orthogonal modulating filters and doesn't need the use of an equalizer, but it requires the estimation of the channel frequency response for each transmitted symbol. Today's propagation contexts met in high bit rate mobile communications may be really tough to precisely estimate.
In this document, we propose two channel estimation methods for highly frequency and time selective channels, based on the Maximum a Posteriori criteria, processing block by block the re¬ceived signal. These algorithme use a channel model based on the orthogonal decomposition of the autocorrelation matrix of the channel obtained by means of the Karhunen-Loève orthogonal ex¬pansion theorem. We also present these new techniques performance compared to classical channel estimators and the robustness of those methods to an error on the channel statistics.

References

[1] L.R. Bahl, J. Cocke, F. Jelinek, and J. Raviv. Optimal decoding of linear codes for minimizing symbol error rate. IEEE Trans. on Information Theory, pages 284-287, Mar. 1974.
[2] M. Bellanger. Analyse des signaux et filtrage numérique adaptatif. Masson, Paris, 1989.
[3] C. Berrou and A. Glavieux. Near optimum error correcting coding and decoding: Turbo-codes. IEEE Trans. on Commun., 44(10) :1261-1271, Oct. 1996.
[4] C. Berrou, A. Glavieux, and P. Thitimajshima. Near shannon limit error-correcting coding and decoding: Turbo-codes. In ICC'93, pages 1064-1070, Geneva, Switzerland, May 1993. IEEE.
[5] S. B. Bulumulla. An adaptive diversity receiver for ofdm in fading channels. IEEE, 1998.
[6] S. B. Bulumulla, S. A. Kassam, and S. S. Venkatesh. A systematic approach to detecting ofdm signals in a fading channel. IEEE Trans. on Commun., 48(5), May. 2000.
[7] X. Cai and A. N. Akansu. A subspace method for blind channel identification in ofdm systems. IEEE, 2000.
[8] J. K. Cavers. An analysis of pilot symbol assisted modulation for rayleigh fading channels.
IEEE Trans. on Vehic. Tech., 40(4), Nov. 1991.
[9] M. X. Chang and Y. T. Su. 2d regression channel estimation for equalizing ofdm signals. In VTC72000. IEEE, 2000.
[10] R. W. Chang. Synthesis of band-limited orthogonal signals for multichannel data transmission.
The Bell System Tech. Journ., pages 1775-1796, Dec. 1966.
[11] A. Chini, Y. Wu, M. El-Tanany, and S. Mahmoud. Filtered decision feedback channel estimation for ofdm-based dtv terrestrial broadcasting system. IEEE Trans. on Broadcast., 44(1), Mar. 1998.
[12] N. Chotikakamthorn and H. Suzuki. On identifiability of ofdm blind channel estimation. In VTC799. IEEE, 1999.
[13] J. J. Van de Beek, O. Edfors, and P. O. Borjesson. Channel estimation in the uplink of an ofdm system.
[14] J. J. Van de Beek and et al. On channel estimation in ofdm systems. In Vehicul. Tech. Conf. VTC' 95, volume 2, pages 815-819, Chicago, IL, July 1995. IEEE.
[15] T. de Couasnon, R. Monnier, and J. B. Rault. Ofdm for digital tv broadcasting. Signal Proc., 39(1-2) :132, Sep. 1994.
[16] M. de Courville. Utilisation de bases orthogonales pour l'algorithmique adaptative et l'égalisa-tion des systèmes multiporteuses. PhD thesis, Telecom Paris, Paris, France, Oct. 1996.
[17] A. P. Dempster, N. M. Laird, and D. B. Rubin. Maximum-likelihood from incomplete data via the em algorithm. J. Roy. Statist. Soc., 39 :117, 1977.
[18] C. Douillard, M. Jézéquel, C. Berrou, A. Picart, P. Didier, and A. Glavieux. Iterative correction of intersymbol interference: Turbo-equalization. ETT, 6(5) :507-511, Sep.-Oct. 1995.
[19] D. E. Dudgeon and R. M. Mersereau. Multidimensional digital signal processing. Prentice-Hall, Englewood Cliffs, NJ, 1984.
[20] O. Edfors and et al. An application of the singular value decomposition to ofdm channel estimation.
[21] O. Edfors and et al. Ofdm channel estimation by singular value decomposition. IEEE Trans. on Commun., 46(7), Jul. 1998.
[22] V. Engels and H. Rohling. Differential modulation techniques for a 34 mbit/s radio channel using orthogonal frequency- division multiplexing. Wireless Pers. Commun., 2(1-2) :2944, 1995.
[23] V. Engels and H. Rohling. Multilevel differential modulation techniques (64-dapsk) for mul-ticarrier transmission systems. Eur. Trans. Telecommun. Rel. Technol., 6(6) :633-640, Nov. 1995.
[24] European Telecomunications Standards Institute ETSI. Radio broadcasting systems, digital audio broadcasting (dab) to mobile, portable and fixed receivers. In ETS 300 401, Valbonne, France, Feb. 1995.
[25] European Telecomunications Standards Institute ETSI. Digital broadcasting for television, sound and data services. In prETS 300 744(draft version 0.0.3), Avr. 1996.
[26] M. Feder and E. Weinstein. Parameter estimation of superimposed signals using the em algo rithm. Trans. Acoust., Speech and Signal Processing, 36 :477-489, Apr. 1988.
[27] B. Le Floch, M. Alard, and C. Berrou. Coded orthogonal frequency division multiplex. Pro-ceedings of the IEEE, 83(6) :982-996, June 1995.
[28] P. Frenger and A. Svensson. A decision directed coherent detector for ofdm. In Vehic. Tech. Conf. VTC'96, pages 1584-1588, Atlanta, GA, Apr. 1996. IEEE.
[29] C. N. Georghiades. Algorithms for joint sgnchronization an decoding. Elsevier, Amsterdam,
The Netherlands, 1992.
[30] C. N. Georghiades and J. C. Han. Optimum decoding of trellis-coded modulation in the presence of phase-errors. In Int. Sgmp. on Information Theorg and Its Applications (ISITA'90), Hawai,
Nov. 1990.
[31] C. N. Georghiades and D. L. Snyder. The expectation-maximization for symbol unsynchronized sequence detection. IEEE Trans. Commun., 39 :5461, Jan. 1991.
[32] R. Haas. Application des transmissions porteuses multiples aux communications radiomobiles.
Phd thesis, Ecole Nationale Supérieure des Télécommunications, Paris, France, Jan. 1996.
[33] A. A. Hassan and J. C. Belfiore. Rayleigh fading channel estimation using shmidt polynomials. In Vehic. Techn. Conf. VT'2000, pages 2098-2102. IEEE, 2000.
[34] R. W. Heath and G. B. Giannakis. Blind channel identification for multirate precoding and ofdm systems. In DSP'97, 1997.
[35] P. Hoëher. Tcm on frequency-selective land-mobile fading channels. In Tirrenia Int. Workshop Digit. Commun., Tirrenia, Italy, Sep. 1991.
[36] P. Hoëher, S. Kaiser, and P. Robertson. Two-dimensional pilot- symb ol- aided channel estimation by wiener filtering. IEEE, pages 1845-1848, 1997.
[37] M.H. Hsieh and C.H. Wei. Channel estimation for ofdm systems based on comb-type pilot arrangement in frequency selective fading channels. IEEE Trans. on Consumer Electr., 44(1), Feb. 1998.
[38] A. Huang and Y. Zhao. Estimating channel response from pilot subcarriers pairs for ofdm systems. IEEE, 1997.
[39] A. A. Hutter, R. Hasholzner, and J. S. Hammerschmidt. Channel estimation for mobile ofdm systems. IEEE, 1999.
[41] L. Jarbot. Combined decoding and channel estimation of ofdm systems in mobile radio net-works. IEEE, 1997.
[42] V.K. Jones and G. G. Raleigh. Channel estimation for wireless ofdm systems. IEEE, 1998.
[43] V. P. Kaasila. Performance analysis of an ofdm system using data-aided channel estimation. IEEE, 1999.
[44] G. K. Kaleh. Joint decoding and phase estimation via the expectation-maximization algorithm.
In Int. Sgmp. on Information Theorg, San Diego, CA, Jan. 1990.
[45] Lavielle. Discussion of meng and van dik's paper: The em algorithm - an old folk song to a fast new tune. J.R. Stat. Soc. B, 59(3) :556-557, 1997.
[46] Y. Li. Pilot- symb ol- aided channel estimation for ofdm in wireless systems. IEEE, 1999.
[47] L. R. Liporace. Maximum likelihood for multivariate observations of markov sources. IEEE Trans. on Inform. Theorg, IT-28 :729-734, Sep. 1982.
[48] V. Mignone, A. Morello, and M. Visintin. Cd3-ofdm: A new channel estimation method to improve the spectrum efficiency in digital terrestrial television systems. In International Broadcasting Convention. IEE, 14-18 Sep. 1995.
[49] J. W. Modestino. Reduced-complexity iterative maximum-likelihood sequence estimation on channels with memory. In Int. Sgmp. on Inform. Theorg, San Antonio, TX, Jan. 1993. IEEE.
[50] M. L. Moher and J. H. Lodge. Tcmp - a modulation and coding strategy for rician-fading channels. IEEE Journal on Select. Areas in Commun., 7(9) :1347-1355, Dec. 1989.
[51] J. K. Moon and S. I. Choi. Performance of channel estimation methods for ofdm systems in a multipath fading channels. IEEE Trans. on Consum. Electr., 46(1) :161-170, Feb. 2000.
[52] E. Moulines, P. Duhamel, J.-F. Cardoso, and S. Mayrargue. Subspace methods for the blind identification of multichannel fir filters. IEEE Trans. on Sig. Proc., 43(2) :516-525, Feb. 1995.
[53] B. Muquet and et al. A subspaced based blind and semi-blind channel indentification method for ofdm systems. IEEE, 1999.
[54] F. D. Nunes and J. M. N. Leitao. Nonlinear channel estimation in fading ofdm systems. In
Global Telecom. Conf. GLOBECOM'99. IEEE, 1999.
[56] R. F. Ormondroyd and E. A. Al-Susa. A high efficiency channel estimation and equalisation strategy for a broadband cofdm system.
[57] A. Picart, P. Didier, and A. Glavieux. Turbo-detection: a new approach to combat channel frequency selectivity. In ICC'97, Montreal, Canada, 8-12 June 1997.
[58] H. V. Poor. On parameter estimation in ds/ssma formats. In Advances in Communications and Control Sgstems, pages 5970, Baton Rouge, LA, Oct. 1988.
[59] J. G. Proakis. Digital Communications. McGraw-Hill, second edition, 1989.
[60] J. G. Proakis. Digital Communications. McGraw-Hill, third edition, 1995.
[61] C. Reiners and H. Rohling. Multicarrier transmission technique in cellular mobile communica-tions systems. In IEEE Vehic. Technol. Conf. (VTC'94), pages 1645-1649, Stockholm, Sweden, Jun. 1994.
[62] J. Rinne and M. Renfors. Pilot spacing in orthogonal frequency division multiplexing systems on practical channels. IEEE Trans. on Consum. Electr., 42(4) :959-962, Nov. 1996.
[63] H. Rohling and K. Bruninghaus. High rate ofdm-modem with quasi-coherent dapsk. 1997.
[64] H. Rohling and R. Grünheid. Multicarrier transmission technique in mobile communication systems. In RACE Mobile Commun. Summit, pages 270-276, Cascais, Nov. 1995.
[65] F. Said and A. H. Aghvami. Linear two dimensional pilot assisted channel estimation for ofdm systems. In Telecomm. 98. IEE, 29th Mar. - lst Apr. 1998.
[66] F. Said and A. H. Aghvami. Two dimensional pilot assisted channel estimation for turbo-coded ofdm systems. 1999.
[67] L. L. Scharf. Statistical signal processing: detection, estimation, and time series analgsis.
Addison-Wesley, 1991.
[68] M. Siala and E. Jaffrot. Semi-blind maximum a posteriori fast fading channel estimation for multicarrier systems. In GRETSI'99, Vannes, France, Sep. 1999.
[69] D. L. Snyder and M. I. Miller. Random processes in time and space. Springer-Verlag, New York, 1991.
[70] G. L. Stüber and M. Russel. Terrestrial digital video broadcasting for mobile reception using ofdm. In Globecom'95, pages 2049-2053, Singapore, Nov. 1995.
[71] F. Tufvesson and T. Maseng. Pilot assisted channel estimation for ofdm in mobile cellular systems. IEEE, 1997.
[72] S. B. Weinstein and P. M. Ebert. Data transmission by frequency-division multiplexing using the discrete fourier transform. IEEE Trans. on Commun. Tech., COM-19(5) :628-634, Oct. 1971.
[73] C. F. Wu. On the convergence properties of the em algorithm. Ann. Stat., 11(1) :95-103, 1983.
[74] L. J. Cimini Y. Li and N. R. Sollenberger. Robust channel estimation for ofdm systems with rapid dispersive fading channels. IEEE, 1998.
[75] N. Seshadri Y. Li and S. Ariyavisitakul. Channel estimation for ofdm systems with transmitter diversity in mobile wireless channels. IEEE Journ. on Select. Areas in Commun., 17(3), Mar. 1999.
[76] B. Yang, K. B. Letaief, R. S. Cheng, and Z. Cao. Robust and improved channel estimation for ofdm systems in frequency selective fading channels. In Global Telecom. Conf. GLOBECOM'99, pages 2499-2503. IEEE, 1999.
[77] B. Yang, K. B. Letaief, R. S. Cheng, and Z. Cao. Windowed dft based pilot-symbol-aided channel estimation for ofdm systems in multipath fading channels. In Vehicular Tech. Conf. IEEE, 2000.
[78] S. M. Zabin and H. V. Poor. Efficient estimation of class a noise parameters via the em algorithm. IEEE Trans. Inform. Theory, 37:60-72, Jan. 1991.
[79] Y. Zhao and A. Huang. A novel channel estimation method for ofdm mobile communication systems based on pilot signals and transform-domain processing. IEEE, 1997.

Table of content

Liste des notations - 8
Introduction générale - 12
1 Systéme et modéles - 15
Introduction - 15
1.1 Principe et modèles des systèmes OFDM - 16
1.1.1 Historique - principe - 16
1.1.2 Modélisation des systèmes OFDM - 17
Modèle analogique - 18
Passage au modèle numérique - 22
Interprétation temps-fréquence - 23
1.2 Modélisation de la chaine étudiée - 24
1.2.1 Caractéristiques du signal transmis - 24
1.2.2 Modélisation du signal reQu - 26
1.2.3 Caractéristiques du canal de propagation - 28
1.2.4 Représentation du canal de propagation - 31
1.3 Simplification de la représentation du canal - 32
1.4 Conclusion - 34
2 Estimation de canal semi-aveugle au sens du Maximum a Posteriori - 35
2.1 Introduction - 35
2.2 Etat de Part - 36
2.2.1 Introduction - 36
2.2.2 Estimateurs de la phase du canal - 38

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