Abstract
Three pilot symbol architectures are compared in an orthogonal frequency-division multiplexing (OFDM) system for a down link diversity environment. The first architecture is called a basic pilot scheme, in which two long pilot symbols (similar to 802.11a) are transmitted on interleaved sub-carriers from Q transmit antennas. The second architecture extends the basic scheme by interleaving the two pilot symbols in the time domain as well as the frequency domain. Each pilot symbol is preceded with a single cyclic prefix (CP) of length 800 ns. The third architecture interleaves a single pilot symbol with a CP of length 1600 ns, over twice the number of sub-carriers than the two preceding architectures. The modified architectures always outperform the basic pilot scheme in HIPERLAN/2 channel environment, since they reduce the interpolation error. No additional pilot overhead (compared to 802.11a) is necessary if the diversity order is low (≤2) and the maximum excess delay of a channel is confined to a CP of length 800 ns.
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References
IEEE Std 802.11a/D7.0, “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: High-Speed Physical Layer in the 5 GHz Band”, New York, USA, 1999.
http://standards.ieee.org/announcements/pr_p80211n.html
Y.G. Li, N. Seshadri, and S. Ariyavisitakul, “Channel Estimation for OFDM Systems with Transmitter Diversity in Mobile Wireless Channels”, IEEE Journal on Selected Areas in Communication, Vol. 17, No. 3, pp. 461–471, 1999.
A.N. Mody and G.L. Stüber, “Parameter Estimation for OFDM with Transmit Receive Diversity”, in Proceedings of the 53rd IEEE VTC, Rhodes, Greece, pp. 820–824, 2001.
E.G. Larsson and J. Li, “Preamble Design for Multiple-Antenna OFDM-based WLANs with Null Subcarriers”, IEEE Signal Processing Letters, Vol. 8, No. 11, pp. 285–288, 2001.
I. Tolochko and M. Faulkner, “Real Time LMMSE Channel Estimation for Wireless OFDM Systems with Transmitter Diversity”, in Proceedings of the 56th IEEE VTC, Vancouver, Canada, pp. 1555–1559, 2002.
J. Medbo and P. Schramm, “Channel Models for HIPERLAN/2 in Different Indoor Scenarios”, ETSI BRAN doc. No. 3ER1085B, 1998.
J.L. Seoane, S.K. Wilson, and S. Gelfand, “Analysis of Intertone and Interblock Interference in OFDM when the Length of the Cyclic Prefix is Shorter than the Length of the Impulse Response of the Channel”, in Proceedings of the IEEE GLOBECOM, Vol. 1, pp. 32–36, 1997.
M. Faulkner, “The Effect of Filtering on the Performance of OFDM Systems”, IEEE Transactions on Vehicular Technology, Vol. 49, No. 5, pp. 1877–1884, 2000.
O. Edfors, M. Sandell, J.-J. van de Beek, S.K. Wilson, and P.O. Börjesson, “Analysis of DFT-Based Channel Estimators for OFDM”, Journal of Wireless Personal Communication, Vol. 12, No. 1, pp. 55–70, 2000.
R. van Nee and R. Prasad, OFDM for Wireless Multimedia Communications, Artech House, USA, 2000.
O. Edfors, M. Sandell, J.J. van de Beek, S.K. Wilson, and P.O. Börjesson, “OFDM Channel Estimation by Singular Value Decomposition”, IEEE Transaction on Communication, Vol. 46, No. 7, pp. 931–939, 1998.
L.L. Scharf, Statistical Signal Processing: Detection, Estimation, and Time Series Analysis, Addison-Wesley, Inc., USA, 1991.
A. Doufexi, S. Armour, M. Butler, A. Nix, and D. Bull, “A Study of the Performance of HIPERLAN/2 and IEEE 802.11a Physical Layers”, in Proceedings of the IEEE VTC, Rhodes, Greece, pp. 668–672, 2001.
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Tolochko, I., Faulkner, M. Channel Estimation in Wireless LANs with Transmitter Diversity. Wireless Pers Commun 31, 63–75 (2004). https://doi.org/10.1007/s11277-004-1636-5
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DOI: https://doi.org/10.1007/s11277-004-1636-5