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Optimal Power Allocation for Channel Estimation of OFDM Uplinks in Time-Varying Channels

  • Yao, Rugui (School of Electronics and Information, Northwestern Polytechnical University) ;
  • Liu, Yinsheng (Institute of Broadband Wireless Mobile Communications & the State Key Laboratory of Rail Traffic Control and Safety) ;
  • Li, Geng (School of Electronics and Information, Northwestern Polytechnical University) ;
  • Xu, Juan (School of Electronic and Control Engineering, Chang'an University)
  • Received : 2014.06.25
  • Accepted : 2014.09.11
  • Published : 2015.02.01

Abstract

This paper deals with optimal power allocation for channel estimation of orthogonal frequency-division multiplexing uplinks in time-varying channels. In the existing literature, the estimation of time-varying channel response in an uplink environment can be accomplished by estimating the corresponding channel parameters. Accordingly, the optimal power allocation studied in the literature has been in terms of minimizing the mean square error of the channel estimation. However, the final goal for channel estimation is to enable the application of coherent detection, which usually means high spectral efficiency. Therefore, it is more meaningful to optimize the power allocation in terms of capacity. In this paper, we investigate capacity with imperfect channel estimation. By exploiting the derived capacity expression, an optimal power allocation strategy is developed. With this developed power allocation strategy, improved performance can be observed, as demonstrated by the numerical results.

Keywords

References

  1. J.A.C. Bingham, "Multicarrier Modulation for Data Transmission: An Idea Whose Time Has Come," IEEE Commun. Mag., vol. 28, no. 5, May 1990, pp. 5-14. https://doi.org/10.1109/35.54342
  2. T. May, H. Rohling, and V. Engels, "Performance Analysis of Viterbi Decoding for 64-DAPSK and 64-QAM Modulated OFDM Signals," IEEE Trans. Commun., vol. 46, no. 2, Feb. 1998, pp. 182-190. https://doi.org/10.1109/26.659477
  3. Y. Li, "Pilot-Symbol-Aided Channel Estimation for OFDM in Wireless Systems," IEEE Trans. Veh. Technol., vol. 49, no. 4, July 2000, pp. 1207-1215. https://doi.org/10.1109/25.875230
  4. M.J.F.-G. Garcia, S. Zazo, and J.M. Paez-Borrallo, "Pilot Patterns for Channel Estimation in OFDM," Electron. Lett., vol. 36, no. 12, June 2000, pp. 1049-1050. https://doi.org/10.1049/el:20000714
  5. J.W. Choi and Y.-H. Lee, "Optimum Pilot Pattern for Channel Estimation in OFDM Systems," IEEE Trans. Wireless Commun., vol. 4, no. 5, Sept. 2005, pp. 2083-2088. https://doi.org/10.1109/TWC.2005.853891
  6. K.F. Lee and D.B. Williams, "Pilot-Symbol-Assisted Channel Estimation for Space-Time Coded OFDM Systems," EURASIP J. Adv. Signal Process., vol. 2002, no. 1, May 2002, pp. 507-516. https://doi.org/10.1155/S111086570200080X
  7. S. Coleri et al., "Channel Estimation Techniques Based on Pilot Arrangement in OFDM Systems," IEEE Trans. Broadcast., vol. 48, no. 3, Sept. 2002, pp. 223-229. https://doi.org/10.1109/TBC.2002.804034
  8. S. Ohno and G.B. Giannakis, "Capacity Maximizing MMSEOptimal Pilots for Wireless OFDM over Frequency-Selective Block Rayleigh-Fading Channels," IEEE Trans. Inf. Theory, vol. 50, no. 9, Sept. 2004, pp. 2138-2145. https://doi.org/10.1109/TIT.2004.833365
  9. M. Visintin, "Karhunen-Loeve Expansion of a Fast Rayleigh Fading Process," Electron. Lett., vol. 32, no. 18, Aug. 1996, pp. 1712-1713. https://doi.org/10.1049/el:19961128
  10. T. Zemen and C.F. Mecklenbrauker, "Time-Varaint Channel Estimation Using Discrete Prolate Spheroidal Sequences," IEEE Trans. Signal Process., vol. 53, no. 9, Sept. 2005, pp. 3597-3607. https://doi.org/10.1109/TSP.2005.853104
  11. Z. Tang et al., "Pilot-Assisted Time-Varying Channel Estimation for OFDM Systems," IEEE Trans. Signal Process., vol. 55, no. 5, May 2007, pp. 2226-2238. https://doi.org/10.1109/TSP.2007.893198
  12. K.D. Teo and S. Ohno, "Optimal MMSE Finite Parameter Model for Doubly-Selective Channels," IEEE Global Telecommun., St. Louis, MO, USA, Nov. 28-Dec. 2, 2005, pp. 3503-3507.
  13. S. Haykin, "Adaptive Filter Theory," Engewood Cliffs, NJ, USA: Prentice-Hall, 1996, pp. 610-620.
  14. F. Hlawatsch and G. Matz, "Wireless Communication over Rapidly Time-Varying Channels," Burlington, VT, USA: Academic Press of Elsevier, 2011, pp. 40-48.
  15. Z. Du et al., "Maximum Likelihood Based Channel Estimation for Macrocellular OFDM Uplinks in Dispersive Time-Varying Channels," IEEE Trans. Wireless Commun., vol. 10, no. 1, Jan. 2011, pp. 176-187. https://doi.org/10.1109/TWC.2010.110910.100135
  16. Y. Liu et al., "Channel Estimation for Macrocellular OFDM Uplinks in Time-Varying Channels," IEEE Trans. Veh. Technol., vol. 61, no. 4, May 2012, pp. 1709-1718. https://doi.org/10.1109/TVT.2012.2187939
  17. R. Yao et al., "On Channel Estimation for OFDM Uplinks in Time-Varying Channels," to appear in IET Commun., 2015.
  18. H. Huang, "Spatial Channel Model for Multiple Input Multiple Output (MIMO) Simulations," 3GPP TSG RAN, Edinburgh, UK, Tech. Rep. 3GPP TR 25.996(12.0.0)-12, Sept. 2014.
  19. A. Gorokhov and J.-P. Linnartz, "Robust OFDM Receivers for Dispersive Time-Varying Channels: Equalization and Channel Acquisition," IEEE Trans. Commun., vol. 52, no. 4, Apr. 2004, pp. 572-583. https://doi.org/10.1109/TCOMM.2004.826354
  20. A. Scaglione, S. Babarossa, and G.B. Giannakis, "Self- Recovering Equalization of Time-Selective Fading Channels Using Redundant Filterbank Proceders," in Proc. DSP Workshop, Bryce Canyon, UT, USA, Sept. 1998.
  21. A. Goldsmith, "Wireless Communications," Cambridge, UK: Cambridge University Press, 2005, pp. 65, 303-308, 358-366.
  22. D. Tse and P. Viswanath, "Fundamentals of Wireless Communication," Cambridge, UK: Cambridge University Press, 2005, pp. 332-382.
  23. T. Yoo and A. Goldsmith, "Capacity and Power Allocation for Fading MIMO Channels with Channel Estimation Error," IEEE Trans. Inf. Theory, vol. 52, no. 5, May 2006, pp. 2203-2214. https://doi.org/10.1109/TIT.2006.872984
  24. A. Jeffrey and D. Zwillinger, "Table of Integrals, Series, and Products," 7th Edition, Amsterdam, Netherlands: Elsevier Academic Press, 2007, pp. 1-23.