Copyright © 2008 The Institute of Electronics, Information and Communication Engineers
Regular Section -- Papers -- Wireless Communication Technologies |
Model Based Prediction of Uplink Multi-Path Fading Channel Response for Pre-Equalization in Mobile MC-CDMA Systems
1 The authors are with Communications Laboratory, Graduate School of Engineering, Mie University, Tsu-shi, 514-8507 Japan. E-mail: kobayashi{at}mie-u.ac.jp
Multi-carrier code division multiple access (MC-CDMA) has been considered as one of the promising techniques for the next generation of mobile communication systems because of its efficient bandwidth usage, robustness to the multi-path fading and simple channel-sharing scheme. However, MC-CDMA cannot be employed in the uplink communication where the transmitted signal from each user propagates through the different multi-path fading channel, and the received signals are no longer orthogonal at the base station. As a result, bit error rate (BER) performance in the uplink MC-CDMA communication would be strongly degraded due to the occurrence of multi-user interference (MUI). To solve the MUI problem in the uplink MC-CDMA, the pre-equalization method was proposed in which the uplink signal is pre-equalized at the user terminal by using the channel response estimated from the downlink. Although the pre-equalization method is very effective for the stationary uplink channel with fixed users, it is hard to be employed in the time varying fading channel with mobile users, because there is a big difference in the channel responses between downlink and uplink. For the efficient MUI compensation, each user terminal would be required to predict the future channel conditions based on the current observation. This paper proposes a method for model based uplink channel response prediction by employing the spectral decomposition of the downlink channel impulse response. Computer simulation results show that the proposed method can achieve the accurate prediction of channel response for mobile users during the uplink transmission and allows the effective MUI compensation.
Key Words: MC-CDMA, pre-equalization, multi-path fading channel, model-based prediction method, ML estimation
Manuscript received December 16, 2005. Manuscript revised November 28, 2006.
Reference
[1] S. Weinstein and P. Ebert, "Data transmission by frequency-division multiplexing using the discrete Fourier transform," IEEE Trans. Commun. Technol., vol.19, no.5, pp.628–634, Oct. 1971. [2] N. Yee, J.-P. Linnartz, and G. Fettweis, "Multicarrier CDMA in indoor wireless radio networks," Proc. PIMRC'93, pp.109–113, Yokohama, Sept. 1993. [3] S. Hara and R. Prasad, "Overview of multicarrier CDMA," IEEE Commun. Mag., vol.35, no.12, pp.126–133, Dec. 1997. [4] M. Hafez, Z. Li, and M. Aho, "Evaluation of uplink and downlink MC-CDMA receivers in generalized fading channels," IEICE Trans. Commun., vol.E87-B, no.1, pp.88–96, Jan. 2004. [5] Y. Zeng and Q. Yin, "Direct decoder of uplink space-time block coded MC-CDMA systems," IEICE Trans. Commun., vol.E88-B, no.2, pp.452–462, Feb. 2005. [6] H. Tomeba, S. Takaoka, and F. Adachi, "Frequency domain pre-equalization transmit diversity for MC-CDMA uplink transmission," IEICE Trans. Commun., vol.E88-B, no.2, pp.575–584, Feb. 2005. [7] S. Nobilet and J. Helard, "A pre-equalization technique for uplink MC-CDMA systems using TDD and FDD modes," Proc. VTC 2002-Fall, vol.1, pp.346–350, Sept. 2002. [8] D. Mottier and D. Castelain, "SINR-based channel pre-equalization for uplink multi-carrier CDMA systems," Proc. 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, vol.4, pp.1488–1492, Sept. 2002. [9] A. Goldsmith, Wireless Communications, Cambridge University Press, 2005. [10] Y.G. Li and L.J. Cimini, "Bounds on the inter-channel interference of OFDM in time-varying impairments," IEEE Trans. Commun., vol.49, no.3, pp.401–404, March 2001. [11] S. Campbell and C. Meyer, Generalized Inverses of Linear Transformations, Dover Publications, 1991. [12] S. Haykin, Adaptive filter theory, Prentice Hall, 2001. [13] S. Takaoka and F. Adachi, "Pilot-aided adaptive prediction channel estimation in a frequency-nonselective fading channel," IEICE Trans. Commun., vol.E85-B, no.8, pp.1552–1560, Aug. 2002. [14] J. Joo, "Linear prediction based channel estimation using pilot and traffic channels in multi-code CDMA systems," IEICE Trans. Commun., vol.E86-B, no.12, pp.3551–3558, Dec. 2003. [15] H. Gazzah, "Revisiting the linear prediction algorithm for blind channel equalization and identification," Proc. IEEE International Conference on Acoustics, Speech, and Signal Processing, vol.4, pp.865–868, May 2004. [16] S. Takaoka and F. Adachi, "Frequency-domain adaptive prediction iterative channel estimation for OFDM signal reception," IEICE Trans. Commun., vol.E88-B, no.4, pp.1730–1734, April 2005. [17] W. Jakes, Microwave mobile communications, Wiley-IEEE Press; 2Rev Ed edition, 1994. [18] G. Park, D. Hong, and Ch. Kang, "A new Doppler spread estimation using FFT," IEICE Trans. Commun., vol.E86-B, no.9, pp.2799–2803, Sept. 2003. [19] Y. Ch. KO, "Doppler spread estimation in mobile communication systems," IEICE Trans. Commun., vol.E88-B, no.2, pp.724–728, Feb. 2005. [20] G. Mkrtchyan, K. Naito, K. Mori, and H. Kobayashi, "Maximum Doppler frequency spread estimation method using mean square derivative of the ML time domain estimated channel impulse response for OFDM systems," IEICE Technical Report, SAT2005-42, pp.161–166, Oct. 2005. [21] S. Abe, S. Takaoka, and F. Adachi, "Frequency domain transmit equalization for uplink MC-CDMA," IEICE Technical Report, RCS2003-375, pp.131–136, March 2004.
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