Modal analysis/filtering to estimate time-varying MIMO-OFDM channels

In the multipatb multiple-input multiple-output (MIMO) channel, long-term/large-scale properties (e.g., delays, angles, powers) remain approximately constant over many coherence times (i.e., over many Doppler periods) and define the structural terms of the propagation channel referred as delay (powers and delays) and angular (powers and angles of departure and arrival) modes of the channel. Effective improvement of the channel estimate is obtained by estimating delay and angular modal spaces via modal analysis and by filtering the (original) least squares channel estimates as projection onto the modal spaces. The paper also provides experimental validation of the overall method with realistic channel models

[1]  Umberto Spagnolini,et al.  Reduced rank channel estimation and rank order selection for CDMA systems , 2001, ICC 2001. IEEE International Conference on Communications. Conference Record (Cat. No.01CH37240).

[2]  Umberto Spagnolini,et al.  Multi-slot estimation of space-time channels , 2002, 2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333).

[3]  John M. Cioffi,et al.  Spatio-temporal coding for wireless communication , 1998, IEEE Trans. Commun..

[4]  Ye Li,et al.  MIMO-OFDM channel estimation based on subspace tracking , 2003, The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring..

[5]  Marc Moonen,et al.  Optimal training design for MIMO OFDM systems in mobile wireless channels , 2003, IEEE Trans. Signal Process..

[6]  Arogyaswami Paulraj,et al.  Joint angle and delay estimation using shift-invariance techniques , 1998, IEEE Trans. Signal Process..

[7]  Ye Li.  Optimum training sequences for OFDM systems with multiple transmit antennas , 2000, Globecom '00 - IEEE. Global Telecommunications Conference. Conference Record (Cat. No.00CH37137).

[8]  S.K. Wilson,et al.  On channel estimation in OFDM systems , 1995, 1995 IEEE 45th Vehicular Technology Conference. Countdown to the Wireless Twenty-First Century.

[9]  Frederick W. Vook,et al.  Broadband MIMO-OFDM channel estimation via near-maximum likelihood Time Of Arrival estimation , 2002, 2002 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[10]  Zhigang Cao,et al.  Channel estimation for OFDM transmission in multipath fading channels based on parametric channel modeling , 2001, IEEE Trans. Commun..

[11]  Umberto Spagnolini,et al.  Pilot-based channel estimation for OFDM systems by tracking the delay-subspace , 2004, IEEE Transactions on Wireless Communications.

[12]  Gerhard Fettweis,et al.  MIMO channel estimation with dimension reduction , 2002, The 5th International Symposium on Wireless Personal Multimedia Communications.