EM-based Joint ML Estimation of Carrier Frequency Offset and Channel Coefficients in MIMO-OFDM Systems

In this paper, we propose a new scheme for joint maximum- likelihood (ML) estimation of carrier-frequency offset (CFO) and channel coefficients in multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. To reduce the prohibitive computational complexity of joint ML estimation problems, the expectation- maximization (EM) algorithm is employed. Moreover, the Cramer-Rao bounds (CRB) for both CFO and channel estimators are developed to evaluate the performance of the proposed scheme. Computer simulations show that the proposed algorithm achieves almost ideal performance compared with the CRB for both channel and frequency offset estimations.

[1]  Costas N. Georghiades,et al.  Sequence estimation in the presence of random parameters via the EM algorithm , 1997, IEEE Trans. Commun..

[2]  Xiaodong Wang,et al.  LDPC-based space-time coded OFDM systems over correlated fading channels: performance analysis and receiver design , 2001, Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252).

[3]  Jong-Ho Lee,et al.  Joint carrier frequency synchronization and channel estimation for OFDM systems via the EM algorithm , 2006, IEEE Transactions on Vehicular Technology.

[4]  P. Priotti.  Frequency synchronization of MIMO OFDM systems with frequency-selective weighting , 2004, 2004 IEEE 59th Vehicular Technology Conference. VTC 2004-Spring (IEEE Cat. No.04CH37514).

[5]  Marc Engels.  Wireless OFDM Systems: How to Make Them Work? , 2002 .

[6]  Stuart C. Schwartz,et al.  Joint frequency offset and channel estimation for OFDM , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[7]  T.C.W. Schenk,et al.  Frequency synchronization for MIMO OFDM wireless LAN systems , 2003, 2003 IEEE 58th Vehicular Technology Conference. VTC 2003-Fall (IEEE Cat. No.03CH37484).

[8]  Ehud Weinstein,et al.  Parameter estimation of superimposed signals using the EM algorithm , 1988, IEEE Trans. Acoust. Speech Signal Process..

[9]  Ben Lu,et al.  Bayesian blind turbo receiver for coded OFDM systems with frequency offset and frequency-selective fading , 2002, 2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333).

[10]  C.-C. Jay Kuo,et al.  Maximum-likelihood synchronization and channel estimation for OFDMA uplink transmissions , 2006, IEEE Transactions on Communications.

[11]  Helmut Bölcskei,et al.  On the capacity of OFDM-based spatial multiplexing systems , 2002, IEEE Trans. Commun..

[12]  Klaus I. Pedersen,et al.  Channel parameter estimation in mobile radio environments using the SAGE algorithm , 1999, IEEE J. Sel. Areas Commun..

[13]  Geoffrey Ye Li,et al.  Broadband MIMO-OFDM wireless communications , 2004, Proceedings of the IEEE.

[14]  Dong-Jo Park,et al.  Hopping pilots for estimation of frequency-offset and multiantenna channels in MIMO OFDM , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[15]  Xiaodong Wang,et al.  EM-based iterative receiver design with carrier-frequency offset estimation for MIMO OFDM systems , 2005, IEEE Transactions on Communications.

[16]  Umberto Mengali,et al.  Carrier-frequency estimation for transmissions over selective channels , 2000, IEEE Trans. Commun..

[17]  Petre Stoica,et al.  Training sequence design for frequency offset and frequency-selective channel estimation , 2003, IEEE Trans. Commun..

[18]  Zhu Han,et al.  A MIMO-OFDM channel estimation approach using time of arrivals , 2005, IEEE Transactions on Wireless Communications.

[19]  Hlaing Minn,et al.  Optimal training signals for MIMO OFDM channel estimation , 2006, IEEE Trans. Wirel. Commun..

[20]  C.-C. Jay Kuo,et al.  An EM-based joint maximum likelihood estimation of carrier frequency offset and channel for uplink OFDMA systems , 2004, IEEE 60th Vehicular Technology Conference, 2004. VTC2004-Fall. 2004.

[21]  T. Moon.  The expectation-maximization algorithm , 1996, IEEE Signal Process. Mag..

[22]  Marc Engels,et al.  Wireless OFDM Systems , 2002 .

[23]  Tao Cui,et al.  Robust joint frequency offset and channel estimation for OFDM systems , 2004, IEEE 60th Vehicular Technology Conference, 2004. VTC2004-Fall. 2004.

[24]  Geoffrey Ye Li,et al.  MIMO-OFDM for wireless communications: signal detection with enhanced channel estimation , 2002, IEEE Trans. Commun..

[25]  Yongzhe Xie,et al.  Two EM-type channel estimation algorithms for OFDM with transmitter diversity , 2002, 2002 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[26]  Ilan Ziskind,et al.  Maximum likelihood localization of multiple sources by alternating projection , 1988, IEEE Trans. Acoust. Speech Signal Process..