Optimal Pilots for Frequency Offset and Channel Estimation in OFDMA Uplink

Optimal pilots design and placement for the frequency offset and channel estimation in orthogonal frequency- division multiplexing access (OFDMA) uplink systems are proposed. The received pilots of multiple users can always be demodulated, even if they are totally overlapped due to the large frequency offsets. With the knowledge of channel state information (CSI) at the receiver, the performance of the proposed frequency offset estimation is robust to the channel estimation errors. The frequency offset and CSI can be jointly estimated by employing the proposed pilots.

[1]  Sergio Barbarossa,et al.  Channel-independent synchronization of orthogonal frequency division multiple access systems , 2002, IEEE J. Sel. Areas Commun..

[2]  Jong-Ho Lee,et al.  Time and Frequency Synchronization for OFDMA Uplink System using the SAGE Algorithm , 2007, IEEE Transactions on Wireless Communications.

[3]  Yu-Dong Yao,et al.  Deterministic multiuser carrier-frequency offset estimation for interleaved OFDMA uplink , 2004, IEEE Transactions on Communications.

[4]  Per Ödling,et al.  A time and frequency synchronization scheme for multiuser OFDM , 1999, IEEE J. Sel. Areas Commun..

[5]  Vijay K. Bhargava,et al.  Optimal periodic training signal for frequency offset estimation in frequency selective fading channels , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[6]  Wei Zhang,et al.  MIMO-OFDM Channel Estimation in Presence of Carrier Frequency Offsets , 2007, IEEE GLOBECOM 2007 - IEEE Global Telecommunications Conference.

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

[8]  Hlaing Minn,et al.  CTH01-4: Two Novel Iterative Joint Frequency-Offset and Channel Estimation Methods for OFDMA Uplink , 2006, IEEE Globecom 2006.

[9]  H. Bolcskei.  Blind high-resolution uplink synchronization of OFDM-based multiple access schemes , 1999, 1999 2nd IEEE Workshop on Signal Processing Advances in Wireless Communications (Cat. No.99EX304).

[10]  Hlaing Minn,et al.  Two novel iterative joint frequency-offset and channel estimation methods for OFDMA uplink , 2006, IEEE Transactions on Communications.

[11]  C.-C. Jay Kuo,et al.  Synchronization Techniques for Orthogonal Frequency Division Multiple Access (OFDMA): A Tutorial Review , 2007, Proceedings of the IEEE.

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