Exact Signal Model and New Carrier Frequency Offset Compensation Scheme for OFDM

Carrier frequency offset (CFO) causes spectrum misalignment of transmitter and receiver filters. This misalignment leads to energy loss and distortion of received signal, resulting in performance degradation of the whole system. However, these issues are often overlooked by existing works. This paper presents an exact signal model for OFDM that takes into account the CFO-induced spectral misalignment and related aliasing effects. Incorporating these practical issues, we also propose a new preamble structure and a new CFO compensation approach to mitigate their negative effects. Theoretical analysis and simulation results substantiate the importance of the exact signal model and the advantage of the proposed CFO compensation scheme.

[1]  Leonard J. Cimini,et al.  Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing , 1985, IEEE Trans. Commun..

[2]  Marc Moeneclaey,et al.  BER sensitivity of OFDM systems to carrier frequency offset and Wiener phase noise , 1995, IEEE Trans. Commun..

[3]  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).

[4]  Marco Luise,et al.  Carrier frequency acquisition and tracking for OFDM systems , 1996, IEEE Trans. Commun..

[5]  Norman C. Beaulieu,et al.  Reduced ICI in OFDM systems using the "better than" raised-cosine pulse , 2004, IEEE Communications Letters.

[6]  Gang Lin,et al.  Optimal Pulses Robust to Carrier Frequency Offset for OFDM/QAM Systems , 2008, IEEE Communications Letters.

[7]  Hui Liu,et al.  Frequency offset and I/Q imbalance compensation for direct-conversion receivers , 2005, IEEE Transactions on Wireless Communications.

[8]  Hlaing Minn,et al.  Optimal training signals for MIMO OFDM channel estimation in the presence of frequency offset and phase noise , 2006, IEEE Transactions on Communications.

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

[10]  Per Ola Börjesson,et al.  ML estimation of time and frequency offset in OFDM systems , 1997, IEEE Trans. Signal Process..

[11]  Hlaing Minn,et al.  Optimal training signals for MIMO OFDM channel estimation , 2004, IEEE Global Telecommunications Conference, 2004. GLOBECOM '04..

[12]  Paul H. Moose,et al.  A technique for orthogonal frequency division multiplexing frequency offset correction , 1994, IEEE Trans. Commun..

[13]  Hai Lin,et al.  Subcarrier allocation based compensation for carrier frequency offset and I/Q imbalances in OFDM systems , 2009, IEEE Transactions on Wireless Communications.

[14]  Heinrich Meyr,et al.  Optimum receiver design for wireless broad-band systems using OFDM. I , 1999, IEEE Trans. Commun..

[15]  Heidi Steendam,et al.  The true Cramer-Rao bound for carrier frequency estimation from a PSK signal , 2004, IEEE Transactions on Communications.