New Iterative Method for Estimation of Carrier Frequency in Multicarrier Systems

Ramadhan Masmoudi

Ramadhan Masmoudi Laboratory of Sustainable Development and Computer Science (L.D.D.I), Department of Hydrocarbons and Renewable Energies,Ahmed Draia University - Adrar (Algeria).

Keywords: CFO, OFDM, SB, MC, DFT

Abstract

The key problem for OFDM (Orthogonal Frequency Division Multiple) systems is who to Estimate carrier frequency offset (CFO) with reduced complexity and acceptable performance. The CFO must be compensated before DFT (Discrete Fourier Transform) in order to restore data correctly
and enhance the system performance. This paper, present a low complexity estimator of CFO with Semi-Blind (SB) criterion based on pilot tones and on virtual subcarriers, and with the aid of subspace based method. However, MUSIC and ESPRIT based semi-blind algorithms require a highly computational complexity. To overcome this drawback, we use Taylor’s series for the first order as developed in [1].
The present methods developed in this paper are very suitable for Multi- Carrier (MC) systems when the CFO are present. Simulation results demonstrated that the semi-blind (SB) approach outperforms the blind-based approach.

References

S. Attallah, “Blind Estimation of Residual Carrier Offset in OFDM Systems,” IEEE Trans. on Signal Processing, Vol. 11, No. 2, 2004.

M. Movahhedian, YiMa, and R. Tafazolli, “Blind CFO Estimation for Linearly Precoded OFDMA Uplink,” IEEE Trans. On Signal Processing, Vol. 58, No. 9, September 2010.

M. Morelli, and M. Moretti, “Joint Maximum Likelihood Estimation of CFO, Noise Power, and SNR in OFDM Systems,” IEEE Wireless Communications Letters, Vol. 2, No. 1, February 2013.

J. van de Beek, M. Sandell, and P. O. Borjesson, “ML estimation of time and frequency offset in OFDM systems,” IEEE Trans. Signal Processing, vol. 45, pp. 1800–1805, July 1997.

H. Lui and U. Tureli, “A high efficiency carrier estimator for OFDM communications,” IEEE Commun. Lett., vol. 2, pp. 104–106, Apr. 1998.

U. Tureli, H. Liu, and M. D. Zoltowski, “OFDM blind carrier offset estimation: ESPRIT,” IEEE Trans. Commun., vol. 48, pp. 1459–1461, Sept. 2000.

B. Chen and H. Wang, “Blind Estimation of OFDM carrier frequency offset via oversampling,” IEEE Trans. on Signal Processing, Vol. 52, No. 7, pp. 2047-2057, July 2004

S. Attallah and H. Fu, “Joint channel and carrier offset estimation in multiuser CDMA system,” IEEE Commun. Lett., vol. 6, pp. 428–430, Oct. 2002.

YanWu, S. Attallah, and J. W. M. Bergmans, “On the Optimality of the Null Subcarrier Placement for Blind Carrier Offset Estimation in OFDM Systems,” IEEE Trans On Vehicular Technology, Vol. 58, No. 4, May 2009.

M. Ghogho, A. Swami, and G. Giannakis, “Optimized null-subcarrier selection for CFO estimation in OFDM over frequency-selective fading channels,” in Proc. IEEE GLOBECOM, Nov. 2001, vol. 1, pp. 202–206.

M. Ghogho and A. Swami, “Semi-blind frequency offset synchronization for OFDM,” presented at the IEEE Int. Conf. Acoustics, Speech, Signal Processing (ICASSP), Orlando, FL, May 2002

S. Attallah, Y. Wu, and J. W. M. Bergmans, “Low complexity blind es- timation of residual carrier offset in orthogonal frequency division multi-plexing based,” IET Communications, vol. 1, no. 4, pp. 604{611, August 2007.