International Journal of Information Technology and Computer Science(IJITCS)

ISSN: 2074-9007 (Print), ISSN: 2074-9015 (Online)

Published By: MECS Press

IJITCS Vol.6, No.5, Apr. 2014

Six Algorithms for Frequency Offset Estimation in OFDM Systems

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Ahmed M. Alaa

Index Terms

Orthogonal Frequency Division Multiplexing (OFDM), Carrier Frequency Offset (CFO), Frequency Offset Estimation, Frequency Synchronization, Baseband Processing


Generally, wireless systems suffer from Carrier Frequency Offsets (CFO), which results either from the receiver’s oscillator’s impairments or Doppler shifts. The frequency offset between transmitter and receiver local oscillator is a main drawback of OFDM systems. A frequency drift in the receiver’s oscillator would result in a frequency offset in the received signal, this offset consists of two parts: a Fine offset, as a fraction of OFDM subcarrier spacing, and a Coarse offset that is equal to an integer multiple of the subcarrier spacing. Coarse offsets results in two problems; firstly, the modulation symbols are located on the wrong frequency bins, secondly, the pilots used for channel estimation are misplaced leading to a faulty channel estimate and severe signal distortion by the Equalizer. Fine Offsets result in a loss of orthogonality and thus ICI (Inter-Carrier Interference), as the frequency bin of a certain modulation symbol would contain some information about the neighboring symbol bin.

Cite This Paper

Ahmed M. Alaa,"Six Algorithms for Frequency Offset Estimation in OFDM Systems", International Journal of Information Technology and Computer Science(IJITCS), vol.6, no.5, pp.36-42, 2014. DOI: 10.5815/ijitcs.2014.05.05


[1]T. Pollet, M. van Bladel, and M. Moeneclaey, `BER sensitivity of OFDM systems to carrier frequency offset and Wiener phase noise', IEEE Transactions on Communications, vol. 43, no. 2/3/4, pp. 191-193, February/March/April 1995. 

[2]Shiou-Hong Chen, Way-Hong He, Hou-Shin Chen, Yumin Lee, ‘Mode Detection, Synchronization, and Channel Estimation for DVB-T OFDM Receiver’, GLOBECOM 2003, IEEE, 2003

[3]J.A.C. Bingham, `Multicarrier modulation for data transmission: An idea whose time has come', IEEE Communications Magazine, vol. 28, no. 5, pp. 5-14, May 1990.

[4]Z. Cvetkovic, V. Tarokh, S. Yoon, “On frequency offset estimation in OFDM”, IEEE Transactions on Wireless Communications, Vol. 12, no. 3, pp. 1062 – 1072, March 2013.

[5]D. Zhang, L. Yu, P. Zhou, and Q. Huang, “A High Performance Frequency Offset Estimation Method for OFDM”, Third International Conference on Intelligent System Design and Engineering Applications (ISDEA), Hong Kong, pp. 73 – 76, Jan. 2013 

[6]X. Chai, Z. Zhang, X. Zhang , and K. Long, “Efficient carrier frequency offset estimation for OFDM using periodic training sequences”, Wireless and Optical Communication Conference (WOCC), Chongqing, 16-18 May 2013

[7]L. Danping, Li Yongzhao, H. Zhang , L. J. Cimini, “Integer Frequency Offset Estimation for OFDM Systems With Residual Timing Offset Over Frequency Selective Fading Channels”, IEEE Transactions on Vehicular Technology, Vol. 61 , No. 6, July 2012.