S. Asoodeh and A. Rezazade (Iran)
The model which is considered here for the OFDM is shown in Fig 1.Orthogonal frequency division multiplexing, carrier frequency offset estimation. ε mX mx nr mY AWGN
)1( )sin( )sin(ˆ − = N N j mm e N N XX ε π πε πε (3)Orthogonal frequency division multiplexing (OFDM) is being in use for digital audio broadcasting and television systems. One of the important specifications of this method of division multiplexing is its sensitivity to the carrier frequency offset (CFO). Frequency offset in OFDM systems leads to loss of orthogonality among sub carriers, and will result in the occurrence of inter-carrier interference. A novel algorithm based on Discrete Fourier transform (DFT) is presented in this paper, for CFO estimation with higher precision in compare with other methods proposed before. The performance of this algorithm is dependent on the number of point of DFT, which will be discussed in this paper. )))(1((1 0 ) )( sin( ))(sin( ε π επ επ +−−− ≠ = ∑ +− +− = mkN N jN mk k km e N mk N mk XI (4) where denotes the transmitted symbol for the mth sub-carrier, is that its amplitude and phase are affected by frequency offset and the other component is created by effect of other sub-carriers on related sub carrier which is called inter-carrier interference (ICI). mX mXˆ mX
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