Inter-carrier interference cancellation method based on cyclic embedding for OFDM communication systems

Abstract

For orthogonal frequency-division multiplexing (OFDM) communication systems, the frequency offsets in mobile radio channels distort the orthogonality between subcarriers, resulting in inter-carrier interference (ICI), which seriously degrades the performance of systems. Based on ICI coefficients analysis and reasonable estimation of the frequency offset, the paper presents a novel decorrelation interference cancellation method with the use of frequency-domain equalization at the receiver. Without the iterative operation on the weighting coefficients and the inverse operation on the matrix, ICI can be eliminated by directly using the cyclic embedding algorithm of the Toeplitz matrix in terms of the discrete Fourier transform (DFT). Compared with conventional frequency-domain equalization, this new scheme has better convergence reliability and lower computational complexity. Simulation results show that an OFDM system using the proposed ICI cancellation scheme can effectively eliminate ICI, have significant performance improvement and mitigate the effects of OFDM communication systems. The scheme works very well in the multipath radio channel and high-speed mobile environment.