Abstract

A well-known problem of orthogonal frequency division multiplexing (OFDM) is its sensitivity to offset between the transmitted and received carrier frequencies. In OFDM communication systems, the frequency offsets in mobile radio channels deform the orthogonality between subcarriers which causes inter carrier interference (ICI). ICI causes power leakage among subcarriers and it further degrades the system performance. In this paper a novel bandwidth efficient method for combating the effects of ICI is presented. In the present scheme, the self cancellation mechanism is used to compress ICI signals without any equalization. At transmitter and receiver parallel Fast Fourier Transform (FFT) factorization is performed using Radix-2 decimation in frequency (DIF) FFT algorithm derived from the well known Cooley-turkey factorization. The proposed scheme cancels the ICI coefficient effectively and further improves system performance as shown through extensive simulations.

Key words: Orthogonal frequency division multiplexing (OFDM), intercarrier interference, carrier frequency offset, Radix2, fast Fourier transform (FFT).