Performance of ICI Cancellation in OFDM System Using Different Reduction Techniques

Orthogonal frequency division multiplexing (OFDM) is used in many wireless broadband communication systems because it is a simple and scalable solution to inter symbol interference caused by a multipath channel. OFDM is emerging as preferred modulation scheme in modern high data rate wireless communication systems. A well known problem of OFDM system is sensitivity to frequency offset between the transmitted and received signals, which may be caused by Doppler shift in the channel or by the difference between the transmitter and receiver local oscillator frequencies. This carrier frequency offset causes loss of orthogonality between subcarriers and the signal transmitted on each carrier are not independent of each other, leading to inter carrier interference (ICI). In this paper the effect of ICI have analysed and different techniques has been used to reduce the ICI effect. The first method is a self ancellation scheme and other one is using an extended kalman filter. we also analyse the ICI without reduction.