Explain ICI in ofdm systems

Answer 1

Multi Carrier systems like OFDM has the problem of Inter Carrier Interference(ICI), which results from the loss of Orthogonality between the sub carriers.This happens when the FFT is considered over duration where the subcarrier is non integer number of cycles, which would be the case when multipath is present and the guard time has amplitude is zero.This is reduced by use of cyclic prefix, where we transmit a copy the last part of the symbol followed by the symbol itself.This ensures Orthogonality over the FFT period in case of delayed multipath.

yup...that's all from me.

Regards

Girish .V.V

There are many methods to reduce ICI not only CP like Frequency domain equalization,Time domain windowing,Pulse shaping,Maximum likelihood estimation,Extended kalman filtering and ICI self cancellation.And any one have their own advantages.

Naser