An Overview of ICI Self Cancellation Techniques in OFDM Systems

Intercarrier interference (ICI) is one of the critical problems faced in orthogonal frequency division multiplexing (OFDM) systems which is caused mainly due to frequency impairment of local oscillators, Doppler spread of time varying channels which results in carrier frequency offset (CFO). ICI destroys the orthogonality of OFDM signals and degrades the system performance. Many ICI reduction techniques like frequency domain equalization, time domain windowing, pulse shaping and ICI self cancellation have been developed. ICI self cancellation is an efficient technique in terms of bit error rate, computational complexity. Interference in adjacent subcarriers is self cancelled by modulating the same data on adjacent subcarriers with predefined weighting coefficients. This paper gives a brief overview of various ICI self cancellation techniques based on this principle.