Trained adaptive filter based approach to mitigate ICI in OFDM system

Orthogonal frequency division multiplexing (OFDM) is a form of multicarrier transmission technique used in today´s modern wireless network´s to achieve high speed data transmission with good spectral efficiency. OFDM offers advantages like Immunity to ISI, timing jitter and robust performance in multi path fading. Due to these advantages OFDM attracted a lot of attention in modern wireless networks like Digital audio broadcasting (DAB), Digital video broadcasting (DVB), Wireless local area network (WLAN), WiMAX etc. However the main drawback of OFDM system is that it is highly sensitive to the frequency offset among the subcarriers. The carrier frequency offset occurs due to mismatch in local oscillator frequency at the transmitter or receiver or by the Doppler phenomenon in mobile channels. This carrier frequency offset degrades the performance of OFDM system by introducing intercarrier interference (ICI). In this paper trained adaptive filtering based technique is proposed to mitigate the effect of intercarrier interference in OFDM system, which leads to the improvement in the performance of the system. Performance analysis of the system is carried out in terms of bit error rate (BER), intercarrier interference power (ICI) and carrier to interference ratio (CIR).