A novel hybrid scheme using MLE with pulse shaping for ICI cancellation in OFDM systems

Carrier frequency offset (CFO) in orthogonal frequency division multiplexing systems results in heavy degradation to the system performance. Pulse shaping and Maximum likelihood estimation (MLE) are two of the several techniques available in the literature for reducing the undesired effects caused by CFO using inter carrier interference (ICI) cancellation and CFO correction respectively. In this paper, we combine these two techniques to cancel ICI further, thereby achieving a better bit error rate (BER) performance than the BER achieved by either of the two above mentioned schemes. It has been shown that around 1.7 dB BER performance improvement could be achieved using the new hybrid scheme as compared to MLE technique with low pass filtering. Further, the hybrid scheme adopted in this work is less sensitive to CFO compared to pulse shaping scheme.