Time domain equalization using linear phase interpolation for OFDM in time variant multipath channels with frequency offset

A loss of subchannel orthogonality due to the time variant multipath channels with frequency offset in orthogonal frequency division multiplexing (OFDM) systems leads to interchannel interference (ICI). The ICI increases the error floor in proportion to the Doppler frequency offset. In this paper, we address two causes of the ICI in the design of OFDM receivers. One is frequency offset and the other is Doppler effect. In order to compensate for the effects of the frequency offset, a linear phase interpolation (LPI) method is proposed in the assumption that the amplitude and the phase of the CIR vary in a linear fashion during one frame. In order to mitigate the Doppler effect we propose the time domain equalization technique.