The analysis and improvement of linearly interpolative channel estimation in OFDM system

In this paper, we discuss the properties of channel estimation with 1-D linear interpolation filter in OFDM systems from the viewpoint of upsampling in discrete-time signal processing. We found that half of the passband of frequency response of 1-D linear interpolation filter is wasted for interpolating the channel frequency response. The new interpolation filter coefficient is the product of an appropriate linear phase factor and a linear interpolation coefficient. The product causes shifting the frequency response of new interpolation filter, and the appropriate shifting of frequency response will make the passband more effectively. We proposed a simple method to improve 1-D linear interpolation.