SISO-OFDM channel estimation in the presence of carrier frequency offset

Abstract

In this paper, we consider the effect of CFO (carrier frequency offset) on the performances of LS (least square) and LMMSE (linear minimum mean square error) channel estimation algorithms for SISO (single input single output) OFDM (orthogonal frequency division multiplexing) systems. Compact analytical expressions on the MSE (mean square error) of the channel estimation under the effect of CFO are derived, while conventional works mainly rely on Cramer-Rao bound or Monte Carlo simulations. Based on the expressions derived, it is observed that the MSE contributed by CFO increases at the rate about the square of CFO and it can not be reduced by using more training symbols. What is more, it is also found that LMMSE is more resistant to CFO compared to LS