Performance Analysis of Analytic Interpolator for Comb-Type Pilot-Aided Channel Estimation in OFDM Systems Without ICI

Pilot-aided channel estimation in orthogonal frequency division multiplexing (OFDM) systems often needs an interpolation technique to construct the channel frequency response on nonpilot subcarriers. Many studies on interpolations have been published; however, the performance of interpolations such as cubic spline interpolation and linear interpolation is limited by either the number or the position of the pilot subcarriers. This paper proposes an analytic interpolator developed using a linear least square criterion to replace conventional interpolation techniques for comb-type pilot-added channel estimation in OFDM systems without inter-carrier interference. The performance evaluation of the analytic interpolator is performed both on the basis of theory and through simulation, and the results from both the analyses are found to be in good agreement. The simulation results show that the proposed method can effectively mitigate the ill-influences of limitations on the number and position of the pilot subcarriers and that it also outperforms the cubic spline interpolation and linear interpolation, especially for short or nonequidistant pilot patterns.