Channel estimation for OFDM systems with high mobility fading channels

In fading channels with very high mobility, the time variation of channel over an orthogonal frequency-division multiplexing (OFDM) symbol period results in a loss of sub-channel orthogonality which leads to inter-carrier interference (ICI). Receivers based on conventional estimation techniques that assume time-invariant channel for one OFDM symbol has error floor for high mobility cases. In this paper we present two-dimensional (2D) pilot-symbol assisted channel estimation for wireless OFDM . This linear interpolation algorithm has the advantage of minimizing the system complexity and processing delay while giving a good approximation to real mobile channel. The performance of the 2D frequency domain estimation algorithm is compared to coherent modulation with perfect channel estimation as well as other conventional methods. We also investigate the performance of proposed channel estimation for different detection techniques. Therefore, we demonstrate the importance of detection methods to assess the channel estimation performance.