A tracking based BEM algorithm for OFDMA channel estimation in high Doppler spread

In this paper, we investigate the Channel Impulse Response (CIR) estimation in an Orthogonal Frequency Division Multiple Access (OFDMA) uplink using a tracking based Basis Expansion Modeling (BEM) algorithm. By introducing a new tracking term in the BEM coefficients that gives the rate of change of the coefficients, the algorithm is particularly suitable for high mobility application. Specifically, the algorithm estimates the BEM coefficients for each OFDMA block in an iterative manner based on using a new objective function that takes into consideration first order variations in the coefficients of the current and adjacent blocks.