Block Processing for One-Dimensional Adaptive Channel Estimation Algorithms for OFDM Systems

Adaptive pilot-aided channel estimation in frequency domain for Orthogonal Frequency-Division Multiplexing (OFDM) transmission is considered in this paper. More specifically, adaptive block and non-block processing algorithms for the first one-dimensional filtering stage of a two-stage channel estimator are compared. The estimator consists of Two One-Dimensional filtering stages (2 × 1D) as a common and efficient approximation of the optimal one-stage but Two-Dimensional (2D) estimator. The optimal block algorithms for the first stage, namely the Normalized Block Least-Mean-Square (NBLMS) and Block Recursive Least-Squares (BRLS) algorithm, are deduced from the standard non-block Normalized Least-Mean-Square (NLMS) and Recursive Least-Squares (RLS) algorithms, respectively.