Asymptotic Analysis of Dual-Diagonal LMMSE Channel Estimation in OFDM Systems

Asymptotic analysis of the dual-diagonal (DD) linear-minimum-mean-square-error (LMMSE) channel estimation for orthogonal frequency-division multiplexing (OFDM) systems is presented. We prove that the DD-LMMSE estimator is asymptotically optimal among all DD estimators as the number of subcarriers tends to infinity. Based on the asymptotic analysis, we propose an evolution tool to predict the performance of iterative OFDM systems. Numerical results are presented to verify our analysis.