Pilot-symbol-aided Channel Estimation in Time and Frequency

The potentials of pilot-symbol-aided channel estimation in two dimensions are explored for mobile radio and broadcasting applications. In order to procure this goal, the discrete shift-variant 2-D Wiener lter is analyzed given an arbitrary sampling grid, an arbitrary (but possibly optimized) selection of observations , and the possibility of model mismatch. Filtering in two dimensions is revealed to outperform ltering in just one dimension with respect to overhead, mean-square error performance and latency. Conceptually, the discrete shift-variant 2-D Wiener lter is the optimal linear estimator for the given problem, however, two cascaded orthogonal 1-D lters are simpler to implement and virtually as good as true 2-D lters. Analytical results are presented, veriied by Monte-Carlo simulations.