Patent attributes
Adaptive low complexity minimum mean square error (MMSE) channel estimator for OFDM systems operating over mobile channel. Complexity of the estimator is reduced by partitioning sub-carriers into windows where, window size is optimized by considering channel model mismatch error (MME). Three types of adaptive windowed MMSE (W-MMSE) estimators include: A first type, a simplified delay profile applied as channel reference model, and optimum window size adaptive to the estimated signal-to-noise ratio. A second type, a group of candidate channel reference models are considered. The receiver roughly estimates and selects current reference model from candidate group, then adapts optimum window size based on the estimated SNR and selected channel model. A third type, the current channel statistics are finely estimated and window size is iteratively optimized at receiver. The first two adaptive W-MMSE estimators are tolerant to channel model mismatch error and the third captures channel variations to realize real-time estimation.
