Data Detection for Doubly-Selective MIMO Channels Using Decision-Directed Channel Tracking and Exponential Basis Models

The authors present a decision-directed tracking approach to doubly-selective MIMO channel estimation, exploiting the Complex Exponential Basis Expansion Model (CE-BEM) for the overall channel variations, and an Auto-Regressive (AR) model to update the BEM coefficients. They track the BEM coefficients via Kalman filtering, aided by symbol decisions from a Decision-Feedback Equalizer (DFE). The time gap between symbol decisions and required channel estimates, arising from the decision-directed tracking, is bridged by CE-BEM-based channel prediction using the estimated BEM coefficients.