Estimation of a Channel Factors and Signal Distortions in the MIMO System with a Direct Transform Receiver Under the Conditions of Rayleigh Fading and Doppler Frequency Dispersion

The article is devoted to the algorithm for joint estimation of the non-stationary channel and signal distortions in the direct conversion receiver, based on the use of polynomial approximation in the time domain of the channel matrix elements and the linear least squares method (MLS). This approach has simplicity and relatively low computational complexity. The algorithm works under conditions of a priori uncertainty regarding channel statistics in the presence of phase noise, Rayleigh fading, and Doppler spreading.