Deterministic Modeling and Long Range Prediction of Fast Fading Channels with Applications to Mobile Radio Systems

Abstract

In wireless communication systems, the direct signal and the reflected signals form an interference pattern resulting in a received signal given by the sum of these components. They are distinguished by their Doppler shifts at the mobile. Since the parameters associated with these components are slowly varying, the fading coefficients can be accurately predicted far ahead. We introduced a novel algorithm for long range prediction of fading channels. This algorithm finds the linear Minimum MeanSquared Error (MMSE) estimate of the future fading coefficients given a fixed number of previous observations. We show that thesuperior performance of this algorithm is due to its longer memoryspan achieved by using lower sampling rate given fixed model orderrelative to the conventional (data rate) methods of fading prediction. This long range prediction capability for fading channels would provide enabling technology for accurate power control, reliable transmitter and/or receiver diversity, more effective adaptive modulation and coding and improvements in many other components ofwireless systems. In this thesis, we demonstrate that largeimprovements in the performance are possible for both flat and frequency-selective rapidly varying fading channels when the proposed prediction method is used. We illustrate the performance enhancements both at the transmitter and the receiver with both theoretical and simulation results.