On the Probability of Adaptation Error in MIMO Systems

In this paper, we are interested in evaluating the probability of adaptation error (PAE) in MIMO systems using adaptive modulation or transmission rate. We attack the problem from two distinct perspectives. Firstly, for a certain rate-feedback system, the PAE is computed by building a Markov model for the channel capacity. The transition probabilities between rate states during the feedback period are approximated using a novel analytical result for the level crossing rate (LCR) of MIMO capacity. Secondly, the impact of channel estimation error on adaptive modulation over eigenmodes is considered. By utilizing the joint dynamic statistics of the eigenvalues, the instantaneous probabilities of choosing inappropriate modulation schemes can be calculated