Diversity and degrees of freedom in wireless communications

We introduce rigorous definitions for two quantities of interest, diversity and degrees of freedom, that are used to quantify the advantages of a multiple antenna multiple-input multiple-output (MIMO) system when compared to a single-input single-output (SISO) system. These definitions are in a general setting which will allow the computation of these quantities for systems other than multiple antenna MIMO systems. We verify the effectiveness of the definitions by computing the quantities of interest for various existing examples.