MIMO Diversity in the Presence of Double Scattering

The potential benefits of multiple-antenna systems may be limited by two types of channel degradations-rank deficiency and spatial fading correlation of the channel. In this paper, the authors assess the effects of these degradations on the diversity performance of Multiple-Input Multiple-Output (MIMO) systems, with an emphasis on Orthogonal Space-Time Block Codes (OSTBC), in terms of the Symbol Error Probability (SEP), the Effective Fading Figure (EFF), and the capacity at low Signal-to-Noise Ratio (SNR). In particular, they consider a general family of MIMO channels known as double-scattering channels-i.e., Rayleigh product MIMO channels - which encompasses a variety of propagation environments from independent and identically distributed (i.i.d.) Rayleigh to degenerate keyhole or pinhole cases by embracing both rank-deficient and spatial correlation effects.