Outage properties of space-time block codes in correlated Rayleigh or Ricean fading environments

The performance of space-time block codes is well understood from an average (over the random channel) error point of view. However, inherent to the idea of diversity gain is the issue of reliability, which is better captured through an outage analysis indicating the quality of performance guaranteed with a certain level of reliability. In this paper, we study the outage performance of a simple space-time block code, the Alamouti scheme, in the presence of correlated Rayleigh or Ricean fading. We derive expressions for the cumulative distribution function of the uncoded symbol error rate and verify the accuracy of our analytical expressions through comparison with numerical results. In addition, we introduce a quantitative measure to compare the diversity gain offered by two channels at a given outage rate.