I. Introduction
In the theory of wireless communications, average bit error rate (ABER), average channel capacity (ACC) and outage probability/capacity (OP/OC) are some of those average performance measure s (APMs) that are commonly utilized to investigate various performance aspects of communications systems. Each APM serves a pivotal role not only in interpreting the discovered techniques for higher data transmission, efficient mobility and lower complexity but also in gaining insight into the requirements for achieving sophisticated usage of radio frequencies with a higher quality of service. As such, each APM has been used to quantify the performance gains/impairments under various communication scenarios and to comprehend how factors arising from design/implementation (e.g. channel noise, receiver noise, diversity, interference, multipath shadowing and fading) affect overall system performance [2]–[4].