High-SNR Performance in Gaussian-Class Fading

Wireless communications are affected by several aspects of the multipath fading channel, including clustering, nonlinearity, correlation, scattered waves, and specular components. These aspects have been incorporated into many existing probabilistic fading models. The more aspects are covered, the more complicated is the resulting model. In many cases, the model or the associated system performance or both cannot be obtained in a closed form. As a result, little insight is gained into how each aspect of fading ultimately impacts key metrics such as symbol error rate and outage probability. In this work, we provide a novel asymptotic analysis at high signal-to-noise ratio that yields simple, general, and unified closed-form expressions for the diversity and coding gains of the symbol error rate and outage probability. We cover generalized fading scenarios and all the referred fading aspects. Our results give a handy, yet thorough, characterization of the system performance as impacted by multiple physical aspects of the multipath fading phenomenon. We provide further insights to reveal that all the addressed fading aspects affect the coding gain, whereas only the clustering and nonlinearity affect the diversity gain.