On the Ergodic Capacity of Underlay Cognitive Dual-Hop AF Relayed Systems under Non-Identical Generalized-K Fading Channels

TL;DR

This paper analytically investigates the ergodic capacity of underlay cognitive dual-hop AF relayed systems over non-identical generalized-K fading channels, providing new expressions and approximations verified by simulations.

Contribution

It introduces new analytical expressions and accurate approximations for the ergodic capacity under complex fading conditions in cognitive relay systems.

Findings

Derived new closed-form expressions for ergodic capacity.

Validated analytical results with computer simulations.

Provided insights into capacity behavior under generalized-K fading.

Abstract

The ergodic capacity of underlay cognitive (secondary) dual-hop relaying systems is analytically investigated. Specifically, the amplify-and-forward transmission protocol is considered, while the received signals undergo multipath fading and shadowing with non-identical statistics. To efficiently describe this composite type of fading, the well-known generalized-$K$ fading model is used. New analytical expressions and quite accurate closed-form approximations regarding the ergodic capacity of the end-to-end communication are obtained, in terms of finite sum series of the Meijer's-$G$ function. The analytical results are verified with the aid of computer simulations, while useful insights are revealed.