Performance analysis of cognitive decode-and-forward dual-hop relay networks over κ-μ shadowed channels

In this paper, a decode-and-forward relay based dual-hop spectrum-sharing network is considered in cognitive radio perspective. The channels at all links are assumed to be κ-μ shadowed distributed with arbitrary fading and shadowing parameters. The κ-μ shadowed fading is a composite channel model of multipath fading and shadowing, unifying many classical fading models. The outage probability and the ergodic capacity of the considered network are derived under peak interference power constraint of the primary (licensed) network. It is shown that when channels at all links are identically distributed, the secondary user's communication is favored by the severe channel conditions for a low peak interference power constraint of the primary network. For high values of peak interference power, the secondary network shows improved performance under less severe channel conditions. Two simple forms of the outage probability and the ergodic capacity are also evaluated when the channels between secondary nodes are Nakagami-m and Rician/Rician-shadowed distributed. In all scenarios, the analytical results are validated by Monte-Carlo simulations.