Transceiver Impairments in DF/AF Dual-Hop Cognitive Relay Networks: Outage Performance and Throughput Analysis

Transceiver hardware impairments are the distortion noise sources that can degrade performances of wireless systems. In this paper, we analyze the impacts of hardware impairments on outage performance and throughput of the cognitive relay networks with amplify-and-forward (AF) and decode-and-forward (DF) relaying protocol under the transmit power limit constraint. We derive the exact expressions that quantify the impacts of transceiver hardware impairments on outage performance and throughput of the networks and corroborate the results by simulation. It is shown that the impacts of transceiver impairments are nonlinear and increase proportional to the increment of hardware impairment levels. Interestingly, we found that the cognitive relay networks with AF protocol is more susceptible to transceiver hardware impairments than the DF protocol. Consequently, the DF cognitive relay networks provide better outage performance and throughput than the AF cognitive networks in the same specific parameters.