Conventional AF cooperative protocol under nodes-mobility and imperfect-CSI impacts: Outage probability and shannon capacity

In this paper, we analyze the performance of M-relay amplify-and-forward (AF) cooperative network in the presence of imperfect channel-state-information (CSI) and taking into account the impact of the nodes mobility. We employ the protocol of conventional-relaying (CR), in which all relays are active and participate in the relaying process via orthogonal transmissions. The impact of the nodes mobility is reflected onto the network model by characterizing all of its fading links to be time-selective (time-variant). We first derive exact expressions for the destination instantaneous signal-to-noise-ratios (SNRs), along with their probability density functions (pdfs), through the direct and the ith-indirect (end-to-end) paths. Moreover, closed-form tight approximate expressions are derived for the system outage probability and Shannon capacity. Under these considerations, we show that both of the two derived performance merits experience asymptotic limits, which are also derived. All of the derived expressions are generic enough to be valid for mobile and static nodes and for perfect and imperfect estimations, and therefore, we use them to investigate the system performance under different nodes mobility scenarios. Numerical results along with Monte Carlo simulation results are also provided to verify the accuracy of the derived analytical expressions.