Wireless security employing opportunistic relays and an adaptive encoder under outdated CSI and dual-correlated Nakagami-m fading

This paper gives a novel perspective on physical layer security (PLS) and end-to-end (e2e) analysis under dual correlated Nakagami-m fading, and outdated channel state information, by employing (i) decode-and-forward opportunistic relays, and (ii) an adaptive encoder with on/off transmission. Assuming an infinite relay buffer size, two new sets of independent results for (i) non-integer fading parameter m, mathematically employing infinite summations, and (ii) integer m, mathematically employing finite summations, are obtained. The adaptive encoder deployment improves transmission quality, and simultaneously enhances secrecy performance. The proposed e2e analysis coherently links secrecy, and e2e system performance for the first time under dual correlated Nakagami-m fading. Findings for wireless secrecy, and e2e system analysis with the non-integer fading parameter m offer an extra dimension to existing PLS literature, which has chronically been valid for only integer m. Convergence for infinite summations is achieved for a finite number of terms, realising the practicality of the proposed findings. Monte Carlo simulation successfully validates the new findings for non-integer m, and an asymptotic analysis under several specific scenarios is also presented