Semi-blind two-way AF relaying over Nakagami-m fading environment

In this paper, we investigate semi-blind opportunistic amplify-and-forward (AF) selection relaying in two-way dual-hop cooperative communication networks on independent Nakagami-m fading channels. This system is compared to channel state information (CSI)-assisted opportunistic AF selection relaying (CSIA-OAF) where the relays use variable gains for the amplification. In semi-blind opportunistic AF scenario (SB-OAF), the relays use partial CSI-fixed gains to amplify the received signals. In this work, we first derive the expression of the signal-to-noise ratio (SNR) in the case of SB-OAF selection relaying. The obtained SNR is used to process the bounds of average sum-rate, outage probability, and average symbol error rate (SER). Numerical results are used to show the performance of the proposed SB-OAF system compared to the CSIA-OAF relaying. The comparison shows that the cost of the significant reduction of the proposed SB-OAF complexity is obtained for a slight loss in performance compared to CSIA-OAF scenario.