RIS source decode-and-forward relaying network with interference

Abstract

We consider in this paper the scenario of reconfigurable intelligent surface (RIS) source decode-and-forward (DF) relaying network with interference. The system includes single source of multiple reflecting elements, multiple DF relays, and single destination with interference at the relays and destination. Assuming Rayleigh fading channels, we obtain closed-form accurate approximations for the outage probability. Additionally, we investigate the behavior at high signal-to-noise ratio (SNR) values where the diversity order and the coding gain are obtained. Findings illustrate that the number of reflecting elements N at the source has a small impact on the system coding gain and not on the diversity gain. Furthermore, results show that the number of relays K is affecting the diversity order and is more impactful on the behavior than N. Findings demonstrate that when N = 1, the interference value at the relays and destination is determining, which hop dominates the behavior, whereas when N > 1 the behavior is always dominated by the second hop regardless of the interference value.