Cooperative Communications for Improving the Performance of Bidirectional Full-Duplex System With Multiple Reconfigurable Intelligent Surfaces

Abstract

In this paper, we exploit the benefits of full-duplex (FD) transmission and reconfigurable intelligent surfaces (RISs) by considering a bidirectional full-duplex wireless communication system with the support of RISs. Specifically, cooperative communications are applied at two FD terminals in a RISsassisted bidirectional full-duplex (RIS-FD) system. In this context, we successfully derive the mathematical expressions of the outage probability (OP) and the ergodic capacity (EC) of the RIS-FD system with a direct link between two terminals and multiple reflecting paths created by RISs over the Rayleigh fading channel. Numerical results show that the performance of the considered RIS-FD system depends significantly on the total number of reflecting elements in the RISs. Particularly, when the total number of reflecting elements is small, the OP and EC saturate at a high signal-to-noise ratio (SNR). However, when the total number of reflecting elements is large enough, OP decreases greatly while EC enhances significantly. In addition, the effect of residual self-interference (SI) caused by FD transmission on OP and EC is remarkable, even the residual SI level is very small. On the other hand, the influence of other system parameters such as the number of RISs (N ) and the number of reflecting elements (L) are also investigated to fully consider the performance of the RIS-FD system. An important observation is that when current techniques cannot completely eliminate SI in FD transmission, the use of multiple RISs with larger L can indirectly reduce the impact of SI and significantly improve the performance of the proposed RIS-FD system. Finally, the obtained expressions are validated via Monte-Carlo simulations.INDEX TERMS Reconfigurable intelligent surfaces, full-duplex, outage probability, ergodic capacity.

Energy efficiency maximisation for STAR‐RIS assisted full‐duplex communications

“…Recently, traditional reflecting-only RIS aided FD systems have attracted considerable interest. In [35], the authors derived outage probability and ergodic capacity of a bidirectional FD system with multiple RISs. In [36], the authors studied the sum rate maximisation (SRM) for an RIS aided FD MIMO system.…”

Performance analysis of power beacon-assisted D2D communication networks in the presence of eavesdropper and co-channel interference

“…In this research, the proposed system model with the energy harvesting (EH) and information processing (IT) is illustrated as shown in [19]- [25]. The proposed system model is drawn in Figure 1 and the time switching protocol is presented in Figure 2.…”

Joint Beamforming and Phase Shifts Design for RIS-Aided Multi-User Full-Duplex Systems in Smart Cities

“…Simulation results showed that RIS joined with the FD relay was superior to other cases. Based on the previous inferences, the authors of [ 21 , 22 , 23 , 24 , 25 , 26 ] considered the union of RIS and FD technology and demonstrated the performance gains. To name a few, the authors of [ 21 ] proposed an SI mitigation method in RIS-assisted FD system, thus mitigating the strong SI to feed in the analog-to-digital converters of finite bit resolutions.…”

“…To name a few, the authors of [ 21 ] proposed an SI mitigation method in RIS-assisted FD system, thus mitigating the strong SI to feed in the analog-to-digital converters of finite bit resolutions. The authors of [ 22 ] formulated the mathematical expressions of outage probability and ergodic capacity. They concluded that RIS could indirectly diminish the adverse consequence of the residual SI and ameliorate the performance in the FD system.…”