RIS-Assisted Full Duplex Communication Using ZS-BF and Signal Alignment Technique

Reconfigurable intelligent surface-assisted full duplex (RIS-FD) communication is attracting attention because of its ability to solve the issue of spectrum crunch and improve signal strength in shadowing areas. However, its potential has not been exploited due to various interferences, like self-interference and loop-interference. This letter proposes a RIS-FD communication where the loop interference is mitigated by employing a zero steering beamforming (ZS-BF) technique. The proposed scheme also becomes effective by partitioning the single RIS into two parts to support simultaneous uplink and downlink communications. Additionally, the system has been examined under imperfect channel state information to make it more practical. Further, the closed-form analytical expressions of the outage probability, ergodic capacity, and energy efficiency are derived for the proposed scheme, as well as corroborated with simulation results. The comparative analysis and its results show that the proposed scheme yields superior outcomes compared to the existing work in the literature.