Reconfigurable Intelligent Reflecting Surfaces Enabled Spectrum Access for Beyond 5G Networks

This paper studies the use of Reconfigurable Intelligent Surfaces (RIS) to enable coexistence between Primary and Secondary Spectrum Users. While RIS tech-nology is widely used to improve user throughput or extend coverage to cell edge devices, this study deviates from the conventional use scenario. We model the propagation channel of the users of a Beyond 5G (BSG) cellular networks taking note of the direct path and reflected paths facilitated by the RIS. Simulation results show that the use of the RIS improves the user capacity while reflecting the signals from the direction of the primary users which enables the B5G system to use the primary user's spectrum without harm-fully interfering with it. Further, it is shown that indoor cellular deployment ensures maximum and/or complete protection of the primary spectrum user whereas outdoor deployment requires extra protection mechanisms such as longer separation distances, power control schemes.