Frequency Shifter-RIS Assisted Standalone mmWave Cellular Networks

Frequency shifting-reconfigurable intelligent surfaces (FS-RISs) can be built by a new generation of meta-materials and circuits, which can perform an operation that changes the original frequency spectrum of the transmitted signal. Its exploitation for wireless communications is still in its infancy. In this work, a millimetre wave (mmWave) cellular network aided by FS-RIS is proposed to satisfy the new challenging communication services. The FS-RIS is able to down-convert the carrier frequency of the mmWave signal and spread the control information to the cell by using a more reliable and stable link, relying on better propagation within the lower bands, and a novel multi-frequency beam-management procedure is given. The proposed method can rapidly discover all users in the entire cell by using different sizes of beams. It avoids range penalization due to the better propagation in sub-6 GHz bands, unlike the hierarchical BMP. Additionally, the proposed technique only requires one base station (BS), and hence the delay overhead caused by the information exchange among several BSs is fully avoided, unlike the case of coordinated multi-point (CoMP). Overall, this paper provides a new way to exploit FS-RIS in wireless systems, which can potentially change the way we look at spectrum and interference management for the efficient exploitation of communication applications.