Design and Application of Intelligent Reflecting Surface (IRS) for Beyond 5G Wireless Networks: A Review

Abstract

The existing sub-6 GHz band is insufficient to support the bandwidth requirement of emerging data-rate-hungry applications and Internet of Things devices, requiring ultrareliable low latency communication (URLLC), thus making the migration to millimeter-wave (mmWave) bands inevitable. A notable disadvantage of a mmWave band is the significant losses suffered at higher frequencies that may not be overcome by novel optimization algorithms at the transmitter and receiver and thus result in a performance degradation. To address this, Intelligent Reflecting Surface (IRS) is a new technology capable of transforming the wireless channel from a highly probabilistic to a highly deterministic channel and as a result, overcome the significant losses experienced in the mmWave band. This paper aims to survey the design and applications of an IRS, a 2-dimensional (2D) passive metasurface with the ability to control the wireless propagation channel and thus achieve better spectral efficiency (SE) and energy efficiency (EE) to aid the fifth and beyond generation to deliver the required data rate to support current and emerging technologies. It is imperative that the future wireless technology evolves toward an intelligent software paradigm, and the IRS is expected to be a key enabler in achieving this task. This work provides a detailed survey of the IRS technology, limitations in the current research, and the related research opportunities and possible solutions.

Feature-Based Generalized Gaussian Distribution Method for NLoS Detection in Ultra-Wideband (UWB) Indoor Positioning System

“…In brief, among the mentioned NLoS identification methods in the literature, the threshold difference between the first-path power and received power have been widely used in different ML algorithms [21], [39], [40]. In our analysis we will use the above 7 signal components to calculate our 4 key features which are the estimated distance (5), first path power level (17), received power level (18), and the power difference between the first and the received power level (19). The first-path power level is calculated as [21], [41] FP Level = 10 × log 10…”

Review Paper on Hardware of Reconfigurable Intelligent Surfaces

“…It is predicted that beyond-5G/6G communication will have a paradigm shift in communication systems like previous communication systems [36]. In [37][38][39][40] review of the RISs was presented describing its distinct feature, benefits of the RIS, and potential future use case of the RIS. Theoretical studies of RIS like beam-forming optimization were presented by various authors over the years [41][42][43][44][45][46][47].…”

“…Different performance metrics and analytical approaches of the IRS were presented in that paper. In [38], the authors presented a review of RIS, its current limitations, and the future development of RIS. An emerging area of RIS-empowered smart radio was discussed in [40].…”

Capacity Analysis of Intelligent Reflecting Surface assisted RSMA System with Perfect and Imperfect CSI for 6G

“…To solve the constraints of NOMA and space division multiple access (SDMA), a RSMA for downlink system has been developed, which would provide an acceptable solution while retaining the advantages of NOMA and SDMA. By solving the problem of maximizing WSR in MISO-BC, the author presented RSMA with SDMA and NOMA in ref [18]. In ref [19], a novel IRS-RS framework to enhance the performance of multi-user downlink communication system by employing an IRS near to cell-edge users at the BS.…”