Abstract

Intelligent Reflecting Surface-IRS or Reconfigurable intelligent surface-RIS is a transmission technology that can enhance the performance of wireless communication systems by reflecting electromagnetic signals in a specific direction. The question is which RIS-aided scheme is the most appropriate for a given wireless communication scenario, considering performance factors such as energy efficiency and transmit power. In the literature, two oriented RIS-aided schemes are usually determined: The Exhaustive RIS-Aided (ERA) scheme and the Opportunistic RIS-Aided (ORA) scheme. Both schemes have been considered for evaluating the performance of wireless communication. This paper presents a methodology and analysis of RIS technology for wireless communication systems. It presents a mathematical model to optimize the reflected signal’s phase shift and evaluates the system’s performance using numerical simulations. Moreover, it proposes two algorithms for implementing the ERA and ORA schemes. It analyzes the ERA and ORA methods transmit power schemes to determine their energy efficiency. The analysis of the experimental investigations shows that the ORA scheme has sophisticated transmit power values and attains maximum energy efficiency by using less energy compared to the ERA scheme. ORA is superior to ERA in terms of energy and efficiency.

Keywords: Reconfigurable intelligent surface (RIS); RIS-aided schemes; Performance evaluation; Wireless communication; Transmit power; Energy efficiency

Abbreviations: AI: Artificial Intelligence; AP: Access Point; BS: Base Station, CS: Compressive Sensing (theory); CSI: Channel State Information; ERA: Exhaustive RIS-Aided (scheme); IoT: Internet of Things; IRS: Intelligent Reflecting Surface; MISO: Multiple-Input and Single-Output; MMSE: Minimum Mean Square Error (estimation); ORA: Opportunistic RIS-Aided (scheme); QoS: Quality of Service; RIS: Reconfigurable Intelligent Surface; RL: Reinforcement Learning; SNR: Signal-to-Noise Ratio, UAV: Unmanned Aerial Vehicle; 5G: 5th Generation; 6G: 6th Generation