Harnessing RIS-aided MIMO for next-generation 6G wireless communication

As the 6G wireless communication standard evolves, Reconfigurable Intelligent Surface (RIS)-Aided Multiple-Input Multiple-Output (MIMO) communication has emerged as a key driver of 6G technology advancement. RIS-Aided MIMO aims to address several challenges inherent in traditional MIMO, including high cost, high power consumption, and limited coverage, thereby enabling higher data transmission rates, greater gains, and more sustainable energy efficiency for 6G networks. This paper reviews the practical applications of RIS in MIMO communication and outlines the main RIS-aided MIMO architectures. In addition, it investigates the theoretical bases and practical approaches of RIS-aided MIMO from three perspectives: channel modeling, channel estimation, and channel optimization. Meanwhile, it discusses potential future trends and technological breakthroughs. Through a thorough review and analysis of relevant literature, it identifies the significant potential of RIS-aided MIMO in boosting data rates, thereby enhancing signal gain, expanding network coverage and optimizing power efficiency. And this facilitates 6G networks towards greater efficiency and energy savings. Moreover, RIS is expected to become a core technology in next-generation 6G networks by optimizing channel performance.