Digital Twin Channel for 6G: Concepts, Architectures and Potential Applications

Digital twin channel (DTC) is the real-time mapping of radio channels and associated communication operations from the physical world to the digital world, which is expected to provide significant performance enhancements for the sixth-generation (6G) communication system. This article aims to bridge the gap between conventional channel twin research and emerging DTC by defining five evolution levels of channel twins from aspects including methodology, data category, and application. Up to now, the industry and academia have made significant progress in the fourth-level twin, and have begun the research on the fifth-level twin, that is, autonomous DTC, which offers the opportunity for a new 6G communication paradigm. This article subsequently provides detailed insights into the requirements and possible architecture of a complete DTC for 6G. Then, the feasibility of real-time DTC is experimentally validated. Finally, drawing from the 6G typical usages, we explore the potential applications and the open issues in future DTC research.