SIC-Free RSMA Receiver Design via Transfer Learning

Rate splitting multiple access (RSMA) is a promising technology that enhances spectral efficiency through flexible interference management. It splits user messages into common and private components, which are superposed and transmitted over shared wireless resources. In conventional RSMA receivers, successive interference cancellation (SIC) is typically employed to remove the common stream, and channel estimation relies on pilot symbols. The former introduces additional computational complexity and is sensitive to channel state information (CSI) estimation errors, whereas the latter requires dedicated pilot symbols and reduces spectral efficiency. The structural similarity between common and private message detection in RSMA motivates the use of transfer learning (TL) at the receiver. On this basis, an SIC-free joint channel estimation and data detection (JCEDD) receiver making use of TL is proposed. In this receiver, knowledge acquired during common-message detection is utilized to facilitate private-message detection and channel estimation. The receiver avoids explicit SIC, which reduces complexity and limits error propagation, and performs channel estimation jointly with data detection to alleviate pilot overhead. The scheme is not restricted to a specific modulation format or number of transmit antennas and is therefore applicable to a broad class of RSMA-based communication scenarios.