Rate Splitting in MIMO RIS-Assisted Systems With Hardware Impairments and Improper Signaling

In this paper, we propose an optimization framework for rate splitting (RS) techniques in multiple-input multiple-output (MIMO) reconfigurable intelligent surface (RIS)-assisted systems, possibly with I/Q imbalance (IQI). This can be applied to any problem which the objective and/or constraints are linear functions of rates transmit covariance matrices. Such problems include minimum-weighted and weighted-sum maximization, total power minimization a target rate, energy efficiency (EE) global EE maximization. The may interference-limited system hardware impairments. For sake illustration, consider multicell MIMO RIS-assisted broadcast channel (BC) base stations (BSs) users suffer from IQI. Since IQI generates improper noise, Gaussian signaling (IGS) as interference-management technique that additionally compensate We show RS when combined IGS substantially improve spectral overloaded networks (i.e., number per cell is larger than transmit/receive antennas).