Max-Min Fair Beamforming for Cooperative Multigroup Multicasting With Rate-Splitting

Active RIS Assisted Rate-Splitting Multiple Access Network: Spectral and Energy Efficiency Tradeoff

“…To solve (13), we optimize the prime variables {W, Φ} and the slack variable κ in an iterative manner. According to [54], given {W, Φ}, the optimal κ can be directly obtained as…”

“…Firstly, for the convergence of the quadratic transformation, [54,Theorem 3] has proved that if problem ( 13) is nondecreasing and concave, then the original problem ( 12) is guaranteed to converge. Thus, we mainly focus on the convergence of (13). Specifically, we denote the corresponding objective value of η SE (W, Φ) in ( 13) and the objective of (18) as µ (W, Φ) and µ (t) (W, Φ), respectively, where t denotes the number of iterations.…”

“…where the second inequality holds true since both W (t+1) , Φ (t+1) and W (t) , Φ (t) are the optimal solutions and feasible points of (13). (41) suggests that W (t+1) , Φ (t+1) is better to (13) than W (t) , Φ (t) .…”

“…To be specific, RSMA utilizes linearly precoded rate-splitting (RS) at the transmitter and successive interference cancellation (SIC) at the receiver, which decodes part of the interference and treats the others as noise [7]. Existing works have revealed that RSMA outperforms the orthogonal multiple access (OMA), linear SDMA, and powerdomain NOMA, in the aspects of the spectral efficiency (SE) [8]- [11], max-min fairness [12], [13], and energy efficiency (EE) [14], [15].…”