Fig. 6From: Secure massive MIMO system with two-way relay cooperative transmission in 6G networksSecrecy sum-rate in different \(K\) with \(p_{BS} = 35\,{\text{dBm}}\), \(p_{u} = 30\,{\text{dBm}}\), and \(p_{\max } = 30\,{\text{dBm}}\). Blue line: QCRO; yellow line: PSO; green line: CRO; pink line: RMRS; black line: SRSBack to article page