Secure Transmission in 6G Cognitive Radio Network

Abstract

Secure resource allocation in future sixth‐generation (6G) networks is a significant challenge due to the increasing demand for efficient spectrum utilization and advanced multimedia services. Emerging 6G technologies, including cognitive radios (CRs) for dynamic spectrum access, hybrid multiple access (H‐MA) that integrates orthogonal multiple access (OMA) and non‐orthogonal multiple access (NO‐MA), and clustering techniques for efficient user grouping, offer promising solutions to address these challenges. The collective integration of these technologies within cognitive radio networks (CRNs) is referred to as a 6G CRN framework. In this paper, a novel cluster‐assisted CR‐enabled downlink hybrid multiple access (CCRDHMA) scheme is proposed in the presence of eavesdroppers to maximize the sum secrecy rate (SSR). The formulated optimization problem incorporates minimum quality of service (QoS) requirements while satisfying false detection (FD) and missed detection (MD) constraints. To efficiently solve the resulting mixed‐integer nonlinear programming (MINLP) optimization problem, a low‐complexity ϵ$$ \epsilon $$ ‐optimal outer approximation algorithm (OAA) is employed. The performance of the proposed CCRDHMA scheme is evaluated against conventional OMA‐assisted CRN, NO‐MA‐assisted CRN, and other existing secure resource allocation approaches. Extensive simulation results demonstrate that the proposed CCRDHMA framework significantly improves SSR while achieving superior performance in Key Performance Measures (KPMs), including secondary mobile handsets (SMHs) admission within clusters, association with secondary tower (ST), QoS satisfaction, fair power allocation (PA), FD, and MD. Furthermore, the ϵ$$ \epsilon $$ ‐optimal OAA achieves near‐optimal solutions with ϵ=10−3$$ \epsilon =1{0}^{-3} $$ , highlighting its computational efficiency and practical applicability for secure resource allocation in future 6G CRNs.