Performance analysis of UAV-relaying with time-switching protocol and imperfect channel conditions for cooperative NOMA networks

This paper presents a study that evaluates the performance of cooperative non-orthogonal multiple access (C-NOMA) using decode-and-forward unmanned aerial vehicle (UAV) relays in a downlink scenario, where the channel gains follow the $$\kappa -\mu $$ κ - μ generalized fading model. The research investigates the use of C-NOMA in both indoor and outdoor user cases, with particular attention paid to practical issues such as imperfect successive interference cancellation and channel estimation errors. The study also considers the use of energy harvesting in the UAV relay node using the time-switching-based relaying protocol. Closed-form expressions are derived for the outage probability, ergodic capacity, throughput, and energy efficiency for indoor/outdoor NOMA users, with a focus on satisfying quality of service (QoS) requirements for individual users. The research examines the impacts of key parameters, such as fading channel parameters, power allocation, and splitting power factor, on the performance of the system. The results indicate that the precise selection of power allocation coefficients, QoS requirements, and channel fading parameters are critical factors in achieving high system performance. Extensive simulation results are presented to confirm the analytical expressions.