Impact of Nonlinear Distortion on 5G-NR Direct Radiating Array Satellite Downlink

This paper provides an analytical framework to evaluate nonlinear distortion and its impact on the downlink performance of a multi-beam satellite system with an embedded direct radiating array (DRA) featuring the 5G New Radio (5G-NR) standard. Distributed amplification with identical solid-state power amplifiers (SSPAs) across the DRA feeder chains is consid-ered, and the nonlinear distortion power is statistically derived in closed form under the assumption of correlated distortion among antenna feeds. The analysis highlights the key system and array parameters that contribute to the received power. Under a full-frequency reuse scenario, the end-user performance is evaluated in terms of the signal-to-noise-and-distortion ratio (SNDR), and the resulting bit-error rate (BER) demonstrates excellent agreement with numerical simulations. The derived expressions further provide insight into the conditions under which linear and nonlinear impairments in DRA-based systems can be accurately modeled as extra additive Gaussian noise.