Effective Rate Analysis and Optimization of THz-NOMA System Using Fox's H-Function with ME and THI

Abstract

Unlike conventional wireless systems tolerating higher transmission delays, emerging delay-sensitive and mission-critical applications demand ultra-low latency and high reliability. In such scenarios, impairment like misalignment errors (ME) and transceiver hardware impairments (THI) critically affect system performance and compromise quality of service (QoS). Thus, this work analyzes the effective rate of a THz-based NOMA system considering ME and THI effects. Closed-form probability density function (PDF) and cumulative density function (CDF) are derived using Fox's Hfunction to characterize the channel behavior under various THz fading conditions accurately. Interestingly, although the PDF of the instantaneous signal-to-noise ratio appears relatively simple in form, its application in analyzing wireless system performance metrics becomes mathematically intricate. Hence, for the effective rate analysis, we adopt the same methodological framework as presented in [1]. Both fixed and adaptive antennaarray configuration are evaluated, demonstrating that adaptive optimization significantly enhances the effective rate. Finally, the presented analytical results are thoroughly validated through extensive simulation, where their accuracy is confirmed by close assessment with the corresponding Monte-Carlo simulation results. © 2026 IEEE.