LAUSR

Integrated satellite-high altitude platform-terrestrial networks (IS-HAP-TNs) and non-orthogonal multiple access (NOMA) scheme are considered to be the key components of next generation networks, which can satisfy the demands of high-quality transmission, wide coverage and large-scale connections. In this letter, we analyze the performance of NOMA-based IS-HAP-TNs with transmit antenna selection (TAS) in the presence of imperfect channel state information (CSI) and successive interference cancellation (SIC). Specifically, considering the requirements of different users for spectrum efficiency, two TAS schemes are proposed to balance the system performance and complexity. In addition, the closed-form expressions for the outage probability of the IS-HAP-TNs in the presence of imperfect CSI and SIC are derived to verify the performance of different schemes. Besides, the asymptotic outage behavior and diversity orders at high signal-to-noise ratios are also presented to get further insights. Finally, Monte Carlo simulations manifest the advantages and disadvantages characters of two schemes and reveal the impacts of key parameters on the system performance.