Ergodic Capacity of Two-Way UAV-aided Integrated Space-Air-Ground Network with NOMA

Integrated space-air-ground network (ISAGN) has been regarded as an important infrastructure of the next-generation network, which can offer massive access and seamless connections for users in a wide coverage area. This paper utilizes non-orthogonal multiple access (NOMA) technique to improve the spectrum efficiency of the ISAGN. Besides, two-way relay technique is introduced in ISAGN to boost the spectrum efficiency. Then, we conducted the ergodic capacity of two-way unmanned aerial vehicle (UAV)-aided ISAGN with NOMA. We first briefly establish a two-way UAV-aided ISAGN, by considering the imperfect channel state information (CSI) and successive interference cancellation (SIC). To obtain deeper insights, the closed-form expression of ergidic capacity for the considered system is derived. Finally, numerical simulations are provided to evaluate the performance of the system and reveal the impacts of imperfect factors.