非完美条件下的非正交多址接入星地融合网络性能分析

随着星地融合网络(ISTNs)的快速发展，大量的传感器和无线设备都有无线服务的接入需求，从而对星地融合网络的频谱效率和服务质量提出了新的挑战。不同于传统的正交多址接入技术，非正交多址接入(NOMA)技术可在相同的频率下传输不同用户的信号，其被认作为提高星地融合网络频谱效率的有效方法，从而被广泛研究。目前，针对NOMA和星地融合网络的研究大多都是在理想条件下进行的，由此该文研究更加实际的情况，即在非完美串行干扰消除(SIC)、信道估计误差和同频干扰下，对星地融合网络的性能进行研究。该文在假设卫星端和地面端均采用多天线的前提下，推导了系统遍历容量的闭式表达式，验证了非完美条件对于系统性能的影响。同时蒙特卡罗仿真验证了理论分析和推导的正确性。

On the Performance of Non-Orthogonal Multiple Access Integrated Satellite-Terrestrial Networks in Imperfect Constraints

With the rapid development of Integrated Satellite-Terrestrial Networks (ISTNs), large scale sensors and wireless devices have the demand to access the wireless services, which is a new challenge to the spectrum efficiency and quality of service of ISTNs. Different from the conventional orthogonal multiple access technology, Non-Orthogonal Multiple Access (NOMA) can provide communication guarantee for multiple users in the same frequency. It is considered to be an effective technical path to improve the spectral efficiency of ISTNs, hence it has been widely studied. At present, most of the research on NOMA and ISTNs are investigated under perfect condition. Motivated by this condition, the performance of ISTNs with the more practical situation, i.e., imperfect Successive Interference Cancellation (SIC), channel estimation error and co-channel interference, is studied in this paper. Considering that both satellite and terrestrial users use multiple antennas, the closed-form expression of ergodic capacity is derived, which verifies the impact of imperfect conditions on the system performance. Meanwhile, Monte Carlo simulation is performed to verify the correctness of theoretical derivation results.