论文标题
两用户Noma的准降解概率比里奇亚式褪色通道
Quasi-Degradation Probability of Two-User NOMA over Rician Fading Channels
论文作者
论文摘要
与正交倍数访问（OMA）相比，非正交多访问（NOMA）具有更高的多用户无线网络频谱效率的巨大潜力。先前的工作已经建立了该条件，指的是准降解（QD）概率，在该概率下，NOMA与两用户案例的容量型脏纸编码相比，没有性能损失。现有结果假设没有视线（LOS）的瑞利褪色通道。在许多实际情况下，通道LOS组件对于链接质量至关重要，在该链接质量下，频道增益遵循里奇亚人的分布而不是瑞利分布。在这项工作中，我们分析了多输入和单输出（MISO）通道的QD概率。 QD概率在很大程度上取决于两个用户通道之间的角度，这涉及随机向量中的矩阵二次形式和随机矩阵。使用确定性的LOS分量，矩阵二次形式的分布是非中心的，它极大地使QD概率的推导变得复杂。为了解决这一难度，提出了一系列近似值，该近似值在误差频道上产生了QD概率的封闭式表达。提出了数值结果，以评估分析的准确性，并深入了解诺玛在里奇亚褪色通道上的最佳性。
Non-orthogonal multiple access (NOMA) has a great potential to offer a higher spectral efficiency of multi-user wireless networks than orthogonal multiples access (OMA). Previous work has established the condition, referred to quasi-degradation (QD) probability, under which NOMA has no performance loss compared to the capacity-achieving dirty paper coding for the two-user case. Existing results assume Rayleigh fading channels without line-of-sight (LOS). In many practical scenarios, the channel LOS component is critical to the link quality where the channel gain follows a Rician distribution instead of a Rayleigh distribution. In this work, we analyze the QD probability over multi-input and single-output (MISO) channels subject to Rician fading. The QD probability heavily depends on the angle between two user channels, which involves a matrix quadratic form in random vectors and a stochastic matrix. With the deterministic LOS component, the distribution of the matrix quadratic form is non-central that dramatically complicates the derivation of the QD probability. To remedy this difficulty, a series of approximations is proposed that yields a closed-form expression for the QD probability over MISO Rician channels. Numerical results are presented to assess the analysis accuracy and get insights into the optimality of NOMA over Rician fading channels.
