In this paper, we design a NOMA-based spectrum leasing scheme by considering the following three assumptions for the successive interference cancellation (SIC): (i) the primary network performs the SIC (PSIC), (ii) the secondary network performs the SIC (SSIC), (iii) either the primary or secondary network adaptively performs the SIC depending on the channel conditions (ASIC). We first analyze the achievable rate regions of these schemes. Then, we optimize the power allocation to different layers of the superimposed signal by maximizing the achievable rate of the secondary network under a QoS constraint for the primary network. Finally, we analyze these schemes in terms of the outage probability. The analysis shows that: (i) In terms of the primary network, the PSIC and ASIC schemes perform the same and these schemes outperform the SSIC scheme. (ii) In terms of the secondary network, the ASIC scheme outperforms the other two schemes. (iii) In terms of the primary network, the NOMA-based and OMA-based schemes perform the same, provided that the SIC is performed either adaptively or in a fixed manner at the primary network. (iv) In terms of the secondary network, the NOMA-based scheme outperforms the OMA-based scheme, provided that the SIC is performed adaptively.

中文翻译：

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认知无线电网络中基于 NOMA 的频谱租赁：功率优化和性能分析


在本文中，我们通过考虑连续干扰消除（SIC）的以下三个假设来设计基于NOMA的频谱租赁方案：（i）主网络执行SIC（PSIC），（ii）辅助网络执行SIC (SSIC)，(iii) 主网络或辅助网络根据信道条件自适应地执行 SIC (ASIC)。我们首先分析这些方案的可实现速率区域。然后，我们通过在主网络的 QoS 约束下最大化辅助网络的可实现速率来优化对叠加信号的不同层的功率分配。最后，我们从中断概率的角度分析这些方案。分析表明： (i) 在主网络方面，PSIC 和 ASIC 方案表现相同，并且这些方案优于 SSIC 方案。 (ii)在二级网络方面，ASIC方案优于其他两种方案。 (iii)就主网络而言，基于NOMA和基于OMA的方案执行相同的操作，只要SIC在主网络处自适应地或以固定方式执行。 (iv)在次网络方面，如果自适应执行SIC，基于NOMA的方案优于基于OMA的方案。