In this paper, we demonstrate that despite the power constraints on all transmit nodes caused by the interference temperature limit (ITL) imposed by the primary user, power domain cooperative non-orthogonal multiple access (NOMA) can ensure much higher throughput in underlay cognitive radio networks than conventional orthogonal multiple access (OMA), provided the network is adaptive. We use intelligent user-selection and switching between cooperative NOMA, (non-cooperative) NOMA and OMA to ensure high throughput at the selected far-user while ensuring a desired performance at the selected near-user. The suggested user and mode selection scheme is simple and easy to implement, and yet ensures performance comparable to that attained by a scheme using more information. When the ITL is broadcast by the primary receiver in every coherence interval based on the primary channel, we show that large gains in throughput accrue. Accurate expressions are derived for throughput of the near and far users with these schemes using peak power and ITL-based power constraints. Performance with imperfect successive interference cancellation is also analyzed. Useful asymptotic expressions are derived. Computer simulation results validate the derived expressions.

中文翻译：

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具有简单用户选择的自适应多用户底层 NOMA 传输的性能


在本文中，我们证明，尽管主用户施加的干扰温度限制（ITL）对所有发射节点造成了功率限制，但功率域协作非正交多址（NOMA）可以确保底层认知无线电中更高的吞吐量网络比传统的正交多址接入 (OMA) 更好，前提是网络是自适应的。我们使用智能用户选择以及协作 NOMA、（非协作）NOMA 和 OMA 之间的切换，以确保所选远端用户的高吞吐量，同时确保所选近端用户的所需性能。建议的用户和模式选择方案简单且易于实现，并且确保了与使用更多信息的方案所获得的性能相当的性能。当主接收机在基于主信道的每个相干间隔中广播 ITL 时，我们表明吞吐量会产生巨大的增益。使用峰值功率和基于 ITL 的功率约束，通过这些方案导出近端和远端用户吞吐量的准确表达式。还分析了不完美的连续干扰消除的性能。推导了有用的渐近表达式。计算机仿真结果验证了推导的表达式。