This paper considers a cooperative cognitive radio network with two primary users (PUs), and two secondary users (SUs) that enables two-way communications of primary, and secondary systems in conjunction with non-linear energy harvesting based simultaneous wireless information, and power transfer (SWIPT). With the considered network, SUs are able to realize their communications over the licensed spectrum while extending relay assistance to the PUs. The overall bidirectional end-to-end transmission takes place in four phases, which include both energy harvesting (EH), and information transfer. A non-linear energy harvester with a hybrid SWIPT scheme is adopted in which both power-splitting, and time-switching EH techniques are used. The SUs aid in relay cooperation by performing an amplify-and-forward operation, whereas selection combining technique is adopted at the PUs to extract the intended signal from multiple received signals broadcasted by the SUs. Accurate outage probability expressions for the primary, and secondary links are derived under the Nakagami-m fading environment. Further, the system behavior is analyzed with respect to achievable system throughput, and energy efficiency. Since the performance of the considered system is strongly affected by the spectrum sharing factor, and hybrid SWIPT parameters, particle swarm optimization is implemented to optimize the system parameters so as to maximize the system throughput, and energy efficiency. Simulation results are provided to corroborate the performance analysis, and give useful insights into the system behavior concerning various system/channel parameters.

中文翻译：

---

Hybrid-SWIPT 双向叠加认知无线电网络的性能分析和优化


本文考虑了一种具有两个主要用户（PU）和两个次要用户（SU）的协作认知无线电网络，该网络能够与基于非线性能量收集的同时无线信息和功率相结合，实现主要和次要系统的双向通信转账（SWIPT）。通过所考虑的网络，SU 能够在许可频谱上实现通信，同时将中继协助扩展到 PU。整个双向端到端传输分四个阶段进行，其中包括能量收集（EH）和信息传输。采用混合 SWIPT 方案的非线性能量收集器，其中同时使用功率分配和时间切换 EH 技术。 SU 通过执行放大和转发操作来帮助中继协作，而 PU 处采用选择组合技术以从 SU 广播的多个接收信号中提取预期信号。在 Nakagami-m 衰落环境下导出了主链路和次链路的准确中断概率表达式。此外，还根据可实现的系统吞吐量和能源效率来分析系统行为。由于所考虑系统的性能受到频谱共享因子和混合 SWIPT 参数的强烈影响，因此采用粒子群优化来优化系统参数，从而最大限度地提高系统吞吐量和能源效率。提供仿真结果来证实性能分析，并提供有关各种系统/通道参数的系统行为的有用见解。