Huge demand for bandwidth and capacity is exhibited by various wireless users and applications, for that purpose now the light-fidelity (Li-Fi)-based technologies are developing. In visible light communication, the hybrid networks based on Wi-Fi and Li-Fi has emerged recently. It is based on the concept of integrating small cell Li-Fi networks with large coverage radio frequency (RF) communication systems. For bidirectional data communication, the access links use shared bandwidth since the link of wireless backhaul invokes in the visible light spectrum. Due to the RF spectrum shortage, the bandwidth of Wi-Fi access point (AP) and the coverage of Li-Fi AP are limited in the outdoor environment. To tackle this issue, the authors propose a swarm intelligence-based improved cuckoo search into the frequency reuse of a hybrid Wi-Fi–Li-Fi network in the outdoor environment. The proposed approach employed bidirectional visible light propagation with non-orthogonal multiple access (NOMA) which is an effective approach towards fifth-generation wireless networks. The NOMA can help various users at the same time with the same frequency and multiple power levels. The system throughput and spectral efficiency are improved with dynamic frequency reuse scheme. The simulation results are compared with conventional techniques to show its effectiveness.

中文翻译：

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Li-Fi第五代双向通信中基于杜鹃搜索算法的最佳频率复用方案

各种无线用户和应用对带宽和容量的需求都很高，为此，基于光保真度（Li-Fi）的技术正在发展。在可见光通信中，最近出现了基于Wi-Fi和Li-Fi的混合网络。它基于将小型蜂窝Li-Fi网络与大范围射频（RF）通信系统集成在一起的概念。对于双向数据通信，访问链接使用共享带宽，因为无线回程链接在可见光谱中调用。由于射频频谱不足，在室外环境中Wi-Fi接入点（AP）的带宽和Li-Fi AP的覆盖范围受到限制。为了解决这个问题，作者提出了一种基于群体智能的改进的布谷鸟搜索方法，用于在室外环境中混合使用Wi-Fi-Li-Fi网络的频率复用。所提出的方法采用具有非正交多址（NOMA）的双向可见光传播，这是对第五代无线网络的有效方法。NOMA可以同时以相同的频率和多个功率级别帮助各种用户。动态频率复用方案提高了系统的吞吐量和频谱效率。将仿真结果与常规技术进行比较以显示其有效性。NOMA可以同时以相同的频率和多个功率级别帮助各种用户。动态频率复用方案提高了系统的吞吐量和频谱效率。将仿真结果与常规技术进行比较以显示其有效性。NOMA可以同时以相同的频率和多个功率级别帮助各种用户。动态频率复用方案提高了系统的吞吐量和频谱效率。将仿真结果与常规技术进行比较以显示其有效性。