With the envisioned massive connectivity era, one of the challenges for 5G/Beyond 5G (B5G) wireless systems will be handling the unprecedented spectrum crunch. A potential solution has emerged in the form of spectrum sharing, which deviates from a monopolistic spectrum usage system. This paper investigates the medium access control (MAC) as a means of increasing the viability of the spectrum sharing technique. We first quantify the opportunity of spectrum access in a probabilistic manner, a method referred to as opportunistic (OP) map. Based on the OP framework, we propose a random MAC algorithm in which the access of a node is randomly determined with its own OP value. As a possible application of our OP-map based random MAC, we propose a flexible half-duplex (HD)/full-duplex (FD) communication where each pair decides the duplexing mode according to the OP values of the two pair nodes. This approach fits well with the spectrum sharing system since it enables a flexible operation for the spectrum access according to the spectrum usage level. From the numerical analysis, we validate the feasibility and verify the performance enhancements by implementing a field-programmable gate array (FPGA) based real-time prototype. We further carry out extensive 3D ray-tracing based system-level simulations on investigating the network-level performance of the proposed system. Measurements and numerical results confirm that the proposed architecture can achieve higher system throughput than conventional LTE-TDD (time division duplex) systems.

中文翻译：

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超可靠和低延迟无人机通信的数据包错误概率和有效吞吐量


随着设想的大规模连接时代的到来，5G/超越 5G (B5G) 无线系统面临的挑战之一将是处理前所未有的频谱紧缩。一种潜在的解决方案以频谱共享的形式出现，它偏离了垄断的频谱使用系统。本文研究了介质访问控制（MAC）作为提高频谱共享技术可行性的一种手段。我们首先以概率方式量化频谱访问的机会，这种方法称为机会主义（OP）图。基于OP框架，我们提出了一种随机MAC算法，其中节点的接入是用它自己的OP值随机确定的。作为我们基于 OP-map 的随机 MAC 的可能应用，我们提出了一种灵活的半双工 (HD)/全双工 (FD) 通信，其中每对根据两对节点的 OP 值决定双工模式。这种方法非常适合频谱共享系统，因为它可以根据频谱使用水平灵活地操作频谱接入。通过数值分析，我们通过实现基于现场可编程门阵列（FPGA）的实时原型来验证可行性并验证性能增强。我们进一步进行了广泛的基于 3D 射线追踪的系统级仿真，以研究所提出系统的网络级性能。测量和数值结果证实，所提出的架构可以实现比传统 LTE-TDD（时分双工）系统更高的系统吞吐量。