In this article, a cybertwin-assisted nonorthogonal random access (RA) system is presented, where the cybertwins of the physical devices at the access point (AP) collect the devices’ information and decide the transmission parameters on behalf of the devices to achieve the maximum system performance. Specifically, the system performance of a pp -persistent slotted CSMA system with nonorthogonal multiple access (NOMA) is analyzed, in which wireless devices transmit data to the ensure the received signal strength at the AP side is either high power or low power with certain probabilities. We first develop an analytical framework to quantify the successful transmission probability and the sum data rate as a function of the above probabilities. Accordingly, the feasible region of the number of high-power and low-power devices to ensure successful transmission is derived. With the analysis, nonconvex optimization problems are then formulated to maximize successful transmission probability and the sum data rate, respectively. To tackle the nonconvexity, an effective and fast-convergent iterative algorithm is designed to obtain the optimal transmission probabilities for the devices. Extensive simulations are conducted to validate our analytical results and demonstrate the benefits of NOMA in RA networks.

中文翻译：

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Cyber​​twin辅助随机接入NOMA性能研究


本文提出了一种基于 Cyber​​twin 辅助的非正交随机接入 (RA) 系统，其中接入点 (AP) 物理设备的 Cyber​​twin 收集设备信息并代表设备决定传输参数，以实现最大系统性能。具体来说，分析了非正交多址接入（NOMA）的 pp 持续时隙 CSMA 系统的系统性能，其中无线设备传输数据以确保 AP 侧接收的信号强度以一定的概率为高功率或低功率。我们首先开发一个分析框架来量化成功传输概率和总数据速率作为上述概率的函数。据此推导了保证传输成功的高功率和低功率设备数量的可行区域。通过分析，然后制定非凸优化问题，以分别最大化成功传输概率和总数据速率。为了解决非凸性，设计了一种有效且快速收敛的迭代算法来获得设备的最佳传输概率。我们进行了大量的模拟来验证我们的分析结果并展示 NOMA 在 RA 网络中的优势。