硬件损伤下NOMA-MEC网络性能分析和优化

Performance and Optimization of NOMA-MEC Networks with Hardware Impairments

在基于非正交多址(NOMA)边缘计算(MEC)网络的研究中,忽略了收发机可能存在硬件损伤的情况。但是,硬件损伤对NOMA-MEC网络的计算性能具有一定的影响。因此,在由2个边缘用户和一个边缘服务器构成的NOMA-MEC网络中,利用随机过程等知识推导出在任意给定硬件损伤参数条件下的任务成功计算概率。在此基础上,通过优化部分卸载策略和用户发射功率等参数使任务成功计算概率最大化,并求得优化问题最优解的闭合表达式。仿真实验结果表明,当NOMA用户的发射功率无限大时,成功计算概率趋向一个常数且该常数小于1;用户任务的成功计算概率会随着损伤参数的增加而降低。

Research on mobile edge computing(MEC)networks based on non-orthogonal multiple access(NOMA)have ignored hardware impairments in the transceiver.However,hardware impairments may have an impact on the computational performance of the NOMA-MEC network.A NOMA-MEC network consisting of two edge users and an MEC server is considered,and the probability of successful computation,for given hardware impairment parameters,is derived based on stochastic processes.Then,the successful computation probability of the task is maximized by jointly optimizing the partial offloading strategy and the user transmit power,and the optimal solution is derived into the closed form.The simulation results indicate that as the transmitting power of NOMA users tends towards infinity,the success probability of computation converges to a constant value that is less than one.Additionally,the success probability of computation for user tasks decreases with an increase in the impairment parameter.