基于非正交多址接入的网络切片联合用户关联和功率分配算法

为了满足网络切片多样化需求，实现无线虚拟资源的动态分配，该文提出在C-RAN架构中基于非正交多址接入的联合用户关联和功率资源分配算法。首先，该算法考虑在不完美信道条件下，以切片和用户最小速率需求及时延QoS要求、系统中断概率、前传容量为约束，建立在C-RAN场景中最大化长时平均网络切片总吞吐量的联合用户关联和功率分配模型。其次，将概率混合优化问题转换为非概率优化问题，并利用Lyapunov优化理论设计一种基于当前时隙的联合用户调度和功率分配的算法。最后采用贪婪算法求得用户关联问题次优解；基于用户关联的策略，将功率分配的问题利用连续凸逼近方法将其转换为凸优化问题并采用拉格朗日对偶分解方法获得功率分配策略。仿真结果表明，该算法能满足各网络切片和用户需求的同时有效提升系统时间平均切片总吞吐量。

Joint User Association and Power Allocation Algorithm for Network Slicing Based on NOMA

To satisfy the diversity of requirements for different network slices and realize dynamic allocation of wireless virtual resource, an algorithm for network slice joint user association and power allocation is proposed in Non-Orthogonal Multiple Access(NOMA) C-RAN. Firstly, by considering imperfect Channel State Information(CSI), a joint user association and power allocation algorithm is designed to maximize the average total throughput in C-RAN with the constraints of slice and user minimum required rate, outage probability and fronthaul capacity limits. Secondly, a joint user association and power allocation algorithm is designed according to the current slot by transforming the probabilistic mixed optimalization problem into a non-probabilistic optimalization problem and using Lyapunov optimization. Finally, for user association problem, a greedy algorithm is proposed to find a feasible suboptimal solution; The power allocation problem is transformed into a convex optimization problem by using successive convex approximation; Then a dual decomposition approach is exploited to obtain a power allocation strategy. Simulation results demonstrate that the proposed algorithm can effectively improve the average total throughput of system while guaranteeing the network slice and user requirement.