NOMA系统异构网络中联合用户关联和功率控制协同优化

Collaborative Optimization of Joint User Association and Power Control in NOMA Heterogeneous Network

针对非正交多址接入(Non-Orthogonal Multiple Access,NOMA)系统的两层异构网络,提出了基于效用函数最大化模型的用户关联与功率控制协同优化问题。在该问题中将系统总能效作为效用函数,在一定的用户服务质量要求(QoS)和最大功率限制约束下,提出一种联合用户关联和功率控制的算法。该算法首先将原问题转换为带参数的多项式形式的问题,在外层循环利用二分法求得最佳的能效因子,然后在内层循环分别利用分布式用户关联算法和功率控制算法得到最佳的用户关联矩阵和最佳传输功率,最终实现系统总能效最大化。仿真结果表明,所提算法在能效方面比单独的固定功率分配方案和固定用户关联方案性能更优。

Aiming at the two-layer heterogeneous network of non-orthogonal multiple access(NOMA)system,a cooperative optimization problem of user association and power control based on utility function maximization model is proposed.In this problem,the total energy efficiency of the system is taken as a utility function,and a joint user correlation and power control algorithm is proposed under the constraint of certain QoS and maximum power limit.This algorithm first converts the original problem with parameter polynomial form of the problem.In the outer loop,it uses the dichotomy of optimal energy efficiency factor.Then in the inner loop,respectively,it uses distributed user correlation algorithm and power control algorithm to get the best user incidence matrix and optimal transmission power.Finally,it realizes the system energy efficiency maximization.Simulation results show that the proposed algorithm performs better in energy efficiency than the single fixed power allocation scheme and fixed user association scheme.