能效优先的用户关联与功率控制协同优化机制

在异构蜂窝网络中，针对系统的能效，提出了一种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方案，该方案表示为非线性混合整数问题。为了求得该问题的最优解，设计了一种迭代算法，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Dinkelbach方法求得最佳的能效因子，然后在内层循环分别求得最佳的用户关联矩阵和传输功率。最终实验结果表明，用户关联与功率控制协同的优化方案在能效和负载平衡方面比固定功率条件下的用户关联策略的性能更优。

Collaborative optimization mechanism of energy efficient user association and power control

This paper presented a collaborative optimization scheme based on the utility function maximization model for user association and power control to increase energy efficiency in heterogeneous cellular networks, this scheme expressed as a nonlinear and mixed integer problem. In order to found the optimal solution of this problem, designed an iterative algorithm, first, the original problem was transformed into a polynomial problem with parameters, then, found the best energy efficiency factor by Dinkelbach method in outer layer, next, obtained the optimal user association matrix and transmission power respectively in inner layer. At last, experimental results shows that the proposed scheme has better performance in terms of energy efficiency and load balancing than the user association strategy at fixed power.