毫米波微小区网络中基于公平准则的分布式用户关联算法

由于定向线性视距(Line-of-Sight,LOS)传输和对障碍物的敏感,使得毫米波微小区网络中的用户关联问题更为复杂。提出一种毫米波微小区网络中基于公平准则的用户关联算法,首先建模毫米波信道的不稳定性和用户切换成本,然后将基于公平准则的用户关联算法建模并证明为一个凸问题,利用拉格朗日对偶理论对原问题进行求解。分析与仿真结果表明:(1)当小区切换成本较低时,用户终端(User Equipment, UE)仅关联至单个微基站(Small Base Station, SBS)上为宜;(2)当小区切换成本较高时,UE同时关联至多个微基站为宜;(3)与其它算法相比,文中所提方法吞吐量增益显著。

Distributed User Association Algorithm Based on Fairness Criterion in Millimeter Wave Small Cell Network

User association problems in millimeter- wave small cell networks are more complicated due to its characteristic of directional LOS transmission and sensitivity to obstacles. A distributed user association algorithm based on fairness criterion in millimeter-wave microcell network is proposed. Firstly, the instability of millimeter-wave channel and user switching cost are modeled. Then the user association algorithm based on fairness criterion is formulated and proved to be a convex problem. The Lagrangian duality theory is used to solve the original problem. The analysis and simulation results show that: (1) When the handover cost is low or zero, user equipment (UE) should be only associated with one SBS; (2) When the cell handover cost is high, UE should be associated with multiple SBSs simultaneously; (3) Compared with other algorithms, the proposed algorithm has a significant gain in terms of throughput.