Transmit Diversity Method with User's Power Constraint for Distributed Antenna System
Transmit Diversity Method with User's Power Constraint for Distributed Antenna System
复制标题
分布式天线系统中用户功率约束的发射分集方法
DOI：
10.1109/iswpc.2007.342609
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Weilin Wu
中科院分区：
文献类型：
--
作者：
Shenfa Liu;Zhiqiang He;Weilin Wu
在本文中，我们考虑分布式天线系统中的单用户发射分集问题。众所周知，最大比率传输可以在总功率约束（SPC）下最大化接收的SNR（T.Lo，1999）。论文中考虑了具有每天线功率约束（PAPC）的多用户下行链路波束成形问题（（F. Boccardi 和 H. Huang，2006），（Wei Yu 和 Tian Lan，2006））。本文对分布式天线系统中的每个天线施加一个通用的功率约束，称为用户功率约束(UPC)，限制所需用户的天线实际功率不高于该约束。研究了DAS中总功率约束(SPC)和用户功率约束(UPC)下的最佳发射权重设计问题。 SPC和UPC下的权重设计问题被表述为非线性优化问题，我们发现最优权重向量与MRT具有相同的相位。之后，将原问题转化为凸优化问题，利用数值方法求得最优解。此外，提出了一种名为梯度MRT的算法来寻找最优解
In this paper, we consider single user transmit diversity problem in distributed antenna system. As known, maximum ratio transmission can maximize the received SNR under sum power constraint (SPC) (T. Lo, 1999). Multi user downlink beamforming problem with per-antenna power constraint (PAPC) is considered in papers ((F. Boccardi and H. Huang, 2006), (Wei Yu and Tian Lan, 2006)). In this paper, a general power constraint named user's power constraint (UPC) is placed on each antenna in distributed antenna system, which limits antenna practical power for desired user not higher than the constraint. The optimum transmit weight designing problem is investigated under both sum power constraint (SPC) and user's power constraint (UPC) in DAS. The weight designing problem under SPC and UPC is formulated as a nonlinear optimization problem, and we find the optimum weight vector have the same phase as MRT. After that, we transform the primal problem to a convex optimisation problem, and numerical method can be used to get the optimal solution. Furthermore, an algorithm named gradient-MRT is proposed to find the optimal solution