Coordinated beamforming for the multi-cell multi-antenna wireless system
Coordinated beamforming for the multi-cell multi-antenna wireless system
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DOI：
10.1109/ciss.2008.4558565
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发表时间：
2008-03
期刊：
影响因子：
--
通讯作者：
H. Dahrouj;Wei Yu
中科院分区：
文献类型：
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作者：
H. Dahrouj;Wei Yu
在传统的无线蜂窝系统中，信号处理是在每个小区的基础上执行的；小区外干扰被视为背景噪声。本文考虑了在多天线波束形成系统中跨多个小区协调基站的好处，其中多个基站可以联合优化各自的波束形成器以提高整体系统性能。本文重点关注下行链路场景，其中每个远程用户配备单个天线，但多个远程用户可能在每个小区中同时活动。设计标准是在远程用户处受到信号干扰噪声比 (SINR) 约束的情况下，最小化基站上的总加权发射功率。主要贡献是一种实用算法，能够为全球所有基站高效地找到联合最优波束形成器。所提出的算法基于使用拉格朗日对偶理论将上行链路-下行链路对偶性推广到多小区设置。该算法自然也导致了分布式实现。仿真结果表明，协调波束形成系统的性能明显优于采用每小区信号处理的传统系统。
In a conventional wireless cellular system, signal processing is performed on a per-cell basis; out-of-cell interference is treated as background noise. This paper considers the benefit of coordinating base-stations across multiple cells in a multi-antenna beamforming system, where multiple base-stations may jointly optimize their respective beamformers to improve the overall system performance. This paper focuses on a downlink scenario where each remote user is equipped with a single antenna, but where multiple remote users may be active simultaneously in each cell. The design criterion is the minimization of the total weighted transmitted power across the base-stations subject to signal-to-interference-and-noise-ratio (SINR) constraints at the remote users. The main contribution is a practical algorithm that is capable of finding the joint optimal beamformers for all base-stations globally and efficiently. The proposed algorithm is based on a generalization of uplink-downlink duality to the multi-cell setting using the Lagrangian duality theory. The algorithm also naturally leads to a distributed implementation. Simulation results show that a coordinated beamforming system can significantly outperform a conventional system with per-cell signal processing.