LiBeam: Throughput-Optimal Cooperative Beamforming for Indoor Visible Light Networks
LiBeam: Throughput-Optimal Cooperative Beamforming for Indoor Visible Light Networks
复制标题
LiBeam：室内可见光网络的吞吐量最优协作波束形成
DOI：
10.1109/infocom.2019.8737573
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
T. Melodia
中科院分区：
文献类型：
--
作者：
Nan Cen;Neil Dave;Emrecan Demirors;Zhangyu Guan;T. Melodia
室内可见光通信（VLC）是一种很有前途的技术，可以缓解传统射频频段的频谱紧张危机。本文研究了如何通过一组集中控制和部分干扰的发光二极管（led）为室内可见光网络中的用户提供吞吐量最佳的类wifi下行接入。为了减少每个LED视场部分重叠造成的用户之间的干扰影响，我们提出了一种基于形成多个LED集群的合作波束形成方案LiBeam。然后，每个集群通过共同确定用户- led关联策略和led的波束形成向量来服务于用户子集。本文首先提出了协作波束形成问题的数学模型，将其描述为最大化所有VLC用户的总吞吐量。然后，我们设计了一个基于分支定界框架和凸松弛技术相结合的全局最优解算法，解决了由此产生的混合整数非线性非凸规划问题。然后，我们首次设计了一个基于USRP X310软件定义无线电的大型可编程可见光网络测试平台，并通过大量实验验证了所提出的联合波束形成和关联算法的有效性。性能评估结果表明，与次优网络控制策略相比，可以实现95%以上的效用增益。
Indoor Visible Light Communications (VLC) are a promising technology to alleviate the looming spectrum crunch crisis in traditional RF spectrum bands. This article studies how to provide throughput-optimal WiFi-like downlink access to users in indoor visible light networks through a set of centrally-controlled and partially interfering light emitting diodes (LEDs). To reduce the effect of interference among users created by the partial overlap of each LED’s field of view, we propose LiBeam, a cooperative beamforming scheme, based on forming multiple LED clusters. Each cluster then serves a subset of users by jointly determining the user-LED association strategies and the beamforming vectors of the LEDs. The paper first proposes a mathematical model of the cooperative beamforming problem, presented as maximizing the sum throughput of all VLC users. Then, we solve the resulting mixed integer nonlinear nonconvex programming (MINCoP) problem by designing a globally optimal solution algorithm based on a combination of branch and bound framework as well as convex relaxation techniques. We then design for the first time a large programmable visible light networking testbed based on USRP X310 software-defined radios, and experimentally demonstrate the effectiveness of the proposed joint beamforming and association algorithm through extensive experiments. Performance evaluation results indicate that over 95% utility gain can be achieved compared to suboptimal network control strategies.