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应用科学学报 ›› 2012, Vol. 30 ›› Issue (5): 455-460.doi: 10.3969/j.issn.0255-8297.2012.05.003

• 通信工程 • 上一篇    下一篇

OFDMA系统中多波束机会波束成形的门限反馈

刘姗1， 杨维1;2   

  1. 1. 北京交通大学电子与信息工程学院，北京100044
    2. 东南大学移动通信国家重点实验室，南京210096
  • 收稿日期:2010-11-13 修回日期:2012-01-04 出版日期:2012-09-24 发布日期:2012-09-25
  • 通信作者: 杨维，博士，教授，研究方向：移动通信网络、MIMO通信系统，E-mail：wyang@bjtu.edu.cn
  • 作者简介:杨维，博士，教授，研究方向：移动通信网络、MIMO通信系统，E-mail：wyang@bjtu.edu.cn
  • 基金资助:

    国家科技支撑计划课题基金(No.SQ2012BAJY3504-03)； 轨道交通控制与安全国家重点实验室自主研究课题基金 (No.RCS2009ZT014)；东南大学移动通信国家重点实验室开放基金(No.2010D11)资助

Threshold-Based Feedback Scheme for Multi-beam Opportunistic Beamforming in OFDMA System

LIU Shan1, YANG Wei1;2   

  1. 1. School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044, China
    2. National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China
  • Received:2010-11-13 Revised:2012-01-04 Online:2012-09-24 Published:2012-09-25

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摘要：

多用户MIMO-OFDMA是未来无线通信的重要技术体制. 当MIMO-OFDMA系统利用全部用户获取多用户分集时，系统反馈量很大. 为了解决这一问题，提出一种基于门限反馈实现部分多用户分集的多波束机会波束成形算法. 用户计算每个子载波上各波束的接收信干比(signal to interference-plus-noise ratio, SINR)，把SINR 超过某一门限的信息反馈给基站. 以预设的平均资源利用率为目标，给出确定最佳门限值的方案，定量分析门限反馈算法的反馈量，证明其反馈总量随用户数目的增大而趋于一个较小的恒定值. 仿真结果表明，通过预设目标平均资源利用率可有效确定门限值，能在吞吐量性能损失很小的情况下显著降低系统的反馈开销.

关键词: 反馈, 门限, 多输入多输出, 正交频分多址, 机会波束成形

Abstract:

 Multi-user MIMO-OFDMA is an important technology in the future wireless communications. In MIMO-OFDMA system, a large amount of feedback information has to be used to achieve multiuser diversity when all users are exploited. To deal with the problem, a multi-beam opportunistic beamforming scheme is proposed, in which partial multiuser diversity is achieved by setting a feedback threshold. Each user calculates the received signal to interference-plus-noise ratio (SINR) of each beam at individual subcarriers. The SINR value is transmitted to the base station only when it is larger than the threshold. The threshold is optimized to guarantee a target average resource utilization rate. The amount of feedback in the proposed scheme is quantified, and it is proved that feedback is limited to a fixed level. Simulation results indicate that optimal threshold can be determined effectively from a predefined resource utilization rate. Also, the feedback load can be reduced significantly with little capacity loss.

Key words: multiple-input-multiple-output (MIMO), orthogonal frequency division multiple access (OFDMA), opportunistic beamforming, feedback, threshold

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