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有限反馈多用户MIMO-OFDMA下行链路预编码

刘毅;张海林
  

  1. (西安电子科技大学 综合业务网理论及关键技术国家重点实验室,陕西 西安 710071)
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2007-02-20 发布日期:2007-02-25

Precoding for the multiuser MIMO-OFDMA downlink with limited feedback

LIU Yi;ZHANG Hai-lin
  

  1. (State Key Lab. of Integrated Service Networks, Xidian Univ., Xi′an 710071, China)
  • Received:1900-01-01 Revised:1900-01-01 Online:2007-02-20 Published:2007-02-25

摘要: 提出了包括波束成形、功率分配和自适应调制的多用户MIMO-OFDMA系统下行链路预编码方案.利用格拉斯曼空间装箱原理预先构建波束成形矢量的码本,在接收端确定最优波束成形矢量并利用有限个比特反馈其索引到发射端.在发射端利用“贪婪算法”进行功率分配和自适应调制.与现有预编码方案相比能够大大减少反馈数据量.

关键词: MIMO-OFDMA, 多用户, 有限反馈, 预编码

Abstract: A precoding scheme for the MIMO-OFDMA downlink is discussed, which includes subcarrier assigning, power allocation and adaptive modulation. By using the beamforming codebook constructed according to the Grassmannian space packing, the optimal beamforming vector is determined at the receiver and its index is conveyed to the transmitter. Then power and bits are allocated to each subcarrier using ‘greedy algorithm’. The feedback data are greatly decreased compared with the existing schemes while maintaining a large capacity.

Key words: MIMO-OFDMA, multiuser, limited feedback, precoding

中图分类号: 

  • TN929.5