User scheduling for multi-antenna downland channels with limited feedback

Adeel Razi, Yubin Shao, Jinhong Yuan

Research output: Contribution to journalArticleResearchpeer-review

2 Citations (Scopus)


In this paper, several multi-user scheduling algorithms with limited channel feedback are proposed for multi-antenna downland channels.With little channel quality information (CQI) and channel direction information (CDI) at multi-antenna base station, multi-user scheduling algorithms are carefully designed to maximise the potential system throughput while reducing the feedback load. We first propose a scheduling algorithm that requires a quantised CDI and a threshold CQI. Then we propose a scheduling that needs limited feedback of a threshold CDI and a perfect CQI. Both scheduling algorithms are studied in terms of the achievable throughput and the feedback load. Analytical results show that the proposed scheduling with limited channel feedback has a small performance degradation compared with the scheduling with unlimited channel feedback when the thresholds for user scheduling are judiciously designed. Moreover, under a per user total bit rate constraint of the feedback channel, we propose a scheduling with the quantisation of both CQI and CDI. It is demonstrated that allocating 1 bit to the CQI with an optimal threshold and the remaining bits to the CDI achieves the near optimal sum-rate performance.

Original languageEnglish
Pages (from-to)36-49
Number of pages14
JournalTransactions on Emerging Telecommunications Technologies
Issue number1
Publication statusPublished - 2012
Externally publishedYes


  • Multi-antenna systems
  • Multi-user system
  • User scheduling
  • Zero-forcing (ZF) precoding; limited feedback

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