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.
|Number of pages||14|
|Journal||Transactions on Emerging Telecommunications Technologies|
|Publication status||Published - 2012|
- Multi-antenna systems
- Multi-user system
- User scheduling
- Zero-forcing (ZF) precoding; limited feedback