Multiuser Diversity with Two-Step CSI Feedback

This study proposes the performance of a scheduling scheme using two-step quantised channel state information (CSI) feedback. Considering fixed and random access networks, the results are obtained under both short- and long-term power constraints and for both single- and multi-layer transmission techniques. Further, the authors evaluate the asymptotic performance of the proposed scheme and show that, while the users scheduling is based on quantised CSI feedback in the first round, the second round of partial CSI feedback can be provided by either channel quantisation or hybrid automatic repeat request feedback, leading to the same forward channel average rate. In comparison with the case of no CSI feedback, the results indicate substantial average rate increment with limited number of feedback bits. Also, the average rate increases via successive partial CSI feedback when compared with one-step CSI feedback schemes