Cross-Layer Analysis of Multiuser MIMO Systems Employing AMC with Delayed ARQ Feedback

In this paper, we proposed three scheduling policies, which select users according to the channel state and traffic state to get multiuser diversity and reduce the queue delay, in multiuser multiple input multiple output systems. Based on the scheduling policies, we analyze the multiuser queue model and develop a novel cross-layer design scheme combining the queue model with adaptive modulation and coding and automatic repeat request protocol, where the feedback delay of ACK/NAK from the receiver is considered. Simulations are carried out to verify the proposed multiuser scheduling policies and the cross-layer design scheme. It is shown that the proposed multiuser scheduling policies has good performance in the throughput and average delay; the proposed cross-layer design scheme can reduce average delay and obtain good throughput performance. Hence, the proposed scheme can be used to guarantee quality of service requirements.