中文摘要：

提出了一种新的跨层设计方案,即选择中继重传方案（SN-RT,selective-node-based retransmission scheme）.它把物理层中的协作分集技术和数据链路层中的自动请求重传（ARQ）协议有效地结合起来.在重传过程中,依据中继与目的节点间链路的瞬时信噪比选择一个最佳中继,联合源节点进行Alamouti空时编码.在Rayleigh衰落环境和MPSK调制下,给出了确切的吞吐量表达式.结果显示,相比于固定中继重传方案（FN-RT,fixed-node-based retransmission scheme）,SN-RT跨层方案能明显进一步提升系统吞吐量.

英文摘要：

This paper proposes a novel cross-layer design scheme, named selective-node-based retransmission scheme （ SNRT） .It efficiently combines cooperative diversity at the physical layer and automatic repeat request（ARQ） at the data link layer.At the stage of retransmission, the source together with an optimal relay,which is selected based on the instantaneous signal-to-noise ratio of relay-to-destination link,transmit signals to the destination node by following Alamouti-based space-time coding.The explicit expressions of throughput with MPSK modulation over Rayleigh fading channels are derived. The simulation results show that com- pared to the fixed-node-based retransmission scheme（FN-RT） ,SN-RT scheme can notably improve system throughput.