理想的混合协同传输系统中,所有的中继节点都参与译码,将带来计算复杂度的提高、节点资源消耗的增加以及信息传输时延的增大。针对多节点的协同无线传输网络,提出了一种基于服务质量(Quality of Service,QoS)的自适应混合协同传输方法,并进行了性能分析,给出了系统误码率(Symbol Error Rate,SER)及中断概率的闭合表达式。该方法根据目的节点的QoS需求以及中继节点的信噪比(SNR)门限,动态地调整中继节点的传输模式,能够减小系统能耗,延长节点使用寿命。数值及仿真结果表明,基于中继节点信噪比门限的混合协同传输能够以较低的实现复杂度获得与理想的混合协同传输相近的性能,理论的性能分析结果与实际仿真结果相一致。
In an ideal hybrid cooperative transmission system, all relay nodes are involved in decoding the received signats from the source, which will result in an increase in computational complexity, resource consumption and transmission delay. In this paper, a novel quality of service (QoS)-based adaptive hybrid cooperative transmission method is proposed in a multi-relay assisted wireless transmission network. The symbol error rate (SER) and outage probability performance of the proposed method are analyzed and their analytical expressions are given. This method can adjust the transmission mode of the relay nodes adaptively according to the QoS requirement at the destination and the threshold of signal-to-noise ratio (SNR) at the relay nodes. Therefore, the resource consumption of the system can be reduced and the life-span of the relay nodes can be extended. Numerical and simulation results show that the performance of the SNR threshold based hybrid coop- erative transmission is close to that of the ideal hybrid cooperative transmission while the former has lower implementation complexity. The theoretical performance analysis is consistent with the results of actual Monte Carlo simulation.