中文摘要：

该文针对瑞利衰落信道中采用Chase合并混合自动重传请求（CC-HARQ）协议的多跳中继网络提出一种基于跨层设计的能量效率优化策略。为实现能量效率的最大化，基于对数域线性阈值的平均误帧率模型，推导出多跳CC-HARQ系统能量效率的闭合表达式，进而设计了最优发送帧长策略和最优发送功率分配方案，其次，针对发送帧长和发送功率分析了两者的联合优化方案。仿真结果验证了理论分析的正确性和可行性，仿真对比实验表明所提跨层优化设计方案可以有效提升实际多跳网络的能量效率性能。

英文摘要：

The cross-layer optimum scheme of Energy Efficiency （EE） for a multihop relay network with Chase- Combining based Hybrid Automatic Repeat reQuest （CC-HARQ） in Rayleigh fading channels is proposed. In order to maximize EE, a closed-form expression of Energy Efficiency in a multihop CC-HARQ system is derived, which is obtained via an average frame error rate model adopting a new log-domain linear threshold method, and then optimal frame length scheme and optimal transmission power allocation method are further designed, towards the frame length and transmission power, a joint optimization metric of those two parameters is considered. Simulation results verify the correctness and feasibility of the analytical solutions, meanwhile, simulation experiments of comparisons show that the proposed cross-layer optimization design is able to improve the EE performance of practical multihop networks.