自适应调制和HARQ跨层设计的中继协作系统能耗

Energy-Efficient Cross-Layer Design of Adaptive Modulation with Hybrid-ARQ in Cooperative Networks

为了提高协作中继系统能量效率,提出了一种节能的跨层设计方法.在Nakagami-m衰落信道中,通过物理层自适应调制和链路层混合自动重传请求(HARQ)协议跨层设计,首先建立HARQ状态转移图,推导协作中继系统平均总能耗和中断概率表达式,然后提出最小化系统平均总能耗的跨层优化模型,并给出该跨层优化模型的穷尽搜索算法,最后对比分析了非协作HARQ和协作HARQ协议下的中继系统能耗特性.仿真结果表明,协作HARQ比非协作HARQ更节能,且通过自适应调节星座尺寸b的大小,最多可节省80%的能量.

To improve energy efficiency in cooperative relay system, an approach to optimize the energy consumption of cooperative hybrid automatic repeat request （HARQ） protocols with adaptive modulation over Nakagami-m fading channel is proposed. Through modeling the state transition diagram, the total en- ergy consumption and outage probability performance are derived. Further, an optimization framework to minimize the total energy consumption is formulated, and an exhaustive search algorithm is presented. It is shown that the performance of cooperative HARQ is better than the non-cooperative HARQ. In addi- tion, the proposed cross-layer scheme can reach to about 80% energy savings over the non-optimized sys- tem.