论文标题
部分可观测时空混沌系统的无模型预测
Energy-Efficient Optimization for HARQ Schemes over Time-Correlated Fading Channels
论文作者
论文摘要
分析了三种常见的混合自动重复请求（HARQ）方案（包括I型HARQ，HARQ，CHASE COMBINING（HARQ-CC）和HARQ具有增量冗余（HARQ-IR））的能源效率（HARQ-ir），并分析和关节功率分配和速率选择，以最大程度地提高本文的能源效率。与先前的文献不同，考虑到时间相关的褪色渠道，并且在优化中也考虑了两个广泛关注的服务质量（QoS）约束，即中断和远程约束，这进一步将这项工作与先前的工作区分开来。使用渐近中断概率的统一表达，最佳传输功率和最佳速率以封闭形式得出，以最大化能源效率，同时满足QoS约束。然后，这些封闭式解决方案可以对各种HARQ方案的最大能量效率进行彻底分析。据透露，凭借较低的停机限制，通过I型HARQ实现的最大能效率为$ \ frac {1} {4 \ ln2} $ bits/j，而HARQ-CC和HARQ-ir可以达到与$ \ frac {κ_\ infty} $ j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j j y。 1.6617 $。此外，褪色通道中的时间相关对能源效率产生负面影响，而大量允许的传输数量有利于提高能源效率。通过广泛的模拟验证了节能优化的有效性，结果还表明，HARQ-CC可以在三个HARQ方案之间实现能效和光谱效率之间的最佳权衡。
Energy efficiency of three common hybrid automatic repeat request (HARQ) schemes including Type I HARQ, HARQ with chase combining (HARQ-CC) and HARQ with incremental redundancy (HARQ-IR), is analyzed and joint power allocation and rate selection to maximize the energy efficiency is investigated in this paper. Unlike prior literature, time-correlated fading channels is considered and two widely concerned quality of service (QoS) constraints, i.e., outage and goodput constraints, are also considered in the optimization, which further differentiates this work from prior ones. Using a unified expression of asymptotic outage probabilities, optimal transmission powers and optimal rate are derived in closed-forms to maximize the energy efficiency while satisfying the QoS constraints. These closed-form solutions then enable a thorough analysis of the maximal energy efficiencies of various HARQ schemes. It is revealed that with low outage constraint, the maximal energy efficiency achieved by Type I HARQ is $\frac{1}{4\ln2}$ bits/J, while HARQ-CC and HARQ-IR can achieve the same maximal energy efficiency as $\frac{κ_\infty}{4\ln2}$ bits/J where $κ_\infty = 1.6617$. Moreover, time correlation in the fading channels has a negative impact on the energy efficiency, while large maximal allowable number of transmissions is favorable for the improvement of energy efficiency. The effectiveness of the energy-efficient optimization is verified by extensive simulations and the results also show that HARQ-CC can achieve the best tradeoff between energy efficiency and spectral efficiency among the three HARQ schemes.
