能量捕获无线通信系统的资源优化

发布时间：2018-08-28 10:44

【摘要】：通信网络的快速发展深刻地改变着人们的生活方式,同时也面临着严峻的能耗问题。能量捕获技术的出现为解决节能减排问题提供了一种新的契机,该技术通过收集环境中的可再生能源并将其用于维持用电设备的能量供给。同时,无线能量传输技术也为无线远程能量供给提供了新的技术途径。但是,无线网络状态的随机性与复杂性极大的影响着网络业务的服务质量。因此,研究如何克服网络的不确定性,高效使用捕获到的能量完成数据业务传输以及提高无线能量传输效率具有深远的现实意义。本文以能量捕获技术为基础,采用控制优化的理论与技术手段,对无线能量传输进行了深入的讨论与分析,同时将能量捕获技术与具体的视频媒体业务数据传输相结合,研究能量捕获网络中视频数据传输的资源配置与调度。具体工作内容如下:1)研究无线环境中无线能量的高效传输。无线网络中,无线信道的随机变化以及能量请求的不确定性极大的影响着无线能量的传输效率,优质的信道状态有利于能量的高效传输,贫乏的信道质量则会消耗较多的传输能量。因此,为了提高能量传输的效率,避免在劣质信道时刻传输能量,本文将通信网络中的无线能量传输过程建模为Markov决策过程,综合考虑能量请求的变化与无线信道的随机性,分别对能量传输不可中断场景和可中断场景进行分析与讨论,然后采用动态规划方法计算出每个时隙最优传输能量的阈值,根据实际传输能量消耗与阈值的对比,确定无线能量传输的适宜时刻。最后,文中设计了一系列仿真实验,实验结果表明所提方法可以较高的提升无线能量传输的效率。2)研究能量捕获环境中具有QoE保障的可伸缩视频传输。能量捕获网络中,信道状态和捕获到的能量具有随机不确定性的特点,因此合理的资源调度策略对保障数据业务的服务质量具有重要意义。本文研究能量捕获无线网络下可伸缩视频自适应传输的优化问题。由于传输高质量视频时需要消耗较多的能量,因此文中基于大偏差原理通过观测电池中能量存储状态及其变化趋势提出能量饥饿概率的估计模型。该模型可以精确估计未来时刻出现能量饥饿的概率,并指导视频数据传输过程中的层数选择。此外,为了降低视频质量的波动性,文中还采用摄动理论来分析与评估视频层数增加时对视频质量的影响。基于此,本文推导出另一种低中断率、轻波动性的改进型视频传输调度策略。为了验证所提算法的性能,文中分别对两种方法进行了仿真实验,实验结果表明,所提出的两种方法都能够适应不同的能量捕获速率,很好的保障视频高质量传输,且改进型方法获得的传输中断率更低。3)研究能量捕获无线网络中多用户的可伸缩视频传输。多用户视频服务网络中,网络的复杂性、多个用户的协调性以及捕获能量的不确定性,为高质量视频服务带来了新的挑战。为了满足视频服务的需求,本文将能量捕获网络中多用户视频服务问题建模为带约束的随机优化问题,即满足播放平滑约束与能量约束下最大化系统效用。基于Lyapunov优化方法,文中通过建立平均数据队列和能量队列,将最初时间平均效用问题分解为三个独立的瞬时优化子问题,然后根据每个子问题的结构特征获得视频服务过程中的四个调度参数,即能量捕获决策、视频层数选择、传输连接分配以及功率配置。最后,通过仿真实验验证所提算法获得系统性能,实验结果表明所提算法可以很好的适应环境的变化,提供高质量的视频业务服务。
[Abstract]:The rapid development of communication networks has profoundly changed people's lifestyle, but also faced severe energy consumption problems. The emergence of energy capture technology provides a new opportunity to solve the problem of energy conservation and emission reduction. However, the randomness and complexity of wireless network state greatly affect the quality of service of network services. Therefore, how to overcome the network uncertainty, efficiently use the captured energy to complete data service transmission and improve wireless energy transmission is studied. The transmission efficiency has far-reaching practical significance. Based on the energy capture technology, this paper discusses and analyzes the wireless energy transmission by means of control optimization theory and technology, and combines the energy capture technology with the specific video media service data transmission to study the video data transmission in the energy capture network. Resource allocation and scheduling. Specific tasks are as follows: 1) Study the efficient transmission of wireless energy in wireless environment. In wireless networks, the random changes of wireless channels and the uncertainty of energy requests greatly affect the efficiency of wireless energy transmission. Therefore, in order to improve the efficiency of energy transmission and avoid transmitting energy in bad channel time, the wireless energy transmission process in communication network is modeled as Markov decision-making process. Considering the change of energy request and the randomness of wireless channel, the uninterruptible and neutral scenarios of energy transmission are respectively considered. After analyzing and discussing the outage scenario, the optimal transmission energy threshold of each slot is calculated by dynamic programming method, and the appropriate time of wireless energy transmission is determined by comparing the actual transmission energy consumption with the threshold. Finally, a series of simulation experiments are designed, and the experimental results show that the proposed method can improve the performance of wireless energy transmission. 2) Research on scalable video transmission with QoE guarantees in energy capture environments. In energy capture networks, channel states and captured energy are characterized by random uncertainties. Therefore, a reasonable resource scheduling strategy is of great significance for guaranteeing the quality of service of data services. In this paper, an energy hunger probability estimation model based on large deviation principle is proposed by observing the state of energy storage in batteries and its changing trend. In addition, in order to reduce the fluctuation of video quality, perturbation theory is used to analyze and evaluate the effect of increasing layers on video quality. In order to verify the performance of the proposed algorithm, the two methods are simulated. The experimental results show that the proposed two methods can adapt to different energy capture rates, ensure high quality video transmission, and the improved method achieves lower transmission interruption rate. Scalable video transmission. In multiuser video service networks, the complexity of the network, the coordination of multiple users, and the uncertainty of capture energy pose new challenges to high quality video services. Based on Lyapunov optimization method, the initial time average utility problem is decomposed into three independent instantaneous optimization sub-problems by establishing an average data queue and an energy queue, and the video service is obtained according to the structural characteristics of each sub-problem. Four scheduling parameters, i.e. energy capture decision, video layer selection, transmission connection allocation and power allocation, are included in the process. Finally, the performance of the proposed algorithm is verified by simulation experiments. The experimental results show that the proposed algorithm can adapt to the changing environment and provide high-quality video service.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN92

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