移动场景下的微基站接入算法研究

发布时间：2018-06-09 06:40

本文选题：无线网络 + 负载均衡　；参考：《南京大学》2017年硕士论文

【摘要】：微基站技术是近年来迅速发展起来的一种网络接入技术。随着3G、4G网络的迅猛发展,以及移动网络宽带化的趋势,越来越多用户选择通过移动设备接入网络。为满足用户日益增长的需求,改善热点小区用户的通信质量,减轻宏蜂窝(Macrocell)的负载压力,多种微基站应运而生。典型的微基站包括Wi-Fi、飞蜂窝(Femtocell)、微蜂窝(MicroCell)等。面对有限基站资源的分配、促发移动数据通信瓶颈等问题,负载均衡成为了无线领域研究的一大热点,基站间的协作、用户的移动性等一系列问题等待着研究者去挑战。本文针对负载均衡问题,设计实现了移动场景下的微基站接入算法。微基站接入算法是一种基于拍卖算法的分布式基站接入算法,用户以其对各个基站的依赖度为竞拍价向基站竞拍,而各个基站选取出价最高的用户赋予接入权,以此方式实现微基站资源的负载均衡。我们对比了移动场景下的微基站接入算法与College、RAT-game等经典算法的性能。实验表明,我们的算法其公平性指数(Jain' s fairness index)达到0.83以上,用户丢失率达到12%以下。此外我们还提出了通过信道状态信息数据判断用户移动状态的方法,实现了通过非传感器方法感知用户移动状态。实验结果表明,我们的方法可以达到96.6%的平均准确率。我们将用户动静状态信息应用到微基站接入算法的接入过程,使得算法执行时间缩短至原算法所需时间的65%以下。本文的主要工作在于:一、我们在微基站接入算法的基础上,依据移动场景下的特点和面临的新用户或切换基站用户引起的链式影响等问题提出了打折算法,使得微基站接入算法可以适应于移动场景,缩短了链式影响的影响链长度,保证了算法在移动场景下的用户服务质量(QoS),使得用户与基站的连接趋于稳定而不会频繁切换。二、我们针对移动场景下的基站定价问题,提出了基站重定价算法。由于微基站接入算法的特征,基站报价会在用户的不断拍卖中逐步提高。这导致移动场景中,非高峰时期的微基站定价失去调节作用。我们针对这样的问题提出价格还原策略,使得微基站价格既能反映实时的微基站资源需求情况,又能在合理的时间回调至较低的水平。这个方法保证了微基站接入算法在移动场景中能够长期稳定地运行。三、我们针对移动场景的需要,提出了利用微基站端的信道状态信息(CSI)数据,通过主成分分析的方法做降噪处理,以此数据配合逻辑回归算法来识别用户动静状态。这种方法颠覆了传统的传感器等方法对用户设备的依赖,减少了控制信息对可用带宽的占用,并能快速及时地反映用户的移动状态。
[Abstract]:Microbase station technology is a kind of network access technology developed rapidly in recent years. With the rapid development of 3G 4G network and the trend of broadband mobile network, more and more users choose to access the network through mobile devices. In order to meet the increasing demand of users, improve the communication quality of hot cell users, and reduce the load pressure of Macrocell, a variety of microbase stations emerge as the times require. Typical microbase stations include Wi-Fi, Femto cell, microcellular, and so on. In the face of the limited base station resource allocation, promote mobile data communication bottleneck and other issues, load balancing has become a hot topic in wireless research. The collaboration between base stations and the mobility of users are a series of problems waiting for researchers to challenge. In order to solve the load balancing problem, this paper designs and implements a microbase station access algorithm in mobile environment. Microbase station access algorithm is a distributed base station access algorithm based on auction algorithm. Users bid to the base station based on their dependence on each base station, and each base station selects the highest bid user to give access rights. In this way, the load balance of microbase station resources is realized. We compare the performance of microbase station access algorithm with College RAT-game algorithm in mobile scenario. Experiments show that the fairness index of our algorithm is above 0.83 and the user loss rate is below 12%. In addition, we propose a method to judge the user's mobile state by the channel state information data, and realize the sensorless sensing of the user's mobile state. The experimental results show that our method can achieve an average accuracy of 96. 6%. We apply the user static and dynamic information to the access process of the microbase station access algorithm, which reduces the execution time of the algorithm to less than 65% of the original algorithm. The main work of this paper is as follows: first, based on the microbase station access algorithm, we propose a discounted algorithm according to the characteristics of mobile scene and the chain influence caused by new users or switching base station users. The microbase station access algorithm can adapt to the mobile scene, shorten the length of the chain influence chain, ensure the QoS of the user in the mobile scene, and make the connection between the user and the base station tend to be stable without switching frequently. Secondly, we propose a base station repricing algorithm for base station pricing in mobile scenarios. Because of the characteristic of the microbase station access algorithm, the base station quotation will be improved step by step in the user's auction. This results in the off-peak micro-base station pricing loss of regulation in mobile scenarios. In order to solve this problem, we propose a price reduction strategy, which can not only reflect the resource demand of the microbase station in real time, but also reduce the price to a lower level at a reasonable time. This method ensures that the microbase station access algorithm can run stably in the mobile scene for a long time. Thirdly, according to the need of mobile scene, we propose to use the channel state information (CSI) data of the microbase station and do the noise reduction by principal component analysis (PCA) method, which can be combined with the logical regression algorithm to identify the user's static and static state. This method overturns the dependence of traditional sensors on user devices, reduces the use of available bandwidth of control information, and can quickly and timely reflect the mobile state of users.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

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