【作者】 李勇；

【导师】 朱宇霞；

【作者基本信息】 武汉邮电科学研究院 ， 通信与信息系统， 2014， 硕士

【摘要】 自优化网络（SON）技术作为LTE系统中的一项关键技术，它的目的是为了有效的减少系统运营成本和提高系统性能以及改善用户体验。SON技术具体分为自配置、自优化和自愈，本文主要研究的是自优化技术中的移动健壮性优化（MRO）和移动性负载均衡（MLB）。MRO的主要目的是减少因切换导致的无线链路失败和减少不必要或者不合理切换导致的网络资源浪费。MRO主要的异常切换场景为过早切换、过晚切换、切换到错误小区、乒乓切换。所以，MRO算法的目的就是通过自动的调整切换参数和重选参数来减少这些异常切换次数。MLB算法的主要目的是通过控制移动性参数（主要为切换和重选参数），在不影响质量和服务（QoS）的情况下把UE分布在合适的小区，从而达到业务均衡。本文的主要创新点有如下三个：1.提出了一种MRO算法，这种算法分为全局优化和局部优化，全局优化只要是自动调整基站级别的切换参数，局部优化主要是自动调整小区级别的切换参数，通过这两种优化方式的结合从而提高LTE系统的切换性能。2.提出了一种MLB算法，该算法在小区负载计算、服务小区和邻居小区的负载交互以及预先计算邻区小区可以接收的负载量的基础上确定了一种自动邻区选择机制，根据邻区负载的大小进行降序排列。该算法每次优化只选择一个邻区，最终在减小服务小区负载的情况下不会是邻居小区处于高负载中。3.提出了一种协调MRO和MLB的方案，该方案不影响单个优化算法的执行，只是通过限制优化切换参数和优化参数的范围来避免两种算法在自动调整参数产生的冲突，同时，该方案可以限制单个算法的优化时间和强制停止某个优化算法以及进行切换参数回退等功能。更多还原

【Abstract】 Self-optimizing network (SON) technology is a key technology in LTE system, itspurpose is reduce system operating costs and improve system performance and improvethe user experience effectively. SON technology is divided into self-configuring,self-optimizing and self-healing. Mobile robust optimization (MRO) and mobility LoadBalancing (MLB), which are belong to the self-optimization techniques, are the goal of thispaper studying.The main purpose of MRO is to reduce radio link failure caused by handover and thewaste of network resources caused by unnecessary handover or unreasonable handover.The abnormal handover scenes of MRO include too early handover, too late handover,handover to wrong cell and ping-pong handover. So, MRO algorithm aims to reduce zheabnormal handover numbers according to adjust handover parameters and reselectionparameters automatically. The purpose of MLB algorithm distributes UE to the suitablecell to achieve balanced business by controling the mobile parameters (handoverparameters and reselection parameters) without affecting the quality and service(QoS). Theinnovations of this paper are the following:1. The paper presents a MRO algorithm, which is divided into global optimization andlocal optimization. Global optimization automatically adjusts the base-level parameters,and local optimization is mainly adjust the cell-level parameters. It improves the handoverperformance of LTE system through these two optimization methods.2. The paper presents a MLB algorithm, which determines an automatic neighborhoodselection mechanism based on cell load calculation, the ineractions between serving celland neighbor cell and evaluate the load of neighbor cell could receiving in advance. Themechanism arranges the order of cell according to the size of cell load. The algorithm onlyselect one neighbor cell for each optimization, and finally reduce the load of serving cellwithout increasing the load of neighbor to high load.3. The paper proposed a coordinated program between MRO and MLB, which does not affect the execution of an individual optimization algorithm. The program can avoidconflict of adjusting parameters in two algorithms by limiting the range of parameters andthe number of parameters. At the same time, the program can limit an individual algorithmoptimization time and stop the algorithm and fallback the parameters.更多还原