分层异构网络中干扰管理、用户连接及自组织技术研究

发布时间：2018-08-16 10:00

【摘要】：近年来,随着智能手机、平板电脑以及其它多媒体移动设备的普及,网络规模不断扩大,移动数据业务呈指数增长。同时人们对数据传输速率的要求也越来越高。传统蜂窝网络在频谱效率以及网络覆盖等方面受到限制,并不能满足未来网络需求。为了解决这一问题,新型的网络架构,即分层异构网络(Heterogeneous Network, HetNet),逐渐成为研究热点。该网络由宏基站小区以及部署在宏基站小区覆盖范围内的小小区构成,与传统扁平网络相比,其拓扑结构更具层次性。作为宏基站小区的补充,小小区中放置不同类型的低功率基站,如微微基站、毫微微基站、中继等。这些小小区能够提升网络容量,实现网络数据分流解决盲区、热点、弱覆盖的问题,使运营商以较低代价为用户提供更优质的无线宽带语音及数据业务。本论文针对HetNet中的干扰管理、用户连接以及自组织技术进行了相关研究,提出了相应的创新性解决方案,并通过理论分析和计算机仿真证明了所提算法的性能。本论文的主要贡献以及成果主要概括为如下三个方面： 1)在混合分层异构网络中提出了一种基于动态资源分配的干扰管理方案。首先利用混合式分层异构网络特点,提出基于动态资源分配的干扰管理问题。为了减轻操作管理中心(Operation and Management Entity,OM)的压力,该问题分为基于子载波分配的干扰粗调以及基于功率控制的干扰细调两部分。第二,针对干扰粗调,考虑不精确信道条件,OM采用离散随机逼近算法为所有用户搜索最优子载波集合,从而最小化网络总干扰。针对干扰细调,低功率基站采用卡莱议价算法调整用户功率,最终优化本地收益,该算法将向量优化转化为线性优化,具有较低算法复杂度。最后,在仿真中将离散随机逼近算法以及卡莱议价算法与现有算法相比较,验证了所提干扰管理方案性能的提升。 2)提出了分布式分层异构网络中联合资源分配的用户连接方案。首先,分析分布式分层异构网络特点,描述低功率基站可用资源；通过最小潜在延迟公平函数推导优化目标,该目标能够保证用户间公平性,兼顾优化网络传输速率。第二,建立联合资源分配的用户连接模型。将节约网络能量消耗以及降低小小区所承受的干扰作为该模型的约束条件。第三,提出基于三阶段搜索算法的用户连接以及资源分配方案。为实现帕累托最优,算法包括三个阶段：首先搜索满足支撑非支配极点的解；其次搜索满足支撑非极点以及非支撑非支配点的解；最后在前两个阶段构成解的空间中,根据系统要求从解集中寻找系统最优解。最后,通过仿真验证对比所提方案以及现有方案的性能。 3)提出了一种自组织分层异构网络中基于多维因素的资源优化配置方案。首先,根据分层异构网络能量效率、传输功率消耗以及稳定性三个因素建立分层异构网络资源自配置模型。资源配置包括用户连接以及功率值设置两部分。第二,设计用户选择与功率分配分步执行算法,分别对用户连接及功率配置相应参数。为进一步增强基站的自组织功能,设计用户选择与功率分配联合执行方案。该方案通过强化学习方法分析周围环境信息,具有较高的智能性。最后,通过仿真验证资源自配置策略对于自组织分层异构网络性能的提升
[Abstract]:In recent years, with the popularity of smart phones, tablets and other multimedia mobile devices, the scale of the network is expanding, and the mobile data services are growing exponentially. In order to solve this problem, a new network architecture, Heterogeneous Network (HetNet), has gradually become a research hotspot. The network is composed of macro base station cells and small cells deployed within the coverage of macro base station cells. Compared with the traditional flat network, its topology structure is more hierarchical. These small cells can enhance network capacity and realize network data shunting to solve blind areas, hot spots and weak coverage problems, so that operators can provide users with better wireless broadband voice and data industry at a lower cost. Business.
In this paper, the interference management, user connection and self-organizing technologies in HetNet are studied, and the corresponding innovative solutions are proposed. The performance of the proposed algorithm is proved by theoretical analysis and computer simulation.
1) an interference management scheme based on dynamic resource allocation is proposed in hybrid hierarchical heterogeneous networks.
In order to reduce the pressure of Operations and Management Entity (OM), the problem is divided into two parts: interference coarse tuning based on subcarrier allocation and interference fine tuning based on power control.
Secondly, OM uses discrete stochastic approximation algorithm to search the optimal set of subcarriers for all users to minimize the total network interference. For fine-tuning interference, low-power base stations use Carlyle bargaining algorithm to adjust user power and ultimately optimize local revenue. This algorithm converts vector optimization into line optimization. Property optimization has low algorithm complexity.
Finally, the performance of the proposed jamming management scheme is verified by comparing the discrete stochastic approximation algorithm and Carlyle bargaining algorithm with the existing algorithms.
2) a user connection scheme for joint resource allocation in distributed hierarchical heterogeneous networks is proposed.
Firstly, the characteristics of distributed hierarchical heterogeneous networks are analyzed, and the available resources of low power base stations are described. The optimization objective is derived by the minimum latent delay fairness function, which guarantees fairness between users and optimizes the network transmission rate.
Secondly, a user connection model for joint resource allocation is established. The constraints of the model are energy saving and interference reduction.
Thirdly, a user connection and resource allocation scheme based on three-stage search algorithm is proposed. To achieve Pareto optimization, the algorithm consists of three stages: first, searching solutions satisfying the supporting non-dominant poles; second, searching solutions satisfying the supporting non-dominant poles and the supporting non-dominant points; and finally, in the space where the solutions are formed in the first two stages, the root is found. According to the system requirements, the optimal solution of the system is found from the solution set.
Finally, the performance of the proposed scheme and the existing schemes is verified by simulation.
3) a resource allocation scheme based on multi-dimensional factors in self-organizing hierarchical heterogeneous networks is proposed.
Firstly, a resource self-configuration model of hierarchical heterogeneous networks is established according to three factors: energy efficiency, transmission power consumption and stability. Resource allocation includes two parts: user connection and power value setting.
Secondly, the algorithm of user selection and power allocation is designed step by step, and the corresponding parameters of user connection and power allocation are respectively designed. To further enhance the self-organizing function of the base station, a joint execution scheme of user selection and power allocation is designed.
Finally, the performance of self organizing hierarchical heterogeneous network is verified by simulation.
【学位授予单位】：北京邮电大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.5

【共引文献】