无线通信系统中的中继选择策略研究

发布时间：2018-06-13 13:35

本文选题：无线通信 + 协作分集　；参考：《北京交通大学》2014年硕士论文

【摘要】：目前,协作中继技术在无线通信领域是一个前沿的研究方向,它可以克服MIMO (Multiple-Input Multiple-Output)技术因受制于体积及功率等条件限制而无法应用于实际无线终端中的难题。其基本思想是配置单天线的多个用户通过共享彼此的天线,从而形成虚拟的MIMO系统。协作中继技术可以有效地降低无线信道中的衰落特性以及链路不稳定性造成的影响,提高无线通信系统的频谱效率以及数据传输速率。本文对无线单向中继系统中的中继伙伴选择方案和双向中继系统中的中继伙伴选择方案这两种目前协作通信的研究方向进行了研究,本文的主要研究内容和创新点如下： 1.在研究无线单向中继系统中的协作中继选择方案中,针对放大转发模式下的单向中继协作系统,结合已有的协作中继模型,重点探讨了移动中继节点选择的相关内容,提出了一种动态中继选择策略。在提出的中继选择策略中,假设无线协作系统的总功率固定,并且节点之间的链路信道状态信息(Channel State Information)可获知,当用户进入路边AP(Access Point)的覆盖范围时,通过将各中继的状态值与设定的最小阈值进行比较来剔除多余中继节点。此外,针对中继系统的功率资源问题,分析了带宽归一化系统容量、系统信噪比以及用户的发射功率因子之间的关系。通过模拟实际高速公路场景建模,对提出的相关算法进行仿真实验,结果验证了本文提出的动态中继选择策略能够有效地降低系统的中断概率,同时还能保持系统容量基本不变。 2.在研究无线双向中继系统中的协作伙伴选择方案中,通过对目前的双向中继选择研究进展进行归纳总结,基于现有的双向中继选择算法,改进了一种双向中继选择算法。本文还对双向中继系统中的功率资源分配问题进行研究,通过对相关文献的查阅,改进了一种基于加权总速率最大化的功率分配策略。经过合理的仿真设置,对改进的双向中继算法及功率分配策略都进行了多次仿真实验。通过与现有的双向中继选择算法比较,结果显示改进后的双向中继选择算法可以在一定情况下获得更突出的性能表现,此外,通过与现有功率分配策略比较,结果显示本文提出的功率分配策略在一定情况下能够提高系统传输总速率。
[Abstract]:At present, cooperative relay technology is a frontier research field in wireless communication field. It can overcome the problem that MIMO Multiple-Input Multiple-Output technology can not be applied to practical wireless terminals because of the constraints of volume and power. The basic idea is to form a virtual MIMO system by sharing each other's antennas with multiple users with a single antenna. Cooperative relay technology can effectively reduce the fading characteristics in wireless channels and the impact of link instability, and improve the spectral efficiency and data transmission rate of wireless communication systems. In this paper, two kinds of cooperative communication research directions, relay partner selection scheme in wireless one-way relay system and relay partner selection scheme in two-way relay system, are studied. The main contents and innovations of this paper are as follows: 1. In the research of cooperative relay selection scheme in wireless unidirectional relay system, aiming at the one-way relay cooperation system in the mode of amplification and forwarding, combined with the existing cooperative relay model, this paper focuses on the selection of mobile relay nodes. A dynamic relay selection strategy is proposed. In the proposed relay selection strategy, it is assumed that the total power of the wireless collaboration system is fixed and that the link channel state information between nodes can be obtained when the user enters the coverage of the roadside APN access point, Redundant relay nodes are eliminated by comparing the state values of each relay with the set minimum threshold. In addition, aiming at the power resource problem of relay system, the relationship between bandwidth normalized system capacity, system SNR and user transmit power factor is analyzed. By simulating the actual freeway scene modeling and simulating the related algorithms, the results show that the proposed dynamic relay selection strategy can effectively reduce the outage probability of the system. At the same time can also maintain the system capacity is basically unchanged. 2. In the research of cooperative partner selection scheme in wireless bidirectional relay system, a bidirectional relay selection algorithm is improved based on the existing bidirectional relay selection algorithm by summarizing the current research progress of bidirectional relay selection. In this paper, the power resource allocation problem in bidirectional relay system is studied, and a power allocation strategy based on weighted total rate maximization is improved by consulting related literatures. After reasonable simulation, the improved bidirectional relay algorithm and power allocation strategy are simulated many times. By comparing with the existing bidirectional relay selection algorithm, the results show that the improved bidirectional relay selection algorithm can obtain more outstanding performance under certain circumstances, in addition, by comparing with the existing power allocation strategy, The results show that the proposed power allocation strategy can improve the total transmission rate under certain conditions.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN92

【参考文献】