D2D通信远近效应研究
发布时间：2018-10-20 09:24
【摘要】：摘要：移动通信技术经历了第一代频分多址通信、第二代时分复用通信、第三代码分多址通信,现在已经步入到第四代LTE (Long Term Evolution)移动通信时代。移动通信给人们的生活带来了巨大便利,但同时也面临着用户量激增系统容量有限、基站负荷过重、无线电频谱资源日益稀缺等问题。随着各种移动应用的增加,移动终端的耗电量也在逐步增大。正是在这种情形下,D2D (Device-to-Device)通信应运而生。D2D通信是一种设备到设备的短距离直通技术,用户之间传输数据信息不再通过基站中转而直接进行通信,减轻了基站的负荷,降低了终端的发射功率,增加了频谱利用率。D2D通信虽然有许多优点,但也存在着远近效应问题影响了D2D通信的质量。 本文针对D2D通信模式下远近效应现象进行研究,分析影响远近效应的因素以及在不同影响因素作用下的仿真情况。由于D2D通信技术属于LTE通信系统范畴,首先介绍了LTE通信的需求、技术特点、协议架构以及使用到的先进技术等相关知识。接着重点介绍了D2D通信的架构、建立流程以及和蜂窝通信之间的干扰等。由于CDMA (Code Division Multiple Access)系统多址干扰的存在,远近效应现象严重影响了CDMA系统的性能,对LTE系统D2D通信模式也将产生不可忽略的影响。LTE系统采用的是正交频分复用OFDM (Orthogonal Frequency Division Multiplexing)多载波调制方式。由于D2D通信是基于LTE功能流程上的,远近效应现象在D2D通信模式中产生的情形就会有所不同。目前抑制远近效应的方法有功率控制、多用户检测、自适应干扰消除以及跳频等。本文在介绍无线电波传播模型和无线信道模型基础上,选取城市微小区(Urban Micro)信道模型作为仿真信道模型,并搭建了基于D2D通信的仿真系统。通过在不同接收功率、不同时间偏移量、不同频率偏移量、不同资源块间隔等条件下对D2D远近效应进行了仿真分析并给出了结论。文章最后将K-means聚类算法应用到D2D通信远近效应场景中进行研究,根据不同的聚类数以及每个聚类中不同的同时发送信号的用户数进行仿真分析并得出结论。
[Abstract]:Absrtact: the mobile communication technology has experienced the first generation frequency division multiple access communication, the second generation time division multiplexing communication, the third generation code division multiple access communication, now has entered the fourth generation LTE (Long Term Evolution) mobile communication era. Mobile communication brings great convenience to people's life, but it also faces some problems such as the limited capacity of the user surge system, the overload of the base station, the increasingly scarce radio spectrum resources, and so on. With the increase of various mobile applications, the power consumption of mobile terminals is gradually increasing. It is in this situation that D2D (Device-to-Device) communication emerges as the times require. D2D communication is a kind of short-distance direct communication technology from equipment to equipment. The data information transmitted between users is no longer communicated directly through the base station, which reduces the load of the base station. The transmission power of the terminal is reduced and the spectrum efficiency is increased. Although D2D communication has many advantages, it also has the problem of near-far effect which affects the quality of D2D communication. In this paper, the near-far effect in D2D communication mode is studied, and the factors that affect the near-far effect and the simulation under different influence factors are analyzed. As D2D communication technology belongs to LTE communication system, this paper first introduces the requirements, technical characteristics, protocol architecture and advanced technologies used in LTE communication. Then, the architecture of D2D communication, the flow of establishment and the interference between D2D communication and cellular communication are introduced. Due to the existence of multiple access interference (mai) in CDMA (Code Division Multiple Access) system, the near-far effect seriously affects the performance of CDMA system. The D2D communication mode of LTE system will also be affected. The LTE system adopts orthogonal frequency division multiplexing (OFDDM) OFDM (Orthogonal Frequency Division Multiplexing) multicarrier modulation. Because D2D communication is based on LTE function flow, the phenomenon of near-far effect will be different in D2D communication mode. At present, power control, multi-user detection, adaptive interference cancellation and frequency hopping are used to suppress the near-far effect. Based on the introduction of radio wave propagation model and wireless channel model, this paper selects the (Urban Micro) channel model of urban microcell as the simulation channel model, and builds a simulation system based on D2D communication. The D2D far and near effect is simulated and analyzed under different receiving power, different time offset, different frequency offset and different resource block spacing, and the conclusion is given. Finally, the K-means clustering algorithm is applied to the D2D communication near and far effect scene. The simulation analysis is carried out according to the different clustering number and the number of users who send different signals at the same time in each cluster, and the conclusion is drawn.
【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】：TN929.5
本文编号：2282719
[Abstract]:Absrtact: the mobile communication technology has experienced the first generation frequency division multiple access communication, the second generation time division multiplexing communication, the third generation code division multiple access communication, now has entered the fourth generation LTE (Long Term Evolution) mobile communication era. Mobile communication brings great convenience to people's life, but it also faces some problems such as the limited capacity of the user surge system, the overload of the base station, the increasingly scarce radio spectrum resources, and so on. With the increase of various mobile applications, the power consumption of mobile terminals is gradually increasing. It is in this situation that D2D (Device-to-Device) communication emerges as the times require. D2D communication is a kind of short-distance direct communication technology from equipment to equipment. The data information transmitted between users is no longer communicated directly through the base station, which reduces the load of the base station. The transmission power of the terminal is reduced and the spectrum efficiency is increased. Although D2D communication has many advantages, it also has the problem of near-far effect which affects the quality of D2D communication. In this paper, the near-far effect in D2D communication mode is studied, and the factors that affect the near-far effect and the simulation under different influence factors are analyzed. As D2D communication technology belongs to LTE communication system, this paper first introduces the requirements, technical characteristics, protocol architecture and advanced technologies used in LTE communication. Then, the architecture of D2D communication, the flow of establishment and the interference between D2D communication and cellular communication are introduced. Due to the existence of multiple access interference (mai) in CDMA (Code Division Multiple Access) system, the near-far effect seriously affects the performance of CDMA system. The D2D communication mode of LTE system will also be affected. The LTE system adopts orthogonal frequency division multiplexing (OFDDM) OFDM (Orthogonal Frequency Division Multiplexing) multicarrier modulation. Because D2D communication is based on LTE function flow, the phenomenon of near-far effect will be different in D2D communication mode. At present, power control, multi-user detection, adaptive interference cancellation and frequency hopping are used to suppress the near-far effect. Based on the introduction of radio wave propagation model and wireless channel model, this paper selects the (Urban Micro) channel model of urban microcell as the simulation channel model, and builds a simulation system based on D2D communication. The D2D far and near effect is simulated and analyzed under different receiving power, different time offset, different frequency offset and different resource block spacing, and the conclusion is given. Finally, the K-means clustering algorithm is applied to the D2D communication near and far effect scene. The simulation analysis is carried out according to the different clustering number and the number of users who send different signals at the same time in each cluster, and the conclusion is drawn.
【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】：TN929.5
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本文编号：2282719
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