LTE-Advanced

摘要： Nowadays,video streaming applications are becoming one of the tendencies driving vehicular network users.In this work,considering the unpredictable vehicle density,the unexpected acceleration or deceleration of the different vehicles included in the vehicular traffic load,and the limited radio range of the employed communication scheme,we introduce the“Dynamic Vehicular Clustering”(DVC)algorithm as a new scheme for video streaming systems over vehicular ad-hoc networks(VANET).The proposed algorithm takes advantage of the small cells concept and the introduction of wireless backhauls,inspired by the different features and the performance of the Long Term Evolution(LTE)-Advanced network.Vehicles are clustered together to form dynamically ad-hoc sub-networks included in the vehicular network.The goal of our clustering algorithm is to take into account several characteristics,such as the vehicle’s position and acceleration to reduce latency and packet loss.Therefore,each cluster is counted as a small cell containing vehicular nodes and an access point that is elected regarding some particular specifications.Based on the exceptional features of the LTE-Advanced network(small cells and wireless backhauls)the DVC algorithm is a promising scheme for video streaming services over VANET systems.Experiments were carried out with a virtual topology of the VANET network created with four clusters to implement the DVC algorithm.The results were compared with other algorithms such as Virtual Trust-ability Data transmission(VTD),Named Data Networking(NDN),and Socially Aware Security Message Forwarding(SASMF).Our algorithm can effectively improve the transmission rate of data packets at the expense of a slight increase in end-to-end delay and control overhead.

摘要： 近年来,随着移动通信技术的发展,无线通信技术越来越成熟,作为全球的新兴技术,大大提高了数据信息传输效率,在农业生产中发挥着巨大作用.无线通信技术因成本造价低廉、设备灵活性高和施工周期短等优势,正逐步取代有线技术,渗透到农业领域的每一个阶层.为此,以LTE-Advanced和微粒群算法为通信路径搭建了采摘机器人无线通信系统,采用高效的质效控制和通信协议,很大程度提高了网络可靠性和稳定性.测试结果表明:该无线通信系统数据传输率较高、丢包率为0,符合采摘机器人无线通信系统的设计要求,对实现果实采摘无人化具有十分重要的意义.

摘要： CoMP(协作多点传输技术)通过处于不同地理位置的多个传输点之间的协作来避免相邻基站之间的干扰或将干扰转换为对用户有用信号,以协作的方式实现用户性能的改善.本文在介绍CoMP基本原理和两大主流的技术方向的基础上,对CoMP应用方案进行了研究,对CoMP技术的应用有较好的实践意义.

摘要： In the age of Big Data,faced with massive and complex structured,semi-structured and unstructured data,traditional signaling monitoring system has been unable to quickly and accurately classify,handle and store information contained massive data.To resolve these problems,a user behavior analysis system on Uu interface in LTE-Advanced network based Hadoop technology platform and Support Vector Machine classification algorithm is proposed.And then,system architecture of user behavior analysis system and implement of SVM classification algorithm on Hadoop platform are illustrated.Meanwhile,through testing present network environment on Uu interface.The testing results prove the system produces the desired effect and has crucial promotion significance of user preferences analysis and precision marketing.%大数据时代,面对海量且复杂的结构化、半结构化和非结构化数据,传统的信令监测分析系统无法快速准确地分类、处理以及存储海量数据中包含的信息.针对这些问题,提出了一种基于Hadoop系统技术平台和支持向量机(Support Vector Machine,SVM)分类算法的LTE-Advanced网络Uu接口用户行为分析系统.对用户行为分析系统的系统架构、在Hadoop平台下数据挖掘分类算法SVM的实现进行了详细阐述,并通过Uu接口进行了现网测试,测试结果表明,提出的用户行为分析系统达到了预期的效果,对用户偏好分析以及精准营销具有推广意义.

摘要： Through analyzing the random access model of slotted access based channel access control protocol (SCACP) in LTE-Advanced system,an optimization algorithm for access frame length selection based on slotted access was proposed.The dynamic frame length selection in slotted access based on network real-time access load was realized.Moreover,the optimized access frame length was more suitable for current access load than before.It could ensure a high success rate of access,eliminate the unnecessary access delay and decrease the number of retransmissions to some extent.The simulation results demonstrate that the proposed dynamic frame length selection algorithm is more effective and practical.%通过分析LTE-Advanced系统中基于时隙接人信道控制协议(SCACP)的随机接入模型,提出一种时隙接入方法中接入帧长的优化算法.利用网络实时接入负载实现时隙接人中动态帧长的选择,使得优化后的接入帧长更适合当前接入负载,保障了较高的接入成功率,消除了不必要的接入时延,还在一定程度上减少了前导重传次数.最后通过仿真验证了所提动态帧长选择算法的有效性和实用性.

摘要： LTE-Advanced信令消息的加解密过程测试和验证是空口信令测试过程中最为基础和重要的过程,其目的是保证空口协议信令能够快速、准确、有效地被解析处理,为空口业务监测提供可能.本文主要针对空口鉴权消息信令的加解密过程进行研究,设计实现一种加解密过程测试方法和硬件平台技术,保证能够快速有效地实现空口密文信令消息解密测试和验证.测试结果验证了该方案的有效性.

摘要： 由于移动通信的快速发展,市场不断提出更高的需求和更多的应用,为满足高峰值速率和长频率带宽的要求,文章通过引入载波聚合技术,在不对现有LT E网络架构进行大改动的前提下,将离散的频谱资源整合在一起,获得类似连续带宽所带来的最大频谱利用率,实现上下行峰值速率的极大提高,并确保用户移动切换业务和原有网络覆盖不受影响.

摘要： 在LTE-Advanced(长期演进技术升级版,简写为LTE-A)中,接入中继节点的前向和后向链路之间存在着链路质量间的不匹配问题,首先分析了当缓冲区上溢或者下溢发生时,缓冲区的大小对整个系统的影响。然后基于仿真结果,得出中继节点缓冲区大小能够有效的影响服务用户的吞吐量性能,并且着重研究了具有有限缓冲区大小中继节点的LTE-A辅助系统的性能。最后,阐述了对于LTE-A系统中不同的中继节点,尤其是当缓冲区进入上溢或者下溢状态时,缓冲区的大小设置对系统整体性能起着至关重要的作用。

摘要： 通过分析LTE-Advanced系统中机器类通信(MTC)设备的随机接入效率,提出一种负载反馈控制的改进方法.利用前导状态信息估计当前负载并预测下一接入时隙的负载,然后基于负载的变化调整MTC设备接入控制参数,减少了大量MTC设备突发性接入对人与人(H2H)设备的影响,能有效降低重传次数,提升接入成功率.通过仿真分析说明所提方案有效可行,具有良好性能.

摘要： 数据业务的爆发式增长，更宽频谱的需求成为了影响从LTE向LTE-Advanced演进的最重要因素。为此河南公司开展了三载波聚合的性能测试研究，包括基于2.6GHz的D频段、F+D频段的载波聚合，以及室内的E频段，速率已经达到220Mbps。TDD-LTE的三载波聚合技术在将多个载波聚合成一个更宽的频谱的同时会造成不必要的重传，并且具有较大的HARQ反馈时延，制约了载波聚合技术对于用户感知的进一步改善。因此，本文将主要以现网分析的方式，讨论如何解决LTE-Advanced系统中TDD-LTE三载波聚合技术所面临的现网的问题。实测结果表明三载波聚合技术后不仅大幅度提升了传输速率，还能有效改善网络质量，提升吞吐量，使网络负载更加均衡，尤其是在负载较重的时候效果会更明显。%With theexplosive growth of data services,the demand for a wider spectrum has become the most important factor that affects the evolution from LTE to LTE-Advanced. For this purpose,the company carried out the performance test of three carrier aggregation,including 2.6GHz based D band,F+D band carrier aggregation,as well as the indoor E band,the rate has reached 220Mbps.Tdd-lte three carrier aggregation technology in multiple carrier polymerization into a wider spectrum of at the same time can cause unnecessary retransmissions,and has larger HARQ feedback delay,which restricts the carrier polymerization technology for the further improvement of the user perception.Therefore, this article will mainly take the present network analysis method,discusses how to solve the LTE-Advanced system in the TDD-LTE three carrier aggregation technology is faced with the problem of the current network.Experimental results show that after the carrier aggregation technology not only greatly enhance the transmission rate,can effectively improve the network quality,throughput,make the network load more balanced,especially in the load heavier when the results will be more obvious.

摘要： 下行增强MIMo是LTE-Advanced的关键技术之一，文章讨论了LTE R8和R9的多用户MIMO的传输模式，并且就LTE-Advanced中的多用户MIMO的主要问题进行了讨论，比较了各种可能的导频设计，下行控制信令、反馈及增强的码本设计方法，探讨了多用户MIMO适用的场景以及每个用户支持多于两个layer的可能性，并介绍了标准化进展情况。

摘要： 下行增强MIMo是LTE-Advanced的关键技术之一，文章讨论了LTE R8和R9的多用户MIMO的传输模式，并且就LTE-Advanced中的多用户MIMO的主要问题进行了讨论，比较了各种可能的导频设计，下行控制信令、反馈及增强的码本设计方法，探讨了多用户MIMO适用的场景以及每个用户支持多于两个layer的可能性，并介绍了标准化进展情况。

摘要： 下行增强MIMo是LTE-Advanced的关键技术之一，文章讨论了LTE R8和R9的多用户MIMO的传输模式，并且就LTE-Advanced中的多用户MIMO的主要问题进行了讨论，比较了各种可能的导频设计，下行控制信令、反馈及增强的码本设计方法，探讨了多用户MIMO适用的场景以及每个用户支持多于两个layer的可能性，并介绍了标准化进展情况。

摘要： 下行增强MIMo是LTE-Advanced的关键技术之一，文章讨论了LTE R8和R9的多用户MIMO的传输模式，并且就LTE-Advanced中的多用户MIMO的主要问题进行了讨论，比较了各种可能的导频设计，下行控制信令、反馈及增强的码本设计方法，探讨了多用户MIMO适用的场景以及每个用户支持多于两个layer的可能性，并介绍了标准化进展情况。