D2D技术在LTE-A系统中的应用

Device-to-Device（D2D）是一种在LTE-A系统中通过重用小区内宏蜂窝用户的资源来实现端到端通信的新型技术。本文从实际应用的角度出发,首先对D2D技术的原理和应用进行了分析,然后讨论D2D技术应用于LTE-A系统中的优缺点,接着通过仿真验证了D2D技术在LTE-A系统中的优势。最后阐述了D2D技术在LTE-A系统中应用可研究的方向及技术展望。     

D2D通信中Chief UE应用的研究

Chief UE的作用是辅助实现D2D通信与蜂窝网络通信更好地无缝切换并且提高通信的质量。对Chief UE的概念进行了详细描述,并且对于其在切换中的作用进行了相应的阐述和论证:在传统D2D通信的基础上,定义了其中一个性质稳定良好的UE为Chief UE,进行D2D连接的内部管理和通信,并且在需要切换时,能够进行通行保持直到整个通信切换的完成和结束。将具有Chief UE的D2D切换同不具有Chief UE的D2D切换进行了相应的对比和论述,以更好地论证Chief UE存在的必要性。     

Device-to-Device通信的无线资源管理研究

在IMT-Advanced蜂窝网络中部署设备至设备(D2D:Device-to-Device)通信是当前无线领域内的一个研究热点,其主要的困难在于控制D2D与蜂窝系统间的干扰。D2D的无线资源管理机制和算法是实现系统间干扰协调的关键因素之一。文章从功率控制、资源调度和模式选择3个方面,介绍了D2D无线资源管理研究领域的最新成果和进展,并对未来发展方向进行了分析展望。     

Energy-Efficient Resource Allocation for Heterogeneous Network with Grouping D2D

In this paper,a new communication model is built named grouping D2D(GD2D).Different from the traditional D2D coordination,we proposed GD2D communication in licensed and unlicensed spectrum simultaneously.We formulate a resource allocation problem,which aims at maximizing the energy efficiency(EE)of the system while guaranteeing the quality-of-service(Qos)of users.To efficiently solve this problem,the non-convex optimization problem is first transformed into a convex optimization problem.By transforming the fractional-form problem into an equivalent subtractive-form problem,an iterative power allocation algorithm is proposed to maximize the system EE.Moreover,the optimal closedform power allocation expressions are derived by the Lagrangian approach.Simulation results show that our algorithm achieves higher EE performance than the traditional D2D communication scheme.     

5G网络中DR-OC型D2D通信收益模型及定价研究

Device-to-Device(D2D)通信是下一代(5G)移动网络的重要组成部分。D2D设备间在不依赖基站的情况下直接进行数据传输,并通过重复使用蜂窝小区的频率资源从而提高移动通信系统的容量。为了激励蜂窝网络用户参与到D2D通信,运营商对D2D通信的定价是一个很关键的问题。文中首先介绍了D2D的基本概念及其四种主要类型,并就其中DR-OC型D2D通信定价提出了运营商和D2D设备的收益模型,然后仿真分析了网络中谱单价和奖励带宽对双方收益的影响。仿真结果显示运营商可以通过调整奖励带宽来协调双方收益以激励更多的用户参与到D2D通信。     

异构网络中基于能效优化的D2D资源分配机制

针对异构网络中D2D通信复用蜂窝用户频谱时存在的频谱分配问题,该文提出一种基于改进离散鸽群优化(PIO)算法的D2D通信资源分配机制。通过设置信干噪比(SINR)门限值来保证用户的通信服务质量(QoS),采用功率控制算法为用户设置发射功率,使用基于运动权值的二进制离散鸽群优化(MWBPIO)算法为D2D用户进行资源分配,并将D2D通信技术与中继技术进行有效结合,为边缘用户建立D2D中继链路,保证边缘用户的通信质量,最大化系统性能目标。仿真结果表明,该方案有效抑制了异构通信系统中引入D2D用户后导致的干扰问题,提高了边缘用户的通信质量和系统的频谱利用率以及系统的能效。     

毫米波D2D通信上下行链路吞吐量优化方案

5G通信技术中终端直通(D2D通信)的功率分配是近期研究的热点,为了提升系统容量和频谱利用率,将毫米波与D2D通信技术结合,在此技术中,针对28GHz频段上行链路及下行链路蜂窝网络中的D2D资源分配进行了研究,将其系统总吞吐量达到最大化算法进行优化。首先,推导出每个D2D对所对应的准入集,其次,在考虑每个D2D对用户以及蜂窝用户功率控制情况下,分别求出上行链路及下行链路中的吞吐量,最后,在保证D2D对总吞吐量最大化前提下将蜂窝用户信道分配给D2D对。仿真结果表明,所提出的方案可以提高系统的吞吐量。     

Survey of software defined D2D and V2X communication

The related D2D (device-to-device) and V2X (vehicle-to-everything) are regarded as vital components of 5G communication system,which providing alternative network services and multiple application services for cellular network.In the meanwhile,SDN (software defined networking) can improve the compatibilities and flexibilities of D2D and V2X.SD-D2D (software defined D2D communication) and SD-V2X (software defined V2X communication) technologies were reviewed.Based on their similarities and respective characteristics,their state-of-arts and architectures were reviewed accordingly,and the key technologies such as D2D location/discovery management,D2D routing control,D2D flow table management,V2V path scheduling,and V2V path recovery were analyzed.Finally,it was pointed out that the SD-D2D architecture was approaching mature and the SD-V2X framework had been preliminarily determined,the existing problems of interference management,mobile management and routing management in D2D/V2X communication could be effectively solved.Furthermore,it was also pointed out that the disconnection between the existing SD-D2D/V2X studies and the actual application needed to be overcome.     

Power allocation criteria for distributed antenna systems with D2D communication

In this paper, we discuss four different optimization problems for distributed antenna systems (DAS) with and without D2D communication, respectively. The first and the third problems are maximizing spectral efficiency (SE) and energy efficiency (EE) of the DAS with D2D communication on the conditions of the minimum SE of DAS as well as D2D pair, the maximum transmit power of each remote access unit (RAU) and maximum transmit power of D2D transmitter. The second and the forth problems are maximizing SE of the DAS on the conditions of the minimum SE as well as the maximum transmit power of RAUs. We exploit the sub-gradient iteration method to obtain the optimal power allocation and summarize optimal power allocation algorithms for the first and second problems. We exploit fractional programming method to investigate the third and fourth problems and develop corresponding optimal power allocation algorithms. Simulation results demonstrate the effectiveness of the proposed power allocation algorithms and show the SE and EE of the DAS by using D2D communication are much better than DAS without D2D communication.     

基于可变距离的车联网D2D通信连接选择

车联网是移动互联网的延伸,其中基站协作的D2D通信适用于车间交通消息的短距离无线传播.针对车辆快速移动导致的通信链路动态性,提出了一种基于可变距离的D2D连接选择方法.通过选择行车道及车间距离参数,估计D2D连接对的信道质量,推导了D2D连接选择的优先指数,并基于该优先指数建立D2D通信链路进行交通消息传播.仿真结果显示,所提方法在D2D连接的生存时间、传输效率方面得到提高,同时降低了D2D通信的中断概率,提升了车辆间通信可靠性.     

基于LTE D2D技术的车联网通信架构与数据分发策略研究

基于5G通信技术的车联网面临高速率、低时延、高可靠性和大量流媒体数据分发等需求,提出了一种基于LTE D2D的车联网通信架构,设计基于运动一致性的车辆分簇算法,有效增加持续D2D通信时间,提高通信可靠性;其次,针对簇内车辆的流媒体数据分发,提出一种带时延约束的D2D协作中继转发策略,设计最优中继选择算法,大幅提高数据传输速率,提升网络吞吐量。     

一种基于Android和JXTA协议模型的无线D2D通信技术

移动通信系统的快速发展使得频谱资源日益紧缺。D2D通信是一种在系统的控制下,允许终端之间通过复用小区资源直接进行通信的新型技术。它能减少小区网络的负载,还能支持新型的小范围点对点数据通信,是未来绿色通信发展的趋势。针对这一新型的通信技术,提出了基于Android OS平台,以JXTA协议为模型的无线D2D通信技术,使得移动终端之间能够进行通信与资源共享,并通过网络实验验证了其有效性。     

Power allocation and relay selection for network-coded D2D communication underlay heterogeneous cellular networks

Underlay device-to-device (D2D) communication is an attractive technology enabling nearby cellular users to communicate with each other directly in order to increase data rate and spectral efficiency. The current cellular heterogeneous networks consist of macrocell base stations and small cell base stations with different transmit powers and coverage areas. Femtocell is the most popular small cell which is expected to be utilized in dense and ultra-dense scenarios in the future. Network coding in relay-assisted multi-hop communications improves achievable transmission rate and coverage of D2D communications. In this paper, two-hop random linear network coding network in cooperative D2D communication (RLNC-CDC) is considered. We propose to use femtocell base station (FBS) as a relay. We assume that the D2D pair and relay operate in the frequency band which is allocated to femtocell network. Therefore, there would be interference from the relay node and the D2D communication on the femtocell network users. To reduce the interference, the sum of transmit powers of the D2D pair and selected relay FBS should be minimized in a way that the highest transmission rate for the D2D pair is achieved. The constraints on the bounds of transmit powers of the D2D and relay node as well as the minimum required transmission rate for D2D communication are considered and the optimum solution is obtained. Simulation results indicate that the proposed RLNC-CDC achieves higher data rate and smaller outage probability than the direct D2D transmission.     

D2D通信资源调度研究现状综述

终端直通技术(D2D)是一种终端在基站控制下直接进行通信而不需要基站转发的新型通信技术。D2D引入LTE-A蜂窝系统虽然可以带来吞吐量和频谱效率的提升,但是也会带来很大的干扰。综合近些年来的研究成果,合理的资源调度算法成为降低干扰,提升系统性能的关键。首先,描述了D2D通信技术引入LTE-A蜂窝网络后的系统干扰模型。然后,从模式选择、资源分配和功率控制三个方面综述了目前国内外文献关于资源调度算法的研究成果。     

基于自私行为分析的超密集D2D中继选择算法

在超密集D2D通信中,目前的中继选择方案主要假定中继设备具有主动意愿参与数据转发,但部分理性中继设备出于自身考虑,可能会存在时延或拒绝转发的自私行为,进而影响用户体验效果.从中继设备自私行为角度出发,提出了D2D通信中自私中继设备识别方法,进而提出了基于自私行为分析的超密集D2D中继选择算法.首先,定义了联合兴趣度、转...     

中继协同D2D通信的能效优化

针对D2D中继通信中D2D设备电池容量受限问题,本文提出了一种逐步优化功率控制和中继选择从而最大化系统能量效率的方法.首先,在满足蜂窝链路最小数据速率的条件下,将功率控制问题建模为一个非线性规划问题,并求解出D2D发射机的最优发射功率;然后,分别利用发送节点与接收节点的邻域为半径建立节点均匀分布的球状模型;其次,基于路...     

UAV-assisted multi-hop D2D relaying for communication in large disaster area

An unmanned aerial vehicle (UAV)-assisted communication is a promising technique for enabling ground users in a non-functional area (NFA) or disaster area to communicate. All the base stations in the disaster area may be partially or fully damaged due to the natural calamity. Device-to-device (D2D) communication can be a viable solution for immediate connection between users in an NFA. We propose a UAV-assisted multi-hop D2D communication following a hybrid power-time switching (PTS) in this paper. Moreover, a D2D user of a cluster can communicate with another D2D user in a different cluster through UAVs. However, D2D users can harvest energy from their respective ad hoc energy stations and forward the information to the nearby D2D user following a hybrid PTS-based strategy. We propose a time frame for the same and show a node-based energy harvesting strategy. The expressions of outage probability, throughput, end-to-end energy consumption, and energy efficiency are developed for the Rician and Nakagami-m faded channel. The impact of several network parameters such as energy harvesting factor, energy harvesting efficiency, and fading parameter on the network performance is also indicated.     

全负载蜂窝网络下多复用D2D通信功率分配算法研究

针对全负载蜂窝网络中D2D通信的功率分配问题,该文提出了一种基于非合作完全信息博弈纳什均衡解的多复用D2D通信功率分配算法。以优先保证蜂窝用户通信质量与D2D用户接入率为前提,设置D2D通信系统上行链路帧结构,之后建立非合作完全信息博弈系统模型,引入定价机制到功率分配博弈模型中并分析纳什均衡解的存在性与唯一性,最后给出该模型的分布式迭代求解算法。仿真结果表明,随着D2D用户复用数量的增加,该算法在提升系统吞吐量的同时,能有效地控制系统内部干扰,大幅度降低系统总能耗。     

Media Independent Mobility Management for D2D Communications over Heterogeneous Networks (HetNets)

The rapid growth of traffic demand and innovation of mobile networks have pushed the current communication infrastructure to provide a tight integration of different wireless technologies. On the one hand, all user connections are expected to be heterogeneous in future networks and thus an intelligent mobility management is essential to satisfy the requirements of lower latency, less power consumptions and last but not least possible uninterrupted ongoing session when a User Equipment (UE) moves across network boundaries. On the other hand, Device-to-Device (D2D) communication as a revolutionary technology to enhance network performance has shown a great potential in dominating future communication market. Consequently, in this paper, we investigate the mobility management problem for D2D communications in heterogeneous networks. We leverage on IEEE 802.21 Media Independent Service (MIS) and propose a new framework, so-called enhanced version of IEEE 802.21 MIS that supports D2D communication (E-MIS-D2D) to enhance D2D mobility experience over heterogeneous networks. The E-MIS-D2D is a network assisted and initiated architecture, in which a load-aware mode selection algorithm is also proposed for selecting the transmission mode between D2D and non-D2D modes. Through extensive simulations, we validate that the proposed method outperforms the existing methods in terms of packet loss ratio, average throughput, latency, bandwidth usage and load rate of eNB.

     

基于信干噪比的D2D通信功率控制与资源分配

为了优化长期演进(LTE)系统引入设备直传(D2D)通信后带来的同频干扰、系统边缘用户性能恶化问题,提出一种基于信干噪比(SINR)的多小区D2D通信资源分配方案,通过调整信干噪比阈值将部分蜂窝用户(CU)转化为D2D用户并释放频谱资源进而获得较佳的资源分配策略,同时提出一种基于小区间D2D竞争机制的配置算法有效降低小区间干扰.仿真表明,算法能够有效提升系统容量,并提升小区边缘D2D用户公平性.