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1.
D2D技术是一种不需要在基站的帮助就可以进行的通信终端之间的直接通信,实现拓展网络连接和接入方式.因为通信距离短,信道质量很好,D2D可以实现较高的数据速率、较低的时延和较低的功耗;进行终端广泛分布,可以改善覆盖,实现频谱资源的高效利用,能够实现更灵活的网络架构和连接方法,增加链路灵活性和网络可靠性.当下,D2D采用广播、组播以及单播技术手段,未来会发展其增强技术,包括基于D2D的中继技术、多天线技术以及联合编码技术等.  相似文献   

2.
姜鸿强  张晶 《信号处理》2020,36(2):233-239
设备直连(Device-to-Device, D2D)通信技术通过复用蜂窝系统的频谱资源提高频谱利用率,但D2D的引入会给蜂窝系统带来干扰。如何合理地选择D2D/蜂窝通信模式并进行功率优化控制,成为减小D2D和蜂窝系统间干扰、提升网络性能的关键。本文考虑D2D用户复用蜂窝上行链路场景,提出了一种基于距离和联合功率控制的通信模式选择方案。在该方案中,D2D用户和蜂窝用户与基站距离的比值决定了D2D用户是否采用Underlay模式进行通信,进而在约束蜂窝用户和D2D用户发射功率的条件下实现D2D链路和蜂窝链路的联合功率控制,最终推导出能够最大化系统总吞吐量的最优用户功率分配方案。根据仿真结果,本文提出的联合功率控制方案能够在降低系统间干扰的同时有效提高D2D和蜂窝系统的总吞吐量,进而提高了系统的性能。   相似文献   

3.
曹型兵  王伟超 《电讯技术》2017,57(12):1433-1439
为优化蜂窝用户通信与设备直传(D2D)中继通信共存下的同频干扰问题,满足蜂窝用户容量要求,提出了一种基于能效的联合资源分配和功率控制的D2 D中继选择算法.该算法首先对等效D2 D中继链路进行资源分配,减小算法复杂度的同时使得D2 D链路对蜂窝链路产生的干扰最小;然后以资源分配结果和功率控制算法为依据进行中继选择.该方案不仅考虑了D2 D中继链路的能效问题,而且还同时考虑到了对蜂窝链路的干扰问题.通过仿真验证,所提算法不仅能有效提升D2 D中继链路的能效值,同时降低了对蜂窝用户的干扰.  相似文献   

4.
提高蜂窝网络中数据分发效率的D2D协作转发算法   总被引:3,自引:0,他引:3  
Device-to-Device(D2D)通信是一种移动终端在蜂窝通信系统的控制下使用授权频段进行点到点通信的新型技术。通过允许接收终端间的数据转发,D2D通信可以用来提高蜂窝网络中的数据分发效率。现有的终端间转发算法,没有充分考虑D2D链路的差异,很难实现频谱资源的高效利用。为此,该文提出了一种基于多跳中继的D2D协作转发算法,包括多播和单播两个模式。该算法根据D2D链路质量自适应地选择最优的中继、路由及传输跳数,能够充分利用D2D链路的多信道分集增益。仿真结果表明,该文所提出的算法能够显著地提高D2D转发的资源利用率,进而提升数据分发业务的吞吐量。  相似文献   

5.
在包含中继节点的D2D(Device-to-Device)系统中,针对蜂窝链路与D2D链路同时受窃听的问题,提出一种基于链路间干扰辅助的中继D2D系统安全通信方法.首先,确定蜂窝链路与D2D链路上下行发送模式;然后,在基站与中继节点的发送信号中添加人工噪声,协作干扰窃听者;最后,对基站功率分配与D2D功率控制进行了优化,以实现不同类型链路间干扰辅助保障系统安全.仿真结果表明,所提出的安全通信方法在保密速率方面比SVD(Singular Value Decomposition)与ZF(Zero-Forcing)预编码方法提高了1.5bit/s/Hz.  相似文献   

6.
针对D2D蜂窝系统通信安全性受资源限制的问题,考虑到蜂窝链路和D2D链路的同频干扰能够为两者带来安全增益,基于此,提出一种基于安全中断概率的D2D用户接入策略。首先理论分析了蜂窝用户和D2D用户的安全中断概率,并给出了基于安全中断概率最小化的D2D用户功率优化算法。在上述分析的基础上,选择安全中断概率最小的D2D用户接入复用蜂窝用户的无线资源,同时提高D2D通信链路和蜂窝上行链路的安全性。最后,仿真结果证明了所提算法的有效性。  相似文献   

7.
在LTE系统中引入设备直传(D2D)通信技术,会因为D2D用户复用蜂窝用户资源进行通信而产生同频干扰.在现有的干扰协调与资源分配研究中,都需要基站获取各个通信链路的信道状态信息(CSI),但这样无疑会增加基站的信令负担.为减小干扰与基站的信令负担,提出了一种基于用户中断概率的干扰协调与资源分配算法,首先在保证蜂窝用户正常通信的情况下,通过限制D2D用户到基站间的距离来降低干扰;其次通过遍历所有蜂窝用户的频谱资源,选择能使D2D用户的总中断概率最低的频谱资源进行复用.仿真结果表明,所提算法能够在保证蜂窝用户正常通信的情况下,明显降低D2D用户的平均中断概率,同时还能够降低基站信令负担.  相似文献   

8.
D2D通信中联合链路共享与功率分配算法研究   总被引:1,自引:0,他引:1       下载免费PDF全文
针对D2D (Device-to-Device,D2D)通信过程中的资源分配问题,提出一种联合链路共享和功率分配算法.在保证系统内蜂窝用户服务质量(Quality of Service,QoS)需求的前提下,利用系统的信道状态信息,为D2D用户生成一个由蜂窝用户组成的通信链路的候选集合;在通信链路候选集合内使用凸优化方法得到D2D用户最优功率分配策略;最后利用(Kuhn-Munkres,KM)算法求解最大加权二部图匹配(Maximum Weight Bipartite Matching,MWBM)问题,为D2D用户选择最优的蜂窝用户进行资源共享.仿真结果表明该算法能有效的提升通信网络的吞吐量,可以为D2D用户选择最优的资源分配策略.  相似文献   

9.
针对无线功率传输技术的能量收集效率有限造成信噪比下降进而引发通信中断率增加的问题,在能量收集多跳D2D(Device to Device)无线传感网络中,提出一种基于改进K-means聚类的中继选择方法。首先,推导得到能量收集下的信噪比因子,使其作为K-means聚类特征。然后,利用最小欧氏距离原则得到距离聚类中心最近的实际节点的位置。最后,根据距离重排序得到中继节点,形成从源节点到目的节点的通信链路。仿真实验结果表明,相比最短路径算法和随机中继协作方案,所提出的改进算法链路信噪比更大,能够减小通信中断率,具有更好的中继性能。  相似文献   

10.
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。  相似文献   

11.
在D2D通信系统与蜂窝网络共存的场景下,引入中继节点可有效提高D2D链路的吞吐量和D2D用户对蜂窝用户的干扰。文中基于译码转发模式,结合跨层协作通信的思想,提出了一种基于物理层和数据链路层的跨层中继选择算法。该算法结合物理层的信道状态信息和数据链路层的队列状态信息,两个参数进行最优中继节点的选择。并最终通过仿真验证表明,基于跨层中继选择算法可提高通信系统的吞吐量,同时降低了通信系统的平均时延和数据包错误率。  相似文献   

12.
ABSTRACT

In this paper, we consider a multi-hop device-to-device (D2D) communication, which enables communication from functional area (FA), where the D2D users are placed near to base station (BS) under its coverage to non-functional area (NFA). In our proposed model, random deployment as well as certain distance-dependent deployment of D2D node is considered in NFA. In case of FA, BS is transmitting information with fixed transmit power in multi-hop D2D network. In case of NFA, a D2D node harvests energy from its preceding node, and forwards the information to the successive node. Parallel best path selection (PBPS) and immediate best path selection (IBPS) strategies are considered for FA while several cases of deployment strategies based on inter-node distance is considered for NFA to reach the final destination node. A framework has been proposed for evaluating throughput, ergodic capacity and outage probability. Energy consumption in the system has been estimated via simulation. The throughput performance, ergodic capacity and the outage probability of end-to-end link (i.e. from BS to NFA) under different system parameters are evaluated.  相似文献   

13.
This paper presents a device‐to‐device (D2D)–pairing scheme based on Voronoi diagram, which establishes D2D links by the relation of transmission powers and link distances. Using the principle of stochastic geometry and channel inversion, the coverage probability is analyzed, we observe that the co‐channel interference caused by cellular networks is stable in theory, and the influence of link distance parameter is highlighted as well. According to the second‐order moment of link distance, the new metric space of D2D terminals set is constructed, in which Voronoi diagram is degenerated into Delaunay triangles set to represent the potential D2D links. In addition, on the basis of the mini‐max length criterion of Delaunay triangle, the D2D communication range–limiting algorithm is designed. Finally, the more intuitive results compared with conventional D2D communications are displayed by simulations. Owing to restraining the D2D communication range, lower co‐channel interference can be obtained. Specially, the D2D‐pairing scheme is approximate local optimal under the D2D communication range–limiting algorithm, and it can provide more fairness than greedy algorithm.  相似文献   

14.
Recent advances in intelligent transportation systems enable a broad range of potential applications that significantly improve the vehicle and road safety and facilitate the efficient dissemination of information among the vehicles. To assist the vehicle traffic, message broadcasting is a widely adopted technique for road safety. But efficient message broadcasting is a significant issue, especially in a high network density due to the broadcast storm problem. To solve this issue, several methods are proposed to eliminate the redundant transmission of safety packets. However, they lack in restricting the broadcasting region of safety messages, and the transmissions of safety packets outside the dangerous region, and force the vehicles to unnecessary detours. This paper proposes an adaptive multimode routing protocol, network condition, and application‐based data adaptive intelligent message routing in vehicular network (NetCLEVER) that supports 2 modes of operation such as message broadcasting and intelligent routing. In message broadcasting mode, the NetCLEVER decides the dangerous region of the network by considering the changes of neighbor vehicles velocity, instead of current vehicle velocity, because a vehicle decision in velocity is interdependent with the preceding vehicles. In intelligent routing mode, the NetCLEVER exploits the cuckoo search optimization in routing by taking into account multiple routing factors such as the road topology of intersections and traffic signals and their impact on link stability, which improves the reliability of routing packets significantly. The performance evaluation illustrates that the proposed NetCLEVER improves reliable wireless communication as well as road safety in vehicular ad hoc networks.  相似文献   

15.
Vehicular ad-hoc network (VANET) is characterized as a highly dynamic wireless network due to the dynamic connectivity of the network nodes. To achieve better connectivity under such dynamic conditions, an optimal transmission strategy is required to direct the information flow between the nodes. Earlier studies on VANET’s overlook the characteristics of heterogeneity in vehicle types, traffic structure, flow for density estimation, and connectivity observation. In this paper, we have proposed a heterogeneous traffic flow based dual ring connectivity model to enhance both the message disseminations and network connectivity. In our proposed model the availability of different types of vehicles on the road, such as, cars, buses, etc., are introduced in an attempt to propose a new communication structure for moving vehicles in VANETl under cooperative transmission in heterogeneous traffic flow. The model is based on the dual-ring structure that forms the primary and secondary rings of vehicular communication. During message disseminations, Slow speed vehicles (buses) on the secondary ring provide a backup path of communication for high speed vehicles (cars) moving on the primary ring. The Slow speed vehicles act as the intermediate nodes in the aforementioned connectivity model that helps improve the network coverage and end-to-end data delivery. For the evaluation and the implementation of dual-ring model a clustering routing scheme warning energy aware cluster-head is adopted that also caters for the energy optimization. The implemented dual-ring message delivery scheme under the cluster-head based routing technique does show improved network coverage and connectivity dynamics even under the multi-hop communication system.  相似文献   

16.
In order to solve the problem of interference caused by D2D users reuse cellular resources in cellular network,an algorithm of interference control and resource allocation of D2D communication in single cell cellular system was proposed.Firstly,an interference graph was constructed according to the interference between users in the system to find the reusable channel resource for D2D users.Then,the channel resource pre-allocation and the channel switching policy were performed for D2D users in sequence according to the preset D2D user priority.The simulation results show that the proposed algorithm can significantly improve the system throughput and the access rate of D2D users so that the system can achieve better performance in the presence of small or large number of D2D users.  相似文献   

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