基于LTE协助的车联网多媒体QoS智能调度算法研究

With the world-wide deployment of LTE networks and its advanced technologies (e.g., eMBMS and D2D), LTE-assisted vehicular infrastructure has become a promising solution for broadband multimedia transmission over vehicular networks with the golden opportunity to overcome the drawbacks of the current WAVE/DSRC-based vehicular infrastructure. In this project, we aim at developing new scheduling mechanisms in order to provide QoS-aware multimedia services in LTE-assisted vehicular networks. We first summarize the multimedia transmission into four categories based on the user’s service requests and the characteristics of vehicular-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) communication. Then we explore the major QoS metrics of multimedia delivery in each mode, and propose QoS-driven smart scheduling algorithms for multimedia transmission over LTE-assisted vehicular networks. In particular, the proposed scheduling algorithms can provide three-fold benefits: 1) QoS assured multimedia service with thorough consideration of multimedia delay constraints; 2) Seamless handover of multimedia services when a vehicle crosses the border of one LTE cell to another; 3) Proactive interference avoidance between V2I and V2V communications. The proposed project can provide a valuable guidance to the theory exploration, algorithm derivation and evaluation of QoS-oriented multimedia transmission over vehicular networks. In addition, the proposed framework and scheduling algorithms can be considered as references to the research and development, real-world implementation, and standardization of future smart vehicular networks.

本项目研究使用LTE协助实现车联网中多媒体通信，通过对LTE、eMBMS和D2D等技术在车联网中的合理扩展，有效克服当前主流车联网协议在多媒体传输领域存在的缺陷。首先，通过细化车联网中多媒体服务种类并分析车对交通基础设施（V2I）和车对车（V2V）通信的特点，将车联网中多媒体传输归纳为V2I单播、V2I组播、V2V单播和V2V广播四种模式。接着，通过对各种传输模式下QoS主要影响因素的研究与分析，提出基于QoS驱动的智能调度算法，并采用系统级LTE模拟器进行仿真验证。本课题提出的调度算法具有三点优势：1)在延迟限制条件下实现小区内多媒体的可靠传输；2)通过对LTE网络硬切换和车联网频繁跨区切换的特殊处理，实现车辆跨区时的无缝切换；3)通过干扰避让资源调度算法实现V2I和V2V通信的频带资源共享。本课题的研究为车联网多媒体QoS传输的研发、实用化和标准制定提供理论依据、算法实现和实验验证。

本项目通过扩展LTE标准中的eMBMS和D2D等技术，实现LTE协助下的车联网多媒体通信。重点研究三方面内容：（1）通过细化车联网中多媒体服务种类和分析车联网通信的特点，进一步探索车联网多媒体传输的QoE和QoS主要影响因素，并创造性的提出基于云计算的手机视频传输结构，使用户在观看多媒体视频的同时降低手机能耗；（2）通过研究802.11p和LTE协议在通信延迟和丢包率等QoS指标的不同表现，提出车联网V2I通信在LTE-802.11p混合模式下的无缝切换协议；通过智能干扰避让技术实现V2I和V2V通信的频带资源共享；（3）从物理层出发，通过预编码和毫米波多天线选择技术实现车联网无线通信的高性能传输。同时，随着5G网络的发展与初步商用，探索将二维音视频多媒体服务扩展为三维音视触觉相融合的多媒体服务，成功申请国家自然科学基金国际（地区）合作研究项目1项（直接经费116万）。本项目的研究成果发表SCI期刊论文10篇，EI国际会议论文10篇，申请国家发明专利2项，完成硕士毕业论文2本。本课题的研究为车联网多媒体QoS传输的研发、实用化和标准制定提供理论和实验依据。