基于OFDM系统的高移动性快变干扰信道容量界的研究

Providing broadband wireless transmission service on high speed vehicles is one of the requirement that 5G need meet. OFDM has been regarded as a promising candidate for high-mobility wireless communication. Capacity regions of the OFDM systems in high-mobility environment over rapidly time-varying interference channels serve as an important tool for guiding the construction of the OFDM system and the efficient collocation of resource. In this project we involve the following three aspects. 1) Channel models: we focus on the relationship between velocity and channel gains matrix as well as interference coefficients in order to build the model of the OFDM system in the high-mobility environment over rapidly time-varying interference channels. 2) Accessible capacity in high-mobility environment: we focus on the maximum transmission rate at which high-mobility users can communicate reliably without affecting the error performance requirement by the original users. 3)Capacity region: we focus on the computable capacity bounds of the OFDM systems in high-mobility environment over rapidly time-varying interference channels. We treat rapidly time-varying interference channels in a new insight with primary and secondary users. Based on computable mutual information, we will hopefully achieve some valuable results of the capacity bounds both on the theoretics and the practice, which will support the design and implementation of the next-generation wireless communication system in high-mobility environment.

高速列车宽带无线传输是下一代无线通信系统5G将要解决的标准场景之一。正交频分复用（OFDM）则被视为解决高移动场景下宽带无线传输的有力候选。研究基于OFDM系统的高移动性快变干扰信道的容量区域可以用来指导此类无线通信网络的设计与建设，提高信息传输效能。本项目主要研究内容涉及三个方面。1）信道模型：分析速度与信道特征矩阵和干扰系数的关系，建立基于OFDM系统的高移动性快变干扰信道的数学模型；2）移动接入容量：研究高移动环境中，在不影响原小区用户错误性能的限制下高速列车用户的最大可靠传输速率；3）信道容量：研究基于OFDM系统的高移动快变干扰信道的容量区域及可计算容量界。本项目从新的主次用户角度切入对快变干扰信道容量的研究，基于有意义的互信息值估计信道不匹配时的容量界。项目的研究成果不仅可以丰富传统的香农信息理论，也必将为5G网络中高移动环境下无线传输系统的设计和实践提供理论依据和技术支持。

高速列车宽带无线传输是下一代无线通信系统5G将要解决的标准场景之一。正交频分复用（OFDM）则被视为解决高移动场景下宽带无线传输的有力候选。研究基于OFDM系统的高移动性快变干扰信道的容量区域可以用来指导此类无线通信网络的设计与建设，提高信息传输效能。本项目从香农信息论的角度出发，对基于OFDM系统的快变干扰信道展开研究。首先，通过运用信息谱方法，给出了一般干扰信道容量区域的理论公式。同时，结合BCJR算法，对特殊情况下的信道容量给出了可计算的方案；提供了一种新的视角来理解干扰信道的容量区域。其次，建立了高移动环境下快变干扰信道的模型。针对所提出的模型，仿真实验模拟了速度和信道状态信息对系统性能的影响。第三，针对快变OFDM系统与实际编译码方案结合后的系统，设计了一个易于计算且鲁棒性较高的均衡器。这些研究不仅丰富了香农信息论的内容，也为面向5G的OFDM系统的设计与实现提供了理论指导和技术支持。