面向2N倍频谱效率的大尺度同时同频全双工MIMO关键技术研究

The wireless co-time co-frequency full-duplex communication has been treated as an effective way to significantly increase the spectrum efficiency of 5G wireless networks. Although single antenna full-duplex communication can double spectrum efficiency as compared with the single antenna half-duplex communication, the full-duplex multiple-input-multiple-output (MIMO), which integrates the full-duplex and multiplexing MIMO, can achieve the largest spectrum efficiency of full-duplex communications. However, there often exists the tradeoff between full-duplex mode and multiplexing MIMO...On the other hand, the existing schemes of full-duplex communications are basically designed for small-scale scenarios, where the communication distance is a scale from several meters to hundred of meters. However, it is more meaningful to design full-duplex schemes for large-scale scenario, where the communication distance is more than one thousand meters. Since the self-interference/mutual-interference under large-scale/MIMO scenarios is much more serious than that of the small-scale scenarios, it is needed the more advanced interference cancellation schemes for full-duplex communications under large scale scenarios...To solve the above-mentioned problem, this project places the research emphasis on designing self-interference/mutual-interference cancellation schemes to achieve the 2N-fold spectrum effiency for large-scale full-duplex communications. We also build the mathematical model for residual self-interference and mutual-interference. Based on the mathematical model, we develop several key physical layer techniques for wireless full-duplex MIMO communications. The research can not only solve the problem of achieving the 2N-fold spectrum.efficiency for wireless full-duplex MIMO communications, but also afford the powerful support for the 5G wireless networks.

同时同频全双工通信被认为是5G网络提高频谱效率的有效途径。尽管单天线全双工可达2倍于单天线半双工的频谱效率，将全双工与多天线复用模式相结合，从而获取2倍于多天线半双工的频谱效率，才是全双工通信最大可达的频谱效率。然而，全双工与多天线复用对多天线资源的使用往往存在冲突。..另一方面，现有的全双工通信基本针对通信距离为米至百米数量级的小尺度情形而设计，但在通信距离为公里数量级的大尺度情形下实现全双工才更具实际意义。大尺度/MIMO全双工通信情形下，自／互干扰更加凸显，这给全双工通信提出了更高的干扰消除要求。..针对上述问题，本课题拟开展面向2N（N为节点发射天线个数）倍频谱效率的大尺度全双工多天线自/互干扰消除方法研究， 并建立相应的残余自/互干扰数学模型，在此基础上，突破物理层若干关键技术。本研究成果不仅可解决大尺度全双工最大频谱效率获取问题，而且可为提高5G网络频谱效率提供必要的支撑。

在带宽资源紧缺的当下，为了使未来移动通信网络的容量相对现有系统有质的飞跃，需要从提高频谱效率的角度着手，在根本上提高通信系统的传输能力。同时同频全双工通信被认为是未来无线通信网络提高频谱效率的有效途径。尽管单天线全双工可达2倍于单天线半双工的频谱效率，将全双工与多天线复用模式相结合，从而获取2N（N为节点发射天线个数）倍的频谱效率，才是全双工通信最大可达的频谱效率。然而，全双工与多天线复用对多天线资源的使用往往存在冲突。另一方面，现有的全双工通信基本针对通信距离为米至百米数量级的小尺度情形而设计，但在通信距离为公里数量级的大尺度情形下实现全双工才更具实际意义。大尺度/MIMO全双工通信情形下，自／互干扰更加凸显，这给全双工通信提出了更高的干扰消除要求。..针对上述问题，本项目设计了单天线单阵元自干扰抵消结构、单天线多阵元互干扰对消结构、以及多天线多阵元互干扰抑制结构，并建立了相应的残余自/互干扰数学模型。基于以上三种结构，提出了三维精确控制跨域自干扰抵消方法、基于分形阵元的自干扰抵消方法、基于波束成形的互干扰抑制方法，实现了在不消耗天线资源的情况下对本地极大自干扰的抑制，为大尺度同时同频全双工MIMO通信提供了技术支撑。此外，突破了大尺度全双工MIMO物理层若干关键技术，重点分析了大尺度全双工MIMO的自干扰信道、互干扰信道、有用信号信道的混叠影响机制，设计了联合信道估计方法；利用残余自/互干扰协助进行编码设计，提出了全双工空时编码方案，实现了异步全协作分集；针对不同数量级的残余自/互干扰，设计了自适应残余自/互干扰的最优功率分配方法，从而最大化大尺度全双工MIMO的容量；针对大尺度全双工MIMO通信的时延问题，构建了时延服务质量保障机制，提出了大尺度全双工MIMO有效容量最大化方法。本研究成果不仅可解决大尺度全双工最大频谱效率获取问题，而且可为提高未来网络频谱效率提供必要的支撑。