基于空间调制的多天线双向中继技术研究

The multiple-antenna two-way relaying has attracted much attention in the current research field of physical-level techniques of wireless communications. However, the conventional multiple-antenna techniques are not very efficient when the number of relay nodes (or relay antennas) varies arbitrarily and/or the power supply is scarce. Spatial Modulation is a recent concept of multiple-antenna multiplexing technique. It has the advantages of low-complexity transceiver, high energy efficiency and adaptability for arbitrary numbers of transmit and receive antennas, thus can facilitate the design of the multiple-antenna two-way relaying transmission.. This project focuses on the theory and techniques of spatial modulation aided multiple-antenna two-way relaying. First, the spatial modulation aided transmission in the scenario of single relay equipped with multiple antennas is researched. Concretely, this research includes the efficient two-user signal detection algorithm and the optimization of network coding mapping at relay node, the coded modulation scheme and the iterative detection/decoding algorithm at source nodes, and the joint antenna and sub-carrier index modulation for frequency selective fading channels at all the nodes. Second, the spatial modulation aided transmission in the scenario of distributed relays equipped with single antenna is researched. Specifically, this research includes the low-power-consumption signal detection at relay nodes, and the optimization of signal constellations and the pre-coding aided spatial modulation design for the imperfect channel condition at source nodes. . Through the research on this project, it is expected to develop both theory and technique of the spatial modulation aided multiple-antenna two-way relaying. The research results are of practical importance in theory and applications such as the future mobile communication system.

多天线双向中继技术是当前无线通信物理层传输的研究热点之一。然而，传统多天线技术并不特别适合中继处节点数或天线数可任意变化和功率供给较少的场景。空间调制是近年来提出的新型多天线技术，具有实现简单、能量效率高和适用于任意收发天线数目等优势，适合多天线双向中继传输。. 本项目将研究基于空间调制的多天线双向中继传输理论和方法。首先，研究配置多根天线的单中继场景的传输方案，包括中继节点高效两用户信号检测和网络编码映射优化、源节点编码调制结构设计和联合检测译码算法、频选信道上各节点的联合天线子载波指数调制；其次，研究配置单根天线的分布式中继场景的传输方案，包括中继节点低功耗信号检测、源节点信号星座优化和非理想条件下预编码空间调制设计。 . 本项目的研究将进一步发展和完善多天线双向中继系统中基于空间调制的传输理论和技术，有望用于未来移动通信系统，具有重要的理论及应用价值。

索引调制由于其信号稀疏性，具有发送端高能效、接收端适合采用高效稀疏信号恢复算法等优势。本项目研究空间域上的空间调制（SM）和频率域上的正交频分复用-索引调制（OFDM-IM）这两种索引调制技术。在基于SM的多天线中继方面，首先研究了基于混合SM的中继技术，提出了基于信号星座旋转和简单异或网络编码的两时隙中继方案和中继节点上的高效两级检测算法；其次研究了SM辅助的协作非正交多址，提出了一种有效的SM实现方案并理论分析了有限字符集约束下的其可达信息速率。在采用低密度奇偶校验（LDPC）码的SM编码系统方面，首先结合Gallager映射提出了一种适合任意发送天线数目的多元LDPC-SM结构；其次提出了LDPC编码正交SM高维信号星座设计方法以获得额外的成形增益。在OFDM-IM信号设计方面，首先提出利用空闲子载波发送小尺度扰动信号以降低峰均比以及在空闲子载波上发送旋转信号以获得发送分集增益的方法；其次提出了广义联合空频索引调制和基于克罗内克积的联合空频索引调制两种方案，并针对快变信道设计了最大化容量下界的线性预编码传输方案。在OFDM-IM接收机设计方面，首先研究了快变信道上的联合信道和信号检测，提出了基于半正定松弛和近似消息传递的两种信号检测算法，以及基于基扩展模型的迭代信道估计和信号检测；其次研究了大规模天线OFDM-IM的多用户检测，针对基站采用有限分辨率ADC的情况提出了基于广义Turbo原理的检测方法；此外，分别针对接收端已知和未知信道状态信息的情况，研究了基于似然概率的OFDM-IM自动调制识别技术。在基于索引调制的多址技术方面，研究了同时激活多个导频序列的免调度非正交多址非相干传输结构及其接收机实现，进一步将其推广到同时激活导频序列和信道子块的情况，以及混合多址接入场景。基于以上研究成果，本项目发展了基于索引调制的无线通信物理层调制和多址技术，为未来B5G/6G无线通信提供了有力的技术支撑。