高效协作空间调制方案的研究与优化设计

Spatial modulation (SM) as a novel multiple-input multiple-output (MIMO) technology overcomes the inherent inter-channel interference (ICI) and inter-antenna synchronization (IAS) of MIMO system and improves the system performance and transmission rate with relatively low complexity. Essentially, SM extends the traditional 2 dimensional signal modulation to 3 dimensional SM. Typical SM technology commonly activates one transmit antenna. Hence, it can eliminate the ICI and IAS. However, the available diversity gain will be affected. Moreover, SM system unavoidably encounters the channel fading and shadow effect which degrade the communication performance. Cooperative communication technology can share the antennas of the single-antenna systems and realize virtual multiple-antenna system, which achieves the cooperative diversity gain and resist the channel fading effectively. In this project, we will make intensive study on the cooperative SM technology. First, we will design more flexible high efficient SM schemes to improve the system performance and transmission efficiency, and decrease the complexity simultaneously. Then, we will merge the cooperative technology with SM organically, further extend the modulation dimension to signals, antennas, cooperative relays and their combination, and take full advantages of the system diversity gains to achieve better performance. Meanwhile, we will design the optimized cooperative SM system based on different performance goals. This project will provide important theoretical and technical support for the research and application of SM system in 5G wireless communications.

空间调制（SM）技术作为一种新的多输入多输出（MIMO）技术，从实现上克服了MIMO系统固有的信道间干扰（ICI）、天线间同步（IAS）等问题，并以较低复杂度改善系统性能和传输速率，其实质是将传统二维信号调制扩展为三维空间调制。典型SM技术仅激活单根发射天线工作，由此消除ICI与IAS，但也使其所获得分集增益受限。此外，SM系统还会受到信道衰落及阴影效应影响，使通信质量下降。协作通信技术可通过共享若干单天线系统天线协作构成虚拟多天线系统，来获得协作分集增益，抵抗信道衰落。本项目拟对协作空间调制技术进行深入研究，首先设计更加灵活高效的SM方案，进一步提高系统性能与传输效率，降低复杂度；继而将协作技术与高效SM技术有机融合，将调制维度扩展到信号、天线、协作中继及其结合，充分利用系统分集增益提高可靠性，并在不同系统性能目标下实现优化设计，为5G无线通信中SM系统的研究应用提供重要理论和技术支持。

本项目主要研究目标即对无线通信中的空间调制（SM）技术进行深入研究，进一步提高SM系统的传输性能和效率，降低系统复杂度。我们研究和设计了更加高效灵活的SM方案，继而将协作中继技术与高效SM技术进行有机融合，充分发挥两者优势，在不同系统性能要求下对系统进行优化设计。首先从高效SM系统设计入手，设计了基于余弦相似度的SM映射方案；基于空间信号分集技术提出了高效的正交空间调制（QSM）方案；通过引入天线分组，完成了基于天线分组和多天线状态的广义空间调制（GSM）系统方案；设计了基于相位旋转的高效SM预编码方案；同时将SM相关研究扩展到可见光通信领域，取得了较好成果。上述相关研究有效提升了SM系统传输可靠性和效率。随后，将SM技术与协作中继技术相结合，设计了基于索引调制的协作SM系统方案；研究了多用户多中继的协作SM系统中的天线选择及中继选择问题；同时设计了多中继的QSM系统方案和鲁棒性资源分配策略，实现了协作SM系统的性能提升。此外，在上述研究基础上，进一步基于凸优化算法等，对设计的高效协作SM方案进行了优化，主要即对比特-天线/中继/符号映射进行了联合优化，并对相关资源分配方案进行了优化。上述研究提高了SM系统及协作SM系统的可靠性和有效性，这为5G及B5G无线通信中SM系统的研究应用提供了重要理论基础和技术支持。