下一代移动通信系统中基于干扰消除的强度空间复用技术

In order to address the rapid-growing demands on wireless data communications in the future, the next-generation wireless communication systems should have much higher spectrum efficiency due to the limited radio spectrum. Instead of installing more antennas, which may suffer from the finite size of base stations, we try to exploit the transmission potentials in signal scale. Specifically, motivated by the research on the areas of interference alignment and physical-layer network coding, a novel multiplexing technology along signal-scale space is proposed for MIMO and heterogeneous networks in this project, where wireless signals of different power levels can be delivered and differentiated in the same vector dimension, improving the spectrum efficiency...This project is expected to provide a solution of signal-scale multiplexing technology for the next-generation cellular systems, with innovative designs, solid theoretical studies as well as convincing performance evaluations. To achieve this goal, we shall first study the practical transceiver design of multi-antenna links with signal-scale multiplexing schemes, and then address the robustness issue by taking the imperfect channel state information at the transmitter into account in the transceiver design. Based on the link-level transceiver design, we shall continue to exploit the multi-user diversity gain of the proposed signal-scale multiplexing schemes by optimal scheduling algorithm. Moreover, system-level performance gain of the proposed technology will be evaluated via both theoretical analysis and simulations. Finally, the proposed technology will be demonstrated in a testbed and performance data will be collected.

为了在有限的频谱带宽中满足急速增长的无线通信需求，下一代移动通信系统迫切需要从各个方面提升频谱效率。以干扰对齐、物理层网络编码等领域的研究为基础，我们在本项目中提出了在异构、多天线的移动通信系统中利用功率差异在信号的强度空间发掘传输潜力的复用技术，即根据下一代移动通信系统的特点，在同一个向量维度上同时传输不同功率的无线信号，从而提高频谱效率。. 为了全面掌握强度空间复用技术，我们将首先研究在多天线、信道信息存在测量误差的传输链路中如何在强度空间进行多路信号的叠加和检测，包括如何优化叠加方式，如何消除干扰等；在系统层面，我们将研究基于强度空间复用的多用户调度算法，分析用户多样性对复用技术的影响，分析复用技术给移动通信系统带来的整体增益；在测试方面，我们将搭建实验平台进行性能实测。本性项目将输出兼具理论性和实用性的强度空间复用技术，为下一代移动通信系统提供有竞争力的候选技术。

本项目主要关注未来蜂窝网络中在信号的强度空间进行干扰消除的关键技术，涉及的网络形态包括：大规模多天线系统，具备云计算能力的无线异构接入网络和采用非正交多址复用的密集部署蜂窝。在大规模多天线系统的上行传输中，我们提出了利用上行数据以及无线信道小尺度衰弱的时间相关性进行上行干扰抑制的若干传输技术；在下行传输中，我们提出了利用跨帧调度进行干扰抑制的若干传输技术；此外，我们还基于随机集合等数学工具建立了一个适用于大规模多天线技术系统级性能分析的理论工具。该理论工具可以进一步扩展到大规模多天线系统与设备间直接通信共存的场景中，进行传输性能预测和无线资源调度。在无线异构网络中，我们主要针对小基站和宏基站间具备有限带宽的回程链路的场景，利用随机过程和随机优化等数学工具设计了上行传输的干扰抑制和无线资源调度算法。而针对密集部署蜂窝，我们主要关注在信号的强度空间进行传输复用和干扰消除的关键技术，进行收发机的设计，并且通过硬件测试平台进行性能验证。本项目的预期的全部研究内容均已完成，输出的研究成果达到或者超过预期目标。