我国空间信息网信号传输因地面布站受限而严重依赖于空间链路，传统物理层固定的编码调制体制无法有效适应大时延高动态时变空间链路，成为提升空间网络信息传输能量效率和频谱效率的瓶颈。鉴于空间轨道飞行器拥有自主感知飞行状态信息的特点，通过飞行状态参数空间到通信信道参数空间的映射，使得大时延条件下无反馈的速率适配编码调制成为可能。本项目将开展高动态时变条件下基于飞行器自主感知的速率适配编码调制理论研究，建立动态时变空间链路的信道模型并分析其遍历容量与中断容量，设计高能量效率高频谱效率的从信息比特到传输符号的速率适配直接映射结构，建立低复杂度的近最优解映射方法。本项目对高能量效率、高频谱效率的空间链路物理层编码调制统一映射理论的研究，将为我国空间信息网发展提供具有创新性的科学理论与方法支持以实现高起点、跨越式的发展。

The space-based information network of our country relies heavily on space link due to the limitation on overseas ground stations. The conventional fixed-rate coded modulation schemes cannot adapt to time-varying space link with long delay and high dynamic, which becomes a bottleneck for the improvement of space-based information network’s energy efficiency and spectral efficiency. In view of the facts that spacecrafts have the ability to obtain flight status without the help of external systems, it is possible to design no-feedback rate-adaptive coded modulation through projection from parameter space of instant flight status to parameter space of communication channel. The program will develop the rate-adaptive coded modulation theory based on self-perception of spacecrafts under high dynamic time-varying environments. In this program, the high dynamic time-varying space link channel will be established, the ergodic capacity and outage capacity of this channel will be analyzed, adjustable mapping methods of information bits directly to transmitting signal symbols for high energy efficiency and high spectral efficiency will be designed, low-complexity near-optimal demapping methods will be proposed. The research of high energy efficiency and high spectral efficiency coded modulation theory for physical layer of space link in this program will shed light on the theory and methodological guidance for enhancing reliability for our country’s space-based information networks, and realize high step and leap-forward development.