在AOS空间通信系统中，跨层资源优化是研究的热点和难点问题。针对时延大、误码率高的空间环境特点和满足信源用户对服务质量(QoS)的要求，本课题首先结合无线信息传输系统的理论，开展AOS空间信息系统跨层资源优化研究，建立AOS的跨层资源优化模型，在该模型基础上提出基于QoS保证的跨层资源优化方法；其次，同时根据实时AOS空间链路状态，灵活地选取调制方式、编码方式以及重传方式，研究AOS链路自适应与混合自动重传联合跨层优化的新方法，以及基于虚拟调制编码方式的链路自适应跨层优化技术；最后，对研究的结果进行仿真、测试与验证。研究结果可以解决AOS空间通信系统中传输的关键技术问题，对提高AOS空间通信系统的总体性能研究具有重要的理论意义和实际应用价值，为未来的空间信息网络建设提供坚实的理论基础和技术储备。

In AOS, research on cross-layer resource optimization is becoming a hot spot problem and difficult problem. Firstly, it joins the theory of wireless information transmission in this task, with developing research of AOS space information system cross-layer resource optimization, establishing AOS cross-layer resource optimization model, and proposing proposed QoS-based cross-layer resource optimization algorithm based on the basis of the model, aim to high bit error rate and long delay of space condition and fitting to QoS. Secondly, according to the state of AOS space link, the flexible selection of modulation, and the method of coding and retransmission, a new method is studied about the combination of link adaptation and hybrid automatic retransmission, and the optimized link adaptation scheme based on virtual modulation and coding. Finally, the results can be simulated, tested and verified. The key problems of transmission of AOS space in a communication system will be solved in this task. It has important theoretical significance and practical application value to improve the overall performance of AOS communication system, and provides the theoretical basis and solid technical reserves for the construction of space information network in future.