CIF: Small: Efficient Satellite Relaying

CIF：小型：高效卫星中继

• 批准号: 1116997
• 负责人: Stephen Wilson
• 金额: $ 33.3万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1116997&HistoricalAwards=false
• 关键词: CIF; Small; Efficient; Satellite; Relaying

Data networking via satellite relays remains an important means of linking globally-distributed network terminals for both commercial and governmental applications, especially in remote regions. Modern applications demand both spectrum and power efficiency in the network. The archetype network model in such networks is one with two terminals wishing to exchange data via a single satellite transponder. Relative to traditional time-sharing or frequency-sharing for the bidirectional communication paths, information-theory reveals that spectrum efficiency gains of up to 100% can be obtained for a given set of link power resources. These gains are possible when non-orthogonal transmission methods are adopted, and the decoders exploit side-knowledge on previously-transmitted information. The project codifies various protocols appropriate to this two-terminal data exchange model, including amplify-forward, as well as protocols that involve satellite decoding/re-encoding. The possible gains depend on link resources as well as the desired bidirectional rate targets. Existing research for this problem presumes perfect synchronization and side-information at both terminals, but practical issues of large round-trip delay, carrier phase/frequency synchronization, and symbol synchronization are important obstacles to achieving the promise of information theory. So the investigators develop realistic synchronization protocol designs that approach the ideal information-theoretic limits. In addition, the project studies a new decode-and-forward relaying protocol based on nested LDPC coding on downlinks that is flexible in terms of rate-asymmetry.

通过卫星中继的数据网络仍然是连接全球分布式网络终端的重要手段，适用于商业和政府应用，特别是在偏远地区。 现代应用要求网络中的频谱和功率效率。 此类网络中的原型网络模型是具有两个希望通过单个卫星转发器交换数据的终端的网络模型。相对于双向通信路径的传统分时或频率共享，信息论表明对于给定的一组链路功率资源可以获得高达 100% 的频谱效率增益。当采用非正交传输方法并且解码器利用先前传输的信息的辅助知识时，这些增益是可能的。 该项目编纂了适合这种两端数据交换模型的各种协议，包括放大转发以及涉及卫星解码/重新编码的协议。 可能的增益取决于链路资源以及所需的双向速率目标。 针对这一问题的现有研究假设两个终端都具有完美的同步和辅助信息，但大往返延迟、载波相位/频率同步和符号同步的实际问题是实现信息论承诺的重要障碍。因此，研究人员开发了接近理想信息论极限的现实同步协议设计。此外，该项目还研究了一种基于下行链路嵌套 LDPC 编码的新解码转发中继协议，该协议在速率不对称方面非常灵活。