CCF- Unified View of Multiterminal Source Coding

在各种应用中，例如天气监测、智能建筑和制造系统，远程部署的传感器网络（每个传感器都有通信约束）的目标是进行集体推理。然而，这种传感器（信息源）网络的控制原理以及性能限制尚未得到很好的理解。因此，大多数实际系统的设计都是保守的，为未来的改进和降低成本留下了很大的空间。在此背景下，研究人员确定了网络（多终端）源编码的某些基本原理，并在香农的精神下研究了性能界限。这项研究有几个好处：(1)由于设计基准，研究投资有吸引力的经济回报；(2)对一大类网络编码问题的统一概念认识；(3)开发培训工程师设计和维护分布式系统的学术材料和课程。研究人员给出了一类广泛的多端源编码问题的渐近性能界的典型理论。特别是，它们采用统一的失真无关编码策略，只有在适当的后处理后才表现出失真。重要的是，无处不在的单字母描述概念与某种图形表示相关联；如果相应的图不存在环，则保证这种描述的存在性。因此，调查人员找到了迄今为止单一助手问题的单一字母解决方案。相反，有循环的图，例如在著名的伯格-东问题中看到的，可能不存在单字母解。因此，伯格-东界限被推测是宽松的，目前正在努力寻找一个结论性的答案。然而，在缺乏单字母描述的情况下，规范理论仍然为可计算的描述和可处理的计算算法提供了一个通用的路线图。

In a variety of applications, such as weather monitoring, smart buildings, and manufacturing systems, a network of sensors, each with a communication constraint, is remotely deployed with the goal of making collective inference. However, the governing principle, as well as the performance limit, of such sensor (information source) networks is not well understood. Consequently, most practical systems are designed conservatively, allowing significant room for future improvement and cost reduction. In this backdrop, the investigators identify certain fundamental principles underlying network (multiterminal) source coding, and study performance bounds in the spirit of Shannon. This research entails several benefits: (1) attractive economic returns on research investment due to design benchmarking; (2) unified conceptual understanding of a large class of network coding problems; (3) development of academic materials and courses for training engineers in design and maintenance of distributed systems.The investigators give a canonical theory characterizing the asymptotic performance bound for a broad class of multiterminal source coding problems. In particular, they employ a unifying distortion-independent coding strategy, which manifests distortion only upon suitable post-processing. Importantly, the ubiquitous notion of single-letter description is connected to a certain graphical representation; existence of such description is guaranteed if the corresponding graph admits no cycles. As a consequence, the investigators find a single-letter solution to the hitherto-open single-helper problem. On the contrary, graphs with cycles, seen, for example, in the famous Berger-Tung problem, likely admit no single-letter solution. Accordingly, the Berger-Tung bound is conjectured to be loose, and work towards a conclusive answer is in progress. However, in absence of a single-letter description, the canonical theory still provides a general road map towards a computable description, and tractable computational algorithms.