CIF: Small: Fundamental limits of interactive communications

这项拟议的研究旨在了解交互如何影响通信系统的基本性能。“交互”是指当前的决策，例如输入到通道的什么，何时可以基于过去的决策而改变，例如通过反馈或访问通道输出。为了评估交互的影响，该项目使用了独立于技术的信息论形式主义，它量化了数据压缩和传输的基本限制。这为交互通信系统的真实世界性能提供了上界和基准，这将比目前考虑理想化反馈概念的上界更现实。这有望改进在许多现有和未来的通信范例中相关的噪声反馈和双向设置中的通信系统的设计。将使用三个信息论度量来考察在具有噪声反馈的单向信道和双向信道中交互的作用：1)略粗的容量观点；2)更精细的误差指数角；以及最后3)更精细的二阶编码/有限块长度上下文。带有噪声反馈的单向通道突出了调整电流输入以适应过去噪声通道输出的潜在效用或徒劳之处，扩展了对当前技术状态的理解，目前大多数情况下认为无噪声/完美输出反馈。双向通道，其中两个用户希望通过公共通道交换消息并以交互方式这样做，通过不仅捕捉交互/反馈的影响，而且捕捉使用公共通道在一个方向上发送数据与在另一个方向上的反馈之间的紧张关系，从而使这种理解更进一步。拟议研究的结果将提供对两个更现实和相对未被探索的互动环境中的互动的全面了解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The proposed research aims to understand how interaction affects the fundamental performance of communication systems. "Interaction" denotes when current decisions such as what to input to the channel may be altered based on past decisions, for example through feedback or access to channel outputs. To assess the impact of interaction, this project uses the technology-independent formalism of information theory, which quantifies the fundamental limits of data compression and transmission. This provides upper bounds and benchmarks for real-world performance of interactive communication systems, which will be more realistic than current bounds which consider idealized notions of feedback. This is expected to refine the design of communication systems in the noisy feedback and two-way settings of relevance in many existing and future communication paradigms.The role of interaction in one-way channels with noisy feedback and two-way channels will be looked at using three information theoretic metrics: 1) the somewhat crude capacity viewpoint; 2) a more refined error exponents angle; and finally 3) the even more refined second order coding / finite-blocklength context. One-way channels with noisy feedback highlight the potential utility or futility of adapting current inputs to past noisy channel outputs, extending the understanding from the current state of the art which for the most part considers noiseless / perfect output feedback. Two-way channels where two users wish to exchange messages over a common channel and do so interactively take this understanding one step further by capturing not only the impact of interaction / feedback, but also the tension between using a common channel to send data in one direction versus feedback in the other. The outcomes of the proposed research will provide a comprehensive understanding of interaction in two more realistic and relatively unexplored interactive settings.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.