语用信息的数学理论OA
A mathematical theory of pragmatic information
本文提出语用信息的数学理论,将通信、控制与决策纳入同一个框架.核心是"同效映射"(isoteleia mapping),揭示了语用信息的本质——同效性:不同语义路径若导向相同最优动作,则在语用上等价.该映射诱导语法、语义、语用三层信息层级,每层抽象都丢弃与任务无关的细节.在此基础上,本文建立语用层面的信息论度量,包括语用熵、上/下语用互信息、语用信道容量与语用率失真函数,并证明3个编码定理——语用无损信源编码、语用信道编码与语用率失真编码.与经典和语义信息论相比,该框架的关键在于以"信息对行动的有效性"为核心度量,而非符号或语义保真度. 在信息度量之外,本文引入语用信息价值(VoI)与语用信息成本(CoI),分别作为率失真函数与信道容量的决策论对偶.VoI 衡量信息带来的期望效用增益,CoI 衡量给定语用速率下所需的最小资源消耗.二者构成Legendre-Fenchel 型对偶,并通过拉格朗日框架实现跨层优化.由此得到语用效率上界,即行为容量,刻画资源受限智能系统在给定资源价格下的最大净效用.对于连续消息,本文给出高斯信源与高斯信道的闭式表达,包括语用容量、语用率失真及相应 VoI 与 CoI;对于双边与单边抽象,分别给出感知路径与表达路径的对偶关系.在动态场景中,本文将框架扩展到部分可观测马尔可夫决策过程,并推导信念状态下的贝尔曼方程. 语用信息论框架为任务导向通信、网络化控制、自主系统与具身智能提供统一数学语言,将关注点从符号保真度转向信息对行动的有效性.具体而言,语用熵刻画决策不确定性,语用容量刻画可靠传递最优动作的最大速率,语用率失真刻画给定任务失真下所需的最小速率,而VoI与CoI则分别从收益与代价两侧给出资源分配的决策论依据.这些度量与经典和语义信息论保持层次兼容:当同效映射退化为恒等映射时,语用信息论退化为语义信息论;当同义映射也退化为恒等映射时,进一步退化为经典信息论.因此,该框架在保持向后兼容的同时,将信息论适用范围从符号传输扩展到目标导向的行为决策. 本文的基础贡献在于,将语用信息从哲学概念推进为可定义、可计算、可证明的数学对象,并在信息论中首次建立语法-语义-语用三层统一的严格层次.它通过同效映射与同义映射的复合,把信息论极限、决策论目标与物理资源约束连接起来,为任务导向通信、语义通信、6G、大模型与AI Agent、具身智能、自动驾驶等通信与人工智能融合方向,提供了以任务效用为中心的设计语言,推动信息传输从"比特保真"走向"传递对行动真正有效的信息",具有重要的理论指导意义.
We propose a mathematical theory of pragmatic information that unifies communication,control,and decision-making within a coherent framework.At its core is the isoteleia mapping,which formalizes equifinality:distinct semantic paths that lead to the same optimal action are regarded as pragmatically equivalent.This mapping induces a three-tier hi-erarchy of syntactic,semantic,and pragmatic information,in which each successive abstraction discards distinctions that are irrelevant to the task.Building on this hierarchy,we develop a set of information-theoretic measures at the pragmatic level,including pragmatic entropy,up/down pragmatic mutual information,channel capacity,and rate-distortion.In ad-dition,we prove three coding theorems—lossless source coding,channel coding,and rate-distortion—which generalize Shannon's classical results.We then introduce pragmatic value of information(VoI)and pragmatic cost of information(CoI)as decision-theoretic duals to rate-distortion and capacity,respectively,and formulate a Lagrangian dual framework for cross-layer optimization.The resulting pragmatic efficiency bound εp(λ)=supR[Φp(R)-λCoIp(R)]characterizes the maximum net utility attainable by a resource-constrained intelligent system under a given resource price,thereby providing a limit on purposeful behavior—abehavioral capacity.This limit can be viewed as a goal-directed analogue of Shannon's symbol-level capacity under the stated utility and resource assumptions.Extensions to continuous messages yield closed-form expressions for Gaussian channels and sources,while dynamic settings are addressed through a Bellman equation for sequential decision-making.Finally,this framework provides a foundation for task-oriented communication,networked control,autonomous systems,and embodied AI,shifting the focus from symbol fidelity to the effectiveness of information in guiding actions,and offering a mathematical language for the design of next-generation intelligent systems.
牛凯;张平
北京邮电大学泛网无线通信教育部重点实验室,北京 100876北京邮电大学网络与交换技术全国重点实验室,北京 100876
信息技术与安全科学
语用信息论同效映射具象映射语用熵语用互信息语用信道容量语用率失真信息价值信息成本语用拉格朗日量行为容量
pragmatic information theoryisoteleia mappingreification mappingpragmatic entropypragmatic mutual informationpragmatic channel capacitypragmatic rate-distortionvalue of informationcost of informationpragmatic lagrangianbehavioral capacity
《通信学报》 2026 (9)
6-90,85
国家重点研发计划项目(No.2025YFF0514400,No.2025YFF0514404)教育部基础学科和交叉学科突破计划项目(No.JYB2025XDXM119)国家自然科学基金重大项目(No.62293481,No.62471054) The National Key Research and Development Program of China(No.2025YFF0514400,No.2025YFF0514404),The Fundamental and Interdisciplinary Disciplines Breakthrough Plan of the Ministry of Education of China(No.JYB2025XDXM119),The National Natural Science Foundation of China(No.62293481,No.62471054)
评论