Fundamentals of cooperation in modern communication networks

用户合作对于任何通信网络的正常运行都是必不可少的。例如，未来的物联网等网络将是去中心化和自组织的，允许大量移动终端不断加入和离开。其中许多终端将是小规模设备，其资源(电池、天线等)都太有限了，不能自己保持沟通。这类设备依赖于其附近的其他设备来帮助将其信号传送到目的地。因此，协作网络为实现交互提供了必要的基础设施和智能。该项目旨在为协作通信的三个主要领域做出贡献：(1)网络信息理论；(2)通过物理层安全(PLS)实现安全协作；(3)协作和安全代码。我们在信息论方面的工作将集中在基本理解上，包括压缩和打包策略、交互通信、反馈和多用户二元性。我们在安全方面的工作的动机是，由于对数据共享的要求，合作本身就与隐私和安全相冲突。我们通过物理层安全将协作和安全结合在一起，其中的关键思想是利用通信信道的噪声和变化作为随机性的来源。信息论通常使用随机编码论点来获得洞察力。我们还对设计实用的合作与安全守则感兴趣。我们将研究网络编码通过向量线性和准线性编码的可靠性，以及对于网络节点协作从磁盘故障中恢复的分布式存储系统。在这里，位置、可用性和私有信息检索的概念起着核心作用。最后，我们将研究随机性，以实现保密和隐形。隐形编码基于可分解性和分布匹配，其应用于编码调制的整形、隐写和偏最小二乘法。我们将发展分布匹配理论，为中短块长度设计好的码、编码器和解码器。

User cooperation is essential for the proper function of any communications network. For example, future networks such as the Internet of Things will be decentralized and ad-hoc, allowing a multitude of mobile terminals to continuously join and leave. Many of these terminals will be small-scale devices whose resources (battery, antennas, etc.) are too limited to maintain communication on their own. Such devices depend on other devices in their proximity to help carry their signal to its destination. A cooperative network thus provides the necessary infrastructure and intelligence for interactions to materialize.This project aims to contribute to three major areas of cooperative communications: (1) network information theory; (2) secure cooperation via physical layer security (PLS); and (3) codes for cooperation and security. Our work on information theory will focus on fundamental understanding, including compression and binning strategies, interactive communication, feedback, and multiuser duality. Our work on security is motivated by the observation that cooperation inherently conflicts with privacy and security due to the requirement for data sharing. We combine cooperation and security via physical layer security (PLS) where the key idea is to exploitthe noise and variations of the communications channel as sources of randomness. Information theory usually uses random coding arguments to gain insight. We are also interested in designing practical codes for cooperation and security. We will study network coding for reliability via vector-linear and quasi-linear codes, and for distributed storage systems where network nodes cooperate to recover from disk failures. Here the concepts of locality, availability, and private information retrieval play central roles. Finally, wewill study randomness to enable secrecy and stealth. Stealth coding is based on resolvability and distribution matching that has applications to shaping for coded modulation, steganography, and PLS. We will develop the theory of distribution matching, and design good codes, encoders, and decoders for short and moderate block lengths.