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，诸如物联网的未来网络将是分散的和自组织的，允许大量移动的终端连续地加入和离开。这些终端中的许多将是小型设备，其资源（电池、天线等）它们自身的能力太有限，无法保持交流。这些设备依赖于附近的其他设备来帮助将其信号传送到目的地。因此，协作网络提供了实现交互所必需的基础设施和智能。本项目旨在对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。我们在信息理论方面的工作将集中在基本的理解上，包括压缩和分箱策略，交互式通信，反馈和多用户二元性。我们在安全方面的工作是出于这样一种观察，即由于数据共享的要求，合作本质上与隐私和安全相冲突。我们通过物理层安全（PLS）将联合收割机合作和安全结合起来，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参数来获得洞察力。我们也有兴趣为合作与安全制定切实可行的准则。我们将研究通过向量线性和准线性码的可靠性网络编码，并为分布式存储系统，网络节点合作，从磁盘故障恢复。在这里，局部性、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。隐形编码是基于可分辨性和分布匹配，其应用于编码调制的成形、隐写术和PLS。我们将发展分布匹配的理论，并为短和中等块长度设计好的代码，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.