面向物理层信号溯源攻击的匿名预编码对抗机制研究

匿名通信在智慧医疗、车联网、军事等通信中有着广泛的应用，不同于用户安全设计，匿名通信旨在为合法用户提供高通信质量的同时，保证通信参与者的匿名性与隐蔽性。但现有匿名通信研究着眼于协议上层，对用户匿名性在物理层泄露威胁的关注有限，缺乏面向物理层溯源攻击的对抗机制研究。聚焦用户向接入点发送信号又需保持匿名性的问题，本项目围绕用户高匿名性、通信高可靠性的目标，拟从底层研究并揭示信号溯源攻击机理，为接入点建立依据接收信号、环境噪声统计特性的溯源攻击方法；研究并建立面向溯源攻击的物理层防御机制，为用户设计匿名预编码算法，提高用户匿名性的同时确保多路空间复用数据流的高接收信噪比，合理均衡用户匿名性与通信可靠性；针对低分辨率数模转换器与非完美信道估计，研究并设计鲁棒匿名预编码算法，提高匿名通信在实际通信场景的适用性。本项目为物理层匿名通信奠定一定理论基础，促进匿名预编码这一研究领域的发展。

Anonymous communications have a wide range of applications in e-Health, vehicle-to-everything and military communications. Different from conventional security-orientated designs, anonymous communications aim to guarantee the communication quality of the legitimate users, and meanwhile to conceal the identities of communication parties or the specific users’ participation during the communications. The existing anonymity-related techniques are only designated at upper layers of networks, ignoring the risk of anonymity leakage at physical layer (PHY). This project focuses on the uplink communication scenario where users wish to anonymously send signal to an access point (AP). In particular, while cooperating with senders for communication signal processing, the AP also tries to unmask the senders’ anonymity. Hence, this project aims to achieve both high anonymity and communication reliability, where the main contents include: (1) studying the PHY based signal traceback mechanism, and designing signal traceback attack that only depends on the statistical attributes of the received signal and noise; (2) proposing anonymous precoding technique to counteract the signal traceback attack without loss of high signal-to-interference-and-ratio performance at the AP, and making a good tradeoff between the anonymity and communication reliability. (3) proposing robust anonymous precoding against low-resolution digital-to-analog converter and imperfect channel estimation and improving the applicability of the anonymous communications in practical communication scenarios. This project provides fundamentals for PHY anonymous communications, and prompts the development of anonymous precoding, which hold the promise of exciting research in the years to come.