Title: A Secure Affine Frequency Division Multiplexing System for Next-Generation Wireless Communications Show Chinese title

Title: 一种用于下一代无线通信的安全仿射频分复用系统

Abstract: Affine frequency division multiplexing (AFDM) has garnered significant attention due to its superior performance in high-mobility scenarios, coupled with multiple waveform parameters that provide greater degrees of freedom for system design. This paper introduces a novel secure affine frequency division multiplexing (SE-AFDM) system, which advances prior designs by dynamically varying an AFDM pre-chirp parameter to enhance physical-layer security. In the SE-AFDM system, the pre-chirp parameter is dynamically generated from a codebook controlled by a long-period pseudo-noise (LPPN) sequence. Instead of applying spreading in the data domain, our parameter-domain spreading approach provides additional security while maintaining reliability and high spectrum efficiency. We also propose a synchronization framework to solve the problem of reliably and rapidly synchronizing the time-varying parameter in fast time-varying channels. The theoretical derivations prove that unsynchronized eavesdroppers cannot eliminate the nonlinear impact of the time-varying parameter and further provide useful guidance for codebook design. Simulation results demonstrate the security advantages of the proposed SE-AFDM system in high-mobility scenarios, while our hardware prototype validates the effectiveness of the proposed synchronization framework. Show Chinese abstract

Abstract: 仿射频分复用（AFDM）由于其在高移动性场景中的优越性能，以及多个波形参数为系统设计提供了更大的自由度，引起了广泛关注。 本文介绍了一种新型安全仿射频分复用（SE-AFDM）系统，该系统通过动态变化AFDM预啁啾参数来增强物理层安全性，从而改进了先前的设计。 在SE-AFDM系统中，预啁啾参数是从由长周期伪噪声（LPPN）序列控制的码本中动态生成的。 与在数据域中应用扩频不同，我们的参数域扩频方法在保持可靠性和高频谱效率的同时提供了额外的安全性。 我们还提出了一种同步框架，以解决在快速时变信道中可靠且快速同步时变参数的问题。 理论推导证明，未同步的窃听者无法消除时变参数的非线性影响，并进一步为码本设计提供了有用的指导。 仿真结果展示了所提出的SE-AFDM系统在高移动性场景中的安全优势，而我们的硬件原型验证了所提出同步框架的有效性。