Abstract: The openness and broadcast nature of wireless communication make transmitted signals vulnerable to illegal eavesdropping and malicious attacks. Physical layer security becomes an effective way to enhance confidentiality, but existing methods have limited key space, fixed encryption parameters, and insufficient secrecy performance, so they cannot counter stronger attackers. To improve secure transmission at the physical layer, this paper proposes a novel multi-domain joint modulation secure communication method with dynamic control by a three-dimensional chaotic map. The method introduces sine, cosine, and exponential nonlinear terms into the Hénon map and constructs a three-dimensional Hénon-Sine-Cosine-Exponent chaotic mapping (3D-HSCE). The paper verifies its chaotic properties by bifurcation diagrams, Lyapunov exponent spectra, and phase portraits. The method uses polarization modulation (PM) to expand the modulation dimension and combines it with the Generalized Multi-Parameter Weighted Fractional Fourier Transform (GMPWFRFT) to scramble the signal constellation. The method applies 3D-HSCE to encrypt the constellation amplitude and phase and designs a state-feedback update mechanism for the initial values to dynamically regulate the key parameters. The system thus achieves dynamic constellation encryption. Simulation results show that the encrypted signal exhibits Gaussian-like characteristics. The key space reaches 2326 and the scheme shows high sensitivity and strong security. Even when the eavesdropper key differs from the correct key by 10-16 or 10-15, the bit error rate remains close to 0.5 and no valid information is recoverable. The method significantly strengthens resistance to parameter-scanning and modulation-recognition attacks. Compared with the 2D-HCE-DDL-GMPWFRFT method, the key space increases by 2108 times. When SNR = 10 dB, the system bit error rate decreases by about two orders of magnitude. Under three parameter conditions, the system secrecy capacity increases by about 332.5%, 45.8%, and 6.7%. The proposed method therefore enables secure transmission at the physical layer.

摘要： 无线通信的开放性和广播性使得传输信号极易受到非法窃听或恶意攻击的威胁，尽管近年来物理层安全通信技术已成为提升无线传输保密性的有效途径，但现有方法普遍存在密钥空间受限、加密参数固定以及信号保密性能不足等问题，难以有效抵御窃听者日益增强的攻击能力。因此，为了提升无线通信物理层的安全传输性能，该文提出一种新型三维混沌映射动态调控的多域联合调制安全通信方法。通过向Hénon映射中引入正弦、余弦和指数非线性项，构建了三维埃农正余弦指数混沌映射函数(3D-HSCE)，并借助分岔图、Lyapunov指数谱与相图验证了其混沌特性。随后，引入极化调制(PM)以扩展信号调制维度，并结合广义多参数加权分数傅里叶变换(GMPWFRFT)进行信号星座扰乱。此外，还利用3D-HSCE混沌映射来实施信号星座幅相加密，并设计了其初始值的状态反馈更新机制来动态调控系统密钥参数，从而实现了信号星座的动态加密。仿真结果表明，所提方法加密后的信号呈现类高斯分布特性，密钥空间可达2326，具备高敏感性与强安全性，即使窃听端密钥与正确密钥存在10-16或10-15的微小误差，其误比特率始终接近0.5，无法解密出任何有效信息，显著增强了系统抗参数扫描与调制识别攻击能力。与2D-HCE-DDL-GMPWFRFT方法相比，本文方法的密钥空间提升了2108倍，当SNR=10 dB时，系统误比特率下降了约2个量级，三种参数条件下的系统安全容量分别提升了约332.5%、45.8%、6.7%，故所提方法能够实现物理层的安全传输。