交叉熵迭代辅助的跳时图案估计与多跳相干合并算法  

Cross-Entropy Iteration Aided Time-Hopping Pattern Estimation and Multi-hop Coherent Combining Algorithm

作　　者：苗夏箐[1] 吴睿 岳平越 张瑞[1] 王帅[1] 潘高峰 MIAO Xiaqing;WU Rui;YUE Pingyue;ZHANG Rui;WANG Shuai;PAN Gaofeng(School of Cyberspace Science and Technology Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学网络空间安全学院,北京100081

出　　处：《电子与信息学报》2025年第2期480-489,共10页Journal of Electronics & Information Technology

摘　　要：作为全球化通信网络的重要组成部分,卫星通信因其能够实现全球无缝覆盖和构建天地一体化信息网络而备受关注。跳时(TH)作为一种常用的卫星通信方式,具备强大的抗干扰能力、灵活的频谱利用和高安全性。该文提出一种适用于卫星通信的TH图案随机变化系统,以进一步增强数据传输过程的安全性。针对发射功率受限的问题,该文提出多跳信号相干合并策略,并进一步在该策略指导下,面对接收信号信噪比(SNR)低的约束,提出了交叉熵(CE)迭代辅助的跳时图案与多跳载波相位联合估计算法,以合并信噪比损失为目标函数,自适应调整待估参数的概率分布,从而快速收敛至最优解附近。仿真实验证明了该算法在迭代收敛速度、参数估计误差以及合并解调误码率等方面的优异性能。与传统算法相比,所提算法在保持较低复杂度的同时,误码率(BER)性能接近理论最优,有效提高了卫星TH通信系统在复杂环境下的稳定性和可靠性。Objective:As a vital component of the global communication network,satellite communication attracts significant attention for its capacity to provide seamless global coverage and establish an integrated spaceground information network.Time-Hopping(TH),a widely used technique in satellite communication,is distinguished by its strong anti-jamming capabilities,flexible spectrum utilization,and high security levels.In an effort to enhance data transmission security,a system utilizing randomly varying TH patterns has been developed.To tackle the challenge of limited transmission power,symbols are distributed across different time slots and repeatedly transmitted according to random TH patterns.At the receiver end,a coherent combining strategy is implemented for signals originating from multiple time slots.To minimize Signal-to-Noise Ratio(SNR)loss during this combining process,precise estimation of TH patterns and multi-hop carrier phases is essential.The randomness of the TH patterns and multi-hop carrier phases further complicates parameter estimation by increasing its dimensionality.Additionally,the low transmission power leads to low-SNR conditions for the received signals in each time slot,complicating parameter estimation even more.Traditional exhaustive search methods are hindered by high computational complexity,highlighting the pressing need for low-complexity multidimensional parameter estimation techniques tailored specifically for TH communication systems.Methods:Firstly,a TH communication system featuring randomly varying TH patterns is developed,where the time slot index of the signal in each time frame is determined by the TH code.Both parties involved in the communication agree that this TH code will change randomly within a specified range.Building on this foundation,a mathematical model for estimating TH patterns and multi-hop carrier phases is derived from the perspective of maximum likelihood estimation,framing it as a multidimensional nonlinear optimization problem.Moreover,guided by a coherent co

关 键 词：跳时通信 多维参数联合估计 跳时图案估计 交叉熵 相干合并 

分 类 号：TN92[电子电信—通信与信息系统]