面向近海船岸通信的非平稳信道测量与多状态建模

      Non-Stationary Channel Measurement and Multi-State Modeling for Ship-to-Shore Communications

      • 摘要: 针对近海船岸无线信道非平稳特性刻画不足的问题,本文基于近海720 MHz频段的宽带信道实测数据,开展了近海岸船非平稳信道特性分析与统计建模研究。首先,采用局部散射函数(Local Scattering Function, LSF)时域相关系数方法对岸船信道的非平稳性进行定量分析,测得平均稳态时间约为1.35 s,据此确定了信道参数提取的统计窗口。进一步地,提出了一种近海岸船非平稳信道联合建模方法:利用高斯混合模型(Gaussian Mixture Models, GMM)对提取的最强径莱斯<inline-graphic xlink:href="b8389ffd43454a0284f4b9e066de60b0.xml/img_1.wmf" width="12.0" height="12.0" ></inline-graphic>因子和对数均方根时延扩展进行聚类分析,将信道划分为动态散射和稳态视距两种典型状态;在此基础上,构建二状态马尔可夫链模型,刻画近海岸船信道在不同状态间的动态切换规律,结果表明船只靠近岸边时,信道以稳态视距为主,远离岸边时呈现两种状态交替的特征;针对两种传播状态,分别建立抽头延时线(Tapped Delay Line, TDL)模型以表征其多径衰落特性。仿真与实测对比结果表明,该模型能准确表征近海岸船信道的时变非平稳特征,可为海上通信系统的设计与性能评估提供理论支撑。

         

        Abstract: To address the insufficient characterization of non-stationary properties in ship-to-shore channels, this paper presents a comprehensive analysis and statistical modeling study based on broadband measurements at 720 MHz in maritime environments. First, the channel non-stationarity is quantitatively analyzed using a time-domain correlation coefficient method based on the Local Scattering Function (LSF). The measured average stationary time of approximately 1.35 s serves as the basis for determining the statistical window for parameter extraction. Subsequently, a joint non-stationary modeling method is proposed. Gaussian Mixture Models (GMM) cluster the Rician K-factor of the strongest path and logarithmic Root Mean Square (RMS) delay spread to classify the channel into dynamic scattering and stable Line-of-Sight (LoS) states. A two-state Markov chain model then characterizes the dynamic transitions, revealing that the stable LoS state dominates in near-shore regions while an alternating pattern emerges offshore. Finally, Tapped Delay Line (TDL) models are established for each state to capture their specific multipath fading characteristics. Simulation results demonstrate that the proposed model accurately reproduces the time-varying non-stationary features of ship-to-shore channels, providing theoretical support for the design and evaluation of maritime communication systems.

         

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