基于FDTD的海面无线信道传播特性研究

发布时间：2018-07-01 18:45

本文选题：海洋通信 + 时域有限差分方法　；参考：《天津大学》2014年硕士论文

【摘要】：海洋无线通信信道特性十分复杂。海浪的随机性是影响海面无线信道特性的主要因素,其对信号的影响主要体现在能量衰减、多普勒频移等方面。构建稳定的海洋通信系统需要很好地了解海面信道特性。本文采用FDTD算法对海洋无线通信环境下的信号传播特性进行了研究和分析。首先,文章针对二维海面环境进行了建模分析,建模过程中采用修正的PM谱模型建立随风速变化的随机海面,研究无线信号在不同浪高环境下的传播特性。三维海面模型更能真实地反映信号在海面环境中的传播过程。进而,文章采用三维并行FDTD算法进行海面信道建模,基于MPI和OpenMP的三维并行算法有效地提高了FDTD仿真的精确性和仿真范围。通过对上述仿真方法得到的瞬时电磁分量数据分析,得到了在固定发射机和接收机位置的情况下,以频率和海浪高度作为参数的路径损耗和时延扩展等模型。本文的创新点在于将FDTD算法应用于海面无线信道传播特性的研究中,通过引进CPML边界条件,改善了边界吸收效率,提高了仿真数据的精确性。此外,本文还实现了基于MPI和OpenMP的三维并行FDTD算法,并应用于海面无线信号传播特性研究。三维并行FDTD算法的实现,不仅提高了数据仿真的精确性,而且使得该算法能有效地应用于较大区域的电磁仿真环境中。
[Abstract]:The characteristics of marine wireless communication channel are very complex. The randomness of ocean waves is the main factor that affects the wireless channel characteristics of sea surface, and its influence on the signal is mainly reflected in energy attenuation, Doppler frequency shift and so on. In order to build a stable ocean communication system, we need to understand the characteristics of the sea surface channel. In this paper, FDTD algorithm is used to study and analyze the characteristics of signal propagation in marine wireless communication environment. Firstly, the modeling of two-dimensional sea surface environment is carried out. In the process of modeling, the modified PM spectral model is used to establish the random sea surface with the change of wind speed, and the propagation characteristics of wireless signal in different wave height environment are studied. The three-dimensional sea surface model can more truly reflect the signal propagation process in the sea surface environment. Furthermore, 3D parallel FDTD algorithm is used to model the sea surface channel. The 3D parallel algorithm based on MPI and OpenMP can effectively improve the accuracy and simulation range of FDTD simulation. Based on the analysis of the instantaneous electromagnetic component data obtained by the above simulation methods, the path loss and delay spread models with frequency and wave height as parameters are obtained in the case of fixed transmitter and receiver position. The innovation of this paper lies in the application of FDTD algorithm to the study of the propagation characteristics of wireless channel on the sea surface. By introducing CPML boundary conditions, the boundary absorption efficiency is improved and the accuracy of simulation data is improved. In addition, the 3D parallel FDTD algorithm based on MPI and OpenMP is implemented in this paper, and it is applied to study the propagation characteristics of wireless signals on the sea surface. The implementation of 3D parallel FDTD algorithm not only improves the accuracy of data simulation, but also enables the algorithm to be effectively applied to the electromagnetic simulation environment in a large area.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN92

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