Study On UWB Signal Propagation Characteristics In Indoor Environments Based On A Hybrid Method Of TD-RTM And FDTD

With the rapid development of wireless communication technology and the fifth generation of mobile communication put forward,in the field of modern wireless communication,large bandwidth and high communication rate has become an indispensable demand for wireless communication applications.Compared to the traditional narrowband communication systems,ultra-wideband(UWB)communication system has the advantages of large bandwidth,high transmission rate and anti multipath fading etc.In the new generation of wireless communication technology,UWB has a larger space for development and broad prospects in indoor wireless communication especially.In order to study the propagation characteristics of UWB radio channel in indoor environments accurately,the research on characteristics of UWB indoor radio channels is crucial.In this thesis,the hybrid algorithm based on time domain ray tracing method(TD-RTM)and finite difference time domain(FDTD)is used to research and analyze the propagation characteristics of UWB indoor radio channels.The main research contents and contributions are as follows:(1)In this thesis,the research status of UWB wireless channel is summarized.Then,the basis propagation mechanism,measurement technology,characteristic parameters and the typical models of UWB are briefly described.(2)The principle of time domain ray tracing method and finite difference time domain method(FDTD)are expounded in detail,and the process of two algorithms hybrid implementation is mainly introduced.Then,the hybrid algorithm is used to simulate the propagation characteristics of UWB in indoor simple environment,and it is compared with the data in the literature,which verifies the correctness of the hybrid algorithm.(3)The propagation characteristics of UWB signals in typical indoor corridors and indoor typical laboratory environments are simulated and analyzed.The propagation characteristics of UWB signal in different environments are analyzed through received power,power delay profile,path loss and other parameters.The transmission characteristics of UWB signals in different environments are analyzed by receiving power,power delay expansion,path loss and other parameters.It is found that in the propagation of the corridor environment,the signal intensity attenuates slowly because of the influence of the waveguide effect on the UWB signal which is propagated along the corridor direction.When the UWB signal propagates in the indoor laboratory,the direct signal with the strongest signal intensity is the first arrival of LOS propagation.The reflection propagation is the main mode of UWB signal propagation under the condition of NLOS.(4)According to the complex indoor environment,the UWB signal characteristics of complex indoor office environment and the complex indoor floor environment are researched through modelling and simulation.In this thesis,different transmit antennas,antennas polarization,diffraction and transmission depth calculation,and the influences of environmental electromagnetic parameters are also analyzed.Research on UWB signal has a penetrating ability and transmission is the main mode in non-of-sight propagation.The parameters such as the received power and time delay of UWB signal are significantly influenced by the electrical parameters of indoor environment,and different antenna polarization also has a certain effect on the time delay of UWB signal.