Channel Characteristics Analysis And Modeling For THz Wireless Communications Toward 6G

In recent years,with the rapid development of the Internet of Things,more smart devices have been accessed to wireless communication networks.To meet people's increasing demand for network traffic,larger bandwidth and higher data transmission rate are required.After the 5G standard has been formulated and the momentum for commercialization is gradually developed,the research of 6G is on the agenda.As one of the key techologies of the 6G mobile communications,terahertz has abundant frequency band resources,and can provide more than 20 GHz bandwidth and Tbps communication data rata.The performance of the mobile communication system is affected by the channel characteristics.It is necessary to have a full understanding of the channel characteristics and a comprehensive study of the channel to use new frequency bands and design new systems.The channel models can use mathematical methods to describe the channels,and provide evaluation methods and simulation environment for communication technology research,system scheme designing,and network deployment,etc.Firstly,in this paper,existing communication test systems are list.The large-scale fading of terahertz communication channels is introduced,calculating the free space path loss and molecular absorption loss in indoor scenarios,and describing the dry air attenuation,water vapor attenuation,rain and cloud attenuation in outdoor scenarios,The main reason of small-scale fading in terahertz communications is multipath propagation when the transmitters and receivers are still.Then the propagation path types that need to be considered in terahertz communications are explainedSecondly,in this paper,an improved ellipsoid-double-sphere geometry based stochastic channel model is proposed,then the corresponding channel characteristic parameters are derived.According to the comparison of simulation results and measurement data,the validity of the proposed channel model is verified,proving that the improved channel model is more suitable than the original model in indoor terahertz communication scenariosFinally,in this paper,the ray tracing algorithm is used to study the terahertz communication channels in the indoor office scenarios.The communication scenarios is built based on the Wireless InSite software,introducing the influence of the rough plane on the channels.The power distribution characteristics of the angle of arrival of the receivers are obtained.The channel transfer functions under different correlation lengths and height standard deviations are also gotten to observe the effect of the change in plane roughness on the received signalIn this paper,the indoor office scenario is built using Wireless InSite software.Introducing the influence of rough plane on channel,the AoA power distributions of different receivers and CTFs with different correlation lengths and height standard deviations are obtained.The effect of the change of the plane roughness on the received signals is analyzed.