The Implement Of Channel Model For ITU-R IMT-2020 And Research On Spatial Consistency

Iin a mobile communication system,a channel refers to a signal transmis-sion path in space and belongs to the under-lying core module of the system.The transmission of wireless signals in space will experience fading due to the sur-rounding environment.The study of channel models is based on mathematical modeling to describe this fading characteristics.With the development of the fifth generation of mobile communication(5G)technology,people's require-?ments for communication quality continue to rise.This also brings challenges to the study of channel models.A new generation of communication systems requires a channel model that more accurately simulates the actual spatial fading characteristics.Therefore,based on the IMT-2020 channel standard issued by the International Telecommunication Union Radio communication sector(ITU-R),this paper studies the channel model simulation implementation and spatial consistency(SC).The main research work has the following three aspects:1.Theoretical study of channel model and simulation platform engineer-ing implementation.Most of the channel models proposed by existing channel standard documents are geometry-based stochastic channel mod-els(GB SM).Through actual measurement,the data of the spatial transmis-sion signal that experiences the small scale fading is obtained.Statistical analysis is performed to extract the characteristic parameters of the chan-nel.The GB SM model algorithm uses the statistical distribution to gener-ate the channel impulse response in a specific scene based on the channel characteristic parameters.After expounding the standard channel model theory,this paper designs a model simulation platform framework.The simulation platform is built on the basis of Matlab simulation software.It adopts modular design ideas,including antenna module,network layout module,large-scale parameter generation module,small-scale parameter generation module and channel coefficient generation module.The over-all data flow of the model is clear,and intermediate data about the channel model can be obtained quickly in the simulation process.At the same time,the platform is also easy to extend new feature modules.2.Algorithmic research and engineering implementation of spatial consis-tency.Spatial consistency is an important feature of 5G millimeter-wave channels,and its research results can be applied to beam tracking tech-nology.This paper first expounds three models for spatial consistency proposed by major standards organizations.At the same time,the sim-ulation project is implemented for ITU-R using the spatially consistent random variable model and the small-scale parameter spatial consistency algorithm I(SC Algorithm-I).Based on the standard channel simulation platform,spatial consistency is introduced by modifying the network lay-out,small-scale parameter generation and channel coefficient generation.It is necessary to rewrite the modified code file to get the spatial consis-tency module.3.Calibration of the channel simulation platform and analysis of the effects of spatial consistency.The existing channel simulation platform calibra-tion process is relatively complete.The main research work is the en-gineering implementation of the calibration process,and then combined with the calibration data given by other companies to analyze the output of the platform.The final calibration results also show that the output of the simulation platform is within the tolerance range and is consistent with other companies' platforms.Secondly,based on the simulation results of spatial consistency,the characteristics of the delay and angle charac-teristics of multipath clusters are analyzed as they move with the mobile station.Compared with the simulation results without spatial consistency,under the influence of the spatial consistency algorithm,the characteristic changes of the multipath clusters outputted by the platform are continuous.The three main tasks of this paper are all around the IMT-2020 channel model.Through the combination of theory and engineering,we can understand the model more deeply.The design idea of the simulation platform can help the development of the subsequent system simulation platform.At the same time,the research and effect analysis of spatial consistency algorithms will also contribute to the development of beam tracking technology.