Modeling And Verification On Tropospheric Scattering Communication Channels

Tropospheric scattering communication has important applications in military communications and many other fields with the characteristics of long one-hop distance,strong confidentiality and strong ability against environmental interference.The communication channel needs to be fully measured and analyzed before the communication system designed,and then the corresponding technical solutions can be selected according to actual needs.Due to the long channel link and complex characteristics of propagation,it is especially important to select a communication scheme suitable for the channel.The selection of communication scheme requires quantitative criteria,and the decoding performance of the receiver is used to distinguish the advantages and disadvantages of the scheme.Therefore,it is necessary to have a suitable scattering channel model for communication system simulation.In order to build a model that conforms to the characteristics of tropospheric scattering channel,we need to study the theory of electromagnetic wave propagation in the troposphere fir-st,and explain how the signal is scattered to the receiver from the microscopic level of a single scatterer.Then the channel loss,the multipath effect and the cause of the Doppler effect are estimated based on the characteristics of the scatterer,and then the basic theory for the study of the characteristics of the scatter channel is constructed.In this paper,I find a suitable model to simulate the attenuation coefficient in the scatter channel based on the existing scattering theory,and make statistical analysis to confirm the validity of the channel coefficient.Here the theorm of combined Tausworthe generator is used to construct a uniformly distributed random number,and the inverse normal Gaussian cumulative distribution function is used to map the standard normal distribution to simulate the channel noise,and then verifying the noise from statistical analysis and Monte Carlo simulation.The model simulation on the software platform is completed with the channel coefficient and noise.In order to verify the rationality of the model,the actual transmission under the MIMO system is simulated,and the results satisfy the theory.The target of this paper is to build a channel simulator based on FPGA platform and MIMO-SCFDE system.Starting from the top-level module,the article introduces the implementation of each sub-module,and explains control principle and protocol of host computer software.Finally,the decoding performance of different channel environments are simulated in the MIMO-SCFDE system.The design and implementation of this paper have been verified by rigorous simulation and finally applied to the communication system to verify the validity of the model.