Design And Research On Q-band Transceiver System For Train-to-train Direct Communication In Urban Rail

The vehicle to vehicle(V2V)communication technology and application is a new technology in the field of traffic mobile communication recently.The V2 V communication is an important part of vehicle ad hoc network,intelligent transportation and 5G communication in the automotive field,which has been studied as a hot spot.In the field of urban rail transit,train to train(T2T)communication is required as an emergency and redundant technology to ensure the safety of train operation in special situations.At the same time,the advantages of T2 T communication can also be demonstrated such as on-board control system,minimization of trackside equipment and minimization of communication delay.However,in the subway environment,due to the enclosed space,there will be multipath effects and waveguide effects in the process of electromagnetic wave propagation.The existence of multipath effect will cause serious attenuation of electromagnetic waves,which is related to the safety of urban rail operation.It is necessary to delay and phase adjust the received multipath signals,and selectively combine them to transform multipath signals into favorable signals to improve signal noise compare.The existence of the waveguide effect will have a certain selectivity to the frequency of the electromagnetic wave.The higher the frequency of the electromagnetic wave,the more obvious the waveguide effect and the smaller the attenuation.Therefore,in order to improve the reliability and security of urban rail T2 T direct communication,it is necessary to carry out research on Rake receiving technology and millimeter-wave transceiver system.The research focus of this thesis mainly includes:First of all,taking the T2 T communication environment of urban rail tunnel as the research background,this thesis designs the selection scheme of communication frequency band and range of T2 T communication.In the meantime,the calculation scheme of the slope communication distance is proposed to obtain the appropriate slope height and slope communication distance.According to the selected frequency band,the structure of Q-band wireless communication system is designed,which lays a foundation for the design of components of the following wireless communication system.According to the previous small-scale channel fading analysis,the Rake receiving technology is used for urban rail,which improves the communication quality.Secondly,the improved large-scale model of electromagnetic wave slope propagation adds the influence factors of tunnel humid environment and wet tunnel wall,and the simulation results of the improved model are compared with the Q-band radio wave propagation model of slope tunnel constructed by the simulation software Wireless Insite.The relationship between the polarization mode of antenna,bending degree,slope,whether there are pedestrians or not,space size and radio wave attenuation is analyzed by simulation.Finally,according to the above Q-band wireless communication system structure,large and small-scale fading analysis,design index requirements,the power divider,amplifier,mixer and other components of the wireless communication system are designed and simulated by ADS RF simulation software.The real object is made according to the design parameters of the power divider.After debugging,the test results are compared with the simulation results.At the same time,the system level link simulation is carried out for the wireless communication system.