Ray Tracing Based Wireless Channel Characteristic Analysis In Various Communication Scenarios

With the development of wireless communication technology and the innovation of the Internet devices,mobile data traffic has grown rapidly in few years,and its tendency shows exponential growth.The shortage of spectrum resource limits the data transmission speed as well as the access user number,causing huge conflicts between the demands of future communication.To solve this problem,novel communication technique and extension of available bandwidth is desired.Millimeter wave(mm Wave)is favored by researchers because of its abundant spectrum resources.Meanwhile,the unique characteristics of mmWave will bring challenges to exploitation.Besides,the creation of multiplexing and multiple access technology will maximize the utilization of existing spectrum resourcesAs a vital element of wireless communication system,wireless channel is necessarv to be studied,since its characteristics affect directly on the upper layer applications Channel modeling gives a concise and intuitive description of wireless channel by using mathematic model.Also,it can easily capture the channel features,providing theoretical foundation of the whole systemsRay tracing methods can analyze and predict electromagnetic wave propagation in specific propagation scenario according to geometry optics and diffraction theory.Ray tracing methods can get quick and accurate information about wireless channels,which has become a powerful tool for channel modeling and character analysis.The research on characteristic analysis in variable scenarios at multiple frequency bands are based on ray tracing.The main work is shown below:Large-scale channel characteristic analysis in outdoor scenarios at low frequency band:Typical urban and suburban scenarios are built in simulation platform,Wireless InSite.Propagation loss can be extracted from simulations results calculated at 500 MHz.A proper path loss and shadowins model is designed according to classical models.All parameters are obtained by fitting simulation databaseSmall-scale channel characteristic in indoor staircase scenario at mmWave band:A staircase simulation scenario is set up and the multipath component(MPC)information of each receiver positions at 60 GHz can be obtained by ray tracing.The variations of channel features like RMS DS.RMS AS.PDP.PAS are studied with the motion of receiving points.Besides,a directive single-lobe scattering model(DSM)is introduced in simulation procedure,and the channel characters are compared.Study on channel clustering algorithms:Several partition-based clustering algorithms and tracking algorithm are summarized.Classical fuzzy C-means algorithm is modified in order to suit the channel database.Clustering procedure is conduct in same database with modified FCM,KPM,IG-FCM and IG-KPM methods.And the performances of these methods are compared.The MCD based tracking algorithm is applied to define the cluster status when the receiver moves,so as to analysis the cluster birth-and-death process.