Massive MIMO And Satellite Communication Channel Modeling

In recent years,with the rapid information globalization,the higher demands of wireless communication networks promote the development of 5th Generation(5G)wireless communication system.In 5G wireless communication systems,massive Multiple-Input Multiple-Output(MIMO)technology,which can effectively improve the system reliability,spectrum efficiency,and energy efficiency,is one of the key technologies in 5G wireless communication system.At the same time,in order to build the global coverage wireless communication network which can provide environmental monitoring,disaster warning.earth imaging and other services,satellite communication technology has become the key technology of the Beyond 5th Generation(B5G)wireless communication system with its advantages of convenient and rapid networking,good transmission quality,wide coverage,large communication capacity and seamless global connection.The application of these communication technologies makes 5G and B5G wireless communication channels show new characteristics compared with traditional channels,which brings great challenges to the channel modeling of 5G and B5G wireless communication systems.Accurate and efficient channel models which are indispensable for the performance evaluation and system design of wireless communication systems,play the fundamental and supporting role in physical layer research and development of wireless communication systems.Considering the shortcomings of existing channel models,this paper conducts extensive and in-depth research on the modeling and characteristics analysis of massive MIMO channels,satellite communication channels in 5G and B5G wireless communication systems.This paper summarizes the models of massive MIMO channels and satellite communication channels in 5G and B5G wireless communication systems,and points out the weakness of current works.Then it obtains the models of massive MIMO channels and satellite communication channels using the geometrv-based stochastic channel modeling method and Al-based predictive method with the measurement data and ray-tracing simulation data.The main contributions are as follows:1)Massive MIMO non-predictive channel modelThis paper proposes a three-dimensional(3D)non-stationary wideband confocal ellipsoid channel model for massive MIMO system with Uniform Planar Antenna(UPA).This model not only considers the time domain non-stationarity.but also combines the birth-death Markov process and seed algorithm to model the array domain non-stationarity in the UPA.Meanwhile,the selective cluster evolution and Cluster Evolution Areas(CEAs)are proposed by this model for the first time.Only the clusters in CEAs can undergo the birth-death evolution process of clusters.The model considers the spatial rotation of UPAs and realizes the spherical wave hypothesis through the accurate calculation of the azimuth direction and elevation direction of channel parameters such as delay,Doppler frequency,angle of departure(AoD)and angle of arrival(AoA).Based on the theoretical reference model,the corresponding simulation model is developed.The statistical characteristics of theoretical reference model and the simulation mode fit each other well.At the same time,this paper compares six channel models include geometry-based stochastic models(GBSMs).such as two-dimensional(2D)elliptical model.2D parabolic model,3D twin-cluster model,3D 5G unified model,3D ellipsoid model,and the most mature correlation-based stochastic models(CBSMs)--Kronecker birth-death model.Spatial cross-correlation functions(SCCFs)and channel capacities of the six models are calculated and analyzed.The SCCF of 3D channel model is slightly smaller than that of its corresponding 2D simplified models,and channel capacity of 3D channel model is larger than that of its corresponding 2D simplified models.2)Massive MIMO and millimeter wave channel characteristics predictive model for indoor scenarioIn this paper,a novel channel characteristics predictive model based on convolutional neural network for massive MIMO and millimeter wave indoor scenario is proposed.After training the convolutional neural network with limited data sets.11 channel characteristics can be predicted by inputting the 3D coordinates of Tx and Rx into the trained convolutional neural network.The channel characteristics predicted by convolutional neural network match well with those obtained by measurement data.The root mean square error and the probability density function of square error are also analyzed accurately.At the same time,five different ray-tracing data collection methods are used to summarize how to conduct data collection for obtaining better prediction,which has guiding significance for the data collection and data set generation in the wireless big data.3)Satellite communication non-predictive channel modelIn this paper.a Q band 3D channel model for satellite communication in high latitude region is proposed.Markov chain are adopted to model the shadow fading.The small-scale fading model is the GBSM in which the scatterer located on the spherical surface of the hemisphere.The simulation results show that the statistical characteristics of 3D channel simulation model match well with those of the corresponding theoretical model and the measurement data.4)Satellite communication predictive channel modelIn this paper.the satellite communication channel attenuation predictive model based on ANN is proposed according to the weather information.In particular,the probability of the absolute error between the predicted and measured fading data lower than 1 dB is as high as 98.85%.The proposed method can effectively improve the efficient and low-cost deployment of propagation impairment mitigation techniques,such as adaptive coding and modulation and dynamic power control,which can improve the transmission efficiency of satellite communication.In all,this paper investigates the channel of massive MIMO wireless communications and satellite communications.GBSMs and predictive channel models are proposed for massive MIMO wireless communication channels and satellite communication channels.The thesis has important guiding significance for implementation of 5G and B5G wireless communication system.