Channel Modeling And Simulation In UAV Communication Scenarios

Recently,unmanned aerial vehicle(UAV)communications have attracted much attention for their potential in low cost and high flexibility applications,such as for wireless coverage,communication relay and data transmission.To improve the performance of UAV communication systems,multiple-input multiple-output(MIMO)technology becomes a research hotspot for various UAV communication systems.For the practical design and performance evaluation of UAV-MIMO communication systems,it is significant to mimic channel characteristics and develop corresponding accurate yet easy-to-use channel models.Based on the UAV three-dimensional(3D)MIMO two-cylinder regular geometric reference model,this paper first establishes deterministic and stochastic simulation models,consisting of line-of-sight component,single and double-bounced rays.By deriving the statistical characteristics of the simulation models and analyzing the simulation results,this paper proves that the two simulation models can fit well with the statistical characteristics of the reference model while reducing the computational complexity.Thus,the practicability of the simulation models is verified.On this basis,by imposing time-varying angular parameters,this paper proposes a UAV 3D MIMO non-stationary two-cylinder channel reference model and corresponding simulation models.Firstly,this model considers ground-reflection component.Secondly,based on the proposed model,some important channel statistical characteristics are derived and thoroughly investigated in this paper,including spacetime correlation function,Doppler power spectral density,envelope level crossing rate and average fade duration.In addition,this model has the ability to investigate the influence of some unique UAV-related parameters(e.g.,the UAV's moving direction,height,and speed)on channel characteristics and non-stationarity.Excellent agreement is achieved between the reference model and simulation models,demonstrating the feasibility of simulation models as well as the correctness of theoretical derivations.At the same time,since the ground station is assumed to be mobile,the proposed model is general and suitable for UAV-aided vehicular communication scenarios.Based on the above work,this paper further proposes a UAV 3D massive MIMO non-stationary irregular geometric model.The birth-death process is used to model the spatial doubly temporal non-stationarity.This paper innovatively introduces the impact factor of UAV into the transition probability of the birth and death process,thereby correcting the space-time non-stationarity in UAV wireless communication scenarios.Based on the proposed model,some statistical characteristics are deduced and thoroughly studied in this paper.Some numerical analysis and simulation results are given,and the impact of UAV-related parameters on channel characteristics and nonstationarity is investigated,which provides certain reference for the design of UAV massive MIMO communication systems.Finally,the practicability and accuracy of the proposed model is confirmed by the excellent fitting to actual measurement data.In summary,this paper mainly studies the channel modeling problem in the UAV communication scenarios,and proposes UAV 3D MIMO two-cylinder regular geometric simulation model,UAV 3D MIMO non-stationary two-cylinder channel model and UAV 3D massive MIMO non-stationary irregular geometric model.And the channel models are verified by simulation experiments.