Research And Simulation Of 5G Millimeter Wave Channel Model

With the development of the 5th Generation of Mobile Communication System(5G),some large data volume services are popular,such as virtual reality,driverless,and ultra high definition video streams.Higher requirements are placed on the overall performance of the communication system.However,the current channel model only supports low-frequency(sub-6 GHz)channel characteristics,and cannot meet the transmission characteristics of high-frequency,large-bandwidth,and large-sized antenna arrays of millimeter-wave massive MIMO.Therefore,it is necessary to establish an effective channel model that satisfies the actual propagation environment.In this thesis,the channel simulation model is based on the method of stochastic geometry.After verifying its accuracy,the channel model is simplified.The full text has carried out related research work on the accuracy and complexity of channel simulation modeling.1.Firstly,the technical background and research status of channel modeling are introduced,and the challenges brought by millimeter wave and massive MIMO technology to channel modeling are analyzed from modeling theory.In view of that the existing channel models cannot satisfy the propagation characteristics of 5G millimeter wave channel.Based on the channel model given by 3GPP TR 38.901,additional channel characteristics are added to ensure that the channel modeling conforms to the channel characteristics of millimeter-wave massive MIMO.2.The channel modeling is verified and analyzed.According to the calibration standard in the 3GPP TR 38.901 protocol,the large-scale fading and small-scale fading are simulated and verified respectively,and the processed simulation results are compared with the channel reference data provided in the 3GPP proposal.The coupling loss,signal to interference and noise ratio,the delay spread,angle spread and other indicators are verified and analyzed.At the same time,the effectiveness of the two high-frequency additional characteristics,oxygen loss and blocking model,is analyzed,and the accuracy of the channel model is verified.3.The channel modeling is simplified.In this thesis,the stochastic geometry modeling method is adopted,and the proposed channel model has higher accuracy and can be used to restore the propagation characteristics of the channel.However,large antenna arrays and plenty of random variables lead to computational complexity that is too high during the modeling process.In order to solve this problem,some modules are simplified in this thesis,and the complexity is reduced under the premise of satisfying the accuracy of the channel model.4.The convolution calculation is involved in the system simulation,the mismatch between path delay and system sampling interval has an impact on the performance of the communication system and the effectiveness of the channel model.In order to minimize the error and calculation time brought by the convolution operation as much as possible,the approximate substitution model of the original channel model is adopted without increasing the sampling rate of the system,so that the multipath delay is exactly an integer multiple of the sampling period.Based on the interpolation principle,this thesis proposes several channel model conversion schemes that effectively reduce the system simulation error.The accuracy and validity of the substitution model are verified by the simulation results of the 5G Physical Downlink Shared Channel(PDSCH)link.