Research On Key Technologies Of Broadband Transmission Based On Multiple Antenna Multiplexing

In modern communication technology Multiple-input multiple-output technology is a popular method to improve channel capacity,and the same to air-to-ground communication channels.To realize the theoretical channel capacity of MIMO under the air-to-ground communication channel,it is necessary to study the air-to-ground communication channel and the detection technology of MIMO signals.This article focuses on the key technologies of multi-antenna multiplexing broadband transmission in the air-to-ground communication environment,and conducts important research on the air-to-ground communication channels and channel equalization algorithms.The main research is as follows:First,for the air-to-ground communication channel,this paper proposes a geometric-based statistical model,modeling the four main paths of signal propagation in the air-to-ground communication channel through measured data.The free-space propagation model is used in the modeling of the direct path.In the modeling of the ground reflection path,the influence of the relative permittivity and conductivity of the ground on the reflection coefficient is discussed,and the unevenness of the ground is taken into consideration.In the modeling of the lateral reflection path,the reflector is set as a point reflector,and the opening direction and opening size of the reflector are exemplified by measured parameters,and the article focuses on the influence of the number and position distribution of reflectors.In the study of the scattering path,through the cloud model,the signal power is allocated to the signal with the same delay and different Doppler frequency,which realizes the expansion of the scattered component power at the Doppler frequency.Finally,the four paths are integrated to obtain the air-to-ground communication channel model,and the simulation of the air-to-ground communication scenario is completed by setting the corresponding parameters,which verifies the correctness of the model.Secondly,this paper also studies the signal detection algorithm of the V-BLAST model.Based on the QR decomposition algorithm,the MIMO MMSE-DFE model is given,and the best matrix coefficients of feedforward filter and feedback filter are obtained by derivation.In order to reduce the computational complexity of QR decomposition,this paper further studies the QR decomposition algorithm,and implements a low computational complexity QR iterative decomposition algorithm through an iterative way.In the air-to-ground communication channel,the complexity of the MIMO MMSE-DFE model is too high.Therefore,the MIMO MMSE-HDFE model is proposed.By comparing the computational complexity of the two models,it is proved that the MIMO MMSE-HDFE model has lower computational complexity under high-speed communication.Finally,the model was verified in the air-to-ground communication simulation channel environment,which proved the feasibility of the model in air-to-ground communication.