Research On Adaptive Coding And Modulation Technology And Performance Of Physical Uplink And Downlink Shared Channel For Broadband Wireless Trunking System

The purpose of the broadband wireless trunking network system is to meet more stringent requirements for the reliability,security,real-time performance,and high efficiency of data transmission in the construction of smart cities.However,in the wireless mobile communication system,the channel is time-varying.The adaptive modulation and coding(AMC)is a promising technology to improve the transmission efficiency over the channel with time-varying and limited frequence resource.In this thesis,we study the adaptive modulation and coding(AMC)technology to improve the transmission efficiency of the wireless trunking system.In order to research AMC technology,we firstly build the simulation platform of wireless trunking system and give a lot of simulations.Then we study two adaptive modulation and coding schemes:the traditional AMC scheme and the KNN-based AMC scheme.Finally,we give the simulation results to compare the performance of the two AMC schemes.The details are given as follows.The first chapter introduces the background and significance of the research content of the thesis.The technologies involved in this thesis are briefly introduced,and the organization of the thesis are finally given.The second chapter studies the key technologies of the uplink shared channel link in the broadband wireless trunking network,introduces the functions and principles of the key modules in detail,and gives a lot of simulations and analysis on the uplink channel data transmission in the second part of this chapter.In the third chapter,the downlink in the broadband wireless trunking network system is briefly introduced firstly,then the correlation between CQI and modulation order and coding rate,traditional AMC scheme are described.Then,based on the link,simulation and analysis of downlink non-adaptive data transmission are simulated.Finally,the performance is given for the traditional AMC scheme in downlink channel.In the fourth chapter,we propose a new AMC scheme based on K-nearest neighbor algorithm in machine learning.Finally,the two AMC schemes are also compared and analyzed.The fifth chapter summarizes the thesis and gives the potential technologies to further improve the performance of AMC schemes on the wireless trunking network.