Research On The Key Technologies Of AeroMACS Fast Access

The domestic civil aviation transportation industry has developed rapidly in recent years.The Aeronautical Mobile Airport Communication System(AeroMACS)is a new type of high-speed and reliable mobile communication system that can meet civil aviation data.Transmission and emergency requirements,through this system,can provide better and more reliable data transmission services for airlines and airports.AeroMACS is a broadband wireless communication technology based on IEEE802.16e(WiMAX)standard.How to achieve fast access in WiMAX system and improve the efficiency of the system is one of the difficulties in studying WiMAX system.It is also the study of WiMAX system in thesis and the starting point for key technologies in the WiMAX system.The main objective of thesis is to solve the problem of how to realize fast access of WiMAX system.From the theoretical foundation layer,the following key technologies are researched and improved,including orthogonal frequency division multiple access(OFDMA)technology,cell search technology,and advanced antenna system(AAS)technology.The research work and main results of thesis are as follows:Firstly,study the IEEE802.16 e protocol and its key technology OFDMA,build the transmission simulation platform of WiMAX system in Matlab according to the protocol specification,and realize the transmission process of OFDMA system;study the characteristics of wireless mobile channel model and select the ITU suitable for its characteristics The ITU-R channel is applied to the IEEE802.16 e working environment and completes channel construction and simulation.Secondly,study the key process of mobile user access,namely the key technology of cell search,analyze the influence of different synchronization parameters on system performance,and research and simulate the specific process of cell search,which can not be correctly implemented for low SNR.Frame detection,which affects the access problem,proposes an improved dual correlation algorithm for blind channel estimation and equalization.The simulation verifies that the improved scheme can achieve better access in a low SNR environment.At last,study the key technologies of smart antennas that can significantly improve user access efficiency,analyzes the support of smart antenna technology in IEEE802.16 e protocol,introduces the leading code arrival angle estimation algorithm for WiMAX systems,and proposes a suitable low The improved algorithm of SNR is compared with the traditional angle of arrival estimation algorithm to verify the superiority of the algorithm.