Research And Implemention Of Multi-User Access Technology Of Special-Using Small Base Station

Long Term Evolution,as the representative of the fourth generation mobile communication system,is not only widely used in daily communication,but also be used in media,education,security and other fields.Small base stations have also begun to enter the historical stage with LTE technology,which has high integration,flexible deployment and scalability,and can be fully used under some special situations.This paper mainly studies the access technology of small LTE base stations.On the one hand,considering the situation of many users accessing at the same time,compares and analyzes several access congestion control mechanisms through simulation;on the other hand,it designs and implements the terminal access process on the base station side from the software level.Firstly,this paper gives a brief introduction to the LTE network architecture and analyzes the random access process in detail.At the same time,the access process on the base station side is analyzed,the process of establishing RRC connection is introduced,and the access module is preliminarily designed.Secondly,the third chapter of this paper mainly studies the congestion control mechanism under multi-user access.The random access process is mathematically modeled,and the back-off mechanism and ACB mechanism are simulated and analyzed.On this basis,a load feedback mechanism based on ACB is proposed.Simulation results show that this mechanism can have higher access success rate and lower access delay when the load is the same.Meanwhile,an access channel resource adaptation mechanism is proposed,which can effectively reduce the access delay when the load is low.Subsequently,the fourth chapter of this paper is mainly aimed at the implementation of MAC layer and RRC layer access related modules.The MAC layer mainly designs the message interface module and the random access response module,including the design of the message structure and the realization of the function flow.It also incorporates the adaptive access control mechanism in Chapter 3.The RRC layer mainly designs and realizes the interface manager module and the terminal control module at the bottom level,designs the state machine for each submodule and the state transfer process,realizes the state transfer function,and analyzes the messaging process when each module is connected to the terminal as a whole.Finally,this paper deploys a small LTE base station test environment on the 9131 RDB hardware platform,and tests the terminal access process in conjunction with the core network,proving the feasibility and correctness of the design of the access module of the MAC layer and RRC layer.