The Research Of Random Access Procedure In LTE System

LTE,long-term Evolution program is the evolution of 3G,is a more mature and current research which has a wide application prospect in wireless access technology domain.With the popularization and development of personal communications,wireless communication system in the number of user equipment will be more and more,resulting in the area under the heavy load,lead to network congestion.Due to cellular network business load ability is limited,how to make a lot of user equipment successfully access networks will become a key research direction.This thesis introduces the background knowledge and basic concept of random accessing process.Then,the processing procedure of random accessing in MAC layer was analyzed in detail.To network congestion in LTE system with the high access delay and high collision rate of a random access,the overload control scheme is proposed.Specific work is as follows:1.Research the whole process of the 3 GPP protocol random access process and design the functional structure and process of random access procedure in MAC layer on the basis of the protocol.2.Aiming at the condition of the network congestion and system overload,the overload control scheme is proposed,the base station firstly estimate the current load of network,then adjust the random access time-frequency resources and access threshold according to load condition,thus improving resource utilization and the success rate of random access.This thesis designs the LTE random access function at the MAC layer architecture,then the random access channel is modeled and simulated,this thesis proposes a random access overload control scheme at the MAC layer,and added it to the simulation platform,then Matlab simulation and performance analysis are carried out.