LTE Physical Layer Decode Software System For Spectrum Auditing

With the rapid development of mobile communication technology,the 4th generation mobile communication signals,LTE standard signals,have been fully deployed.The explosion of data volume and massive connection caused the shortage of spectrum resoursces.In order to cope with the problem of the shortage of spectrum resources,the first problem that needs to be solved is to effectively detect the current requency band,and then the way of resource allocation is proposed.Therefore,4G network frequency evaluation system is imminent.In this thesis,physical layer decoding of common channel is carried out for LTE network,the occupancy position resource of each channel is calculated from the perspective of physical symbol,and the information of common channel is decoded.At the same time,this thesis also provides an interface for decoding the 5G physical channel while decoding the LTE physical channel.The improvement based on this system is shown in the last "5G second-stage test" in this thesis so that we can get information of 5G physical channel and characteristics of the signal.For the convenience of matrix operations,Viterbi decoding,data deinterlacing and other mathematical calculation,we choose MATLAB platform to complete the software development.The first chapter of this thesis introduces the development of wireless communications and the current situation of the spectrum shortage,the second chapter describes the entire protocol stack and network architecture of LTE.The third chapter analyzes the physical channel characteristics of two LTE signals in TDD mode and FDD mode,introduces the general module of each channel coding in the physical layer in detail,and elaborates the channel estimation and MIMO detection Algorithm and MATLAB implementation used in this thesis.Chapter four presents the overall framework of downlink decoding in LTE physical layer,and gives the detailed decoding flow of each channel from synchronous channel,physical broadcast channel,physical control format information indicator channel and physical control channel.At the end of the fourth chapter,the thesis presents the decoding results of LTE software system,including common channel system information and occupied resources,and shows the result of the system's extended detection of 5G signals.Finally,this thesis gives the future direction of improvement of 5G signal based on this system.