The Research And Implementation Of LTE Downlink Control Links Decoder Based On Software Defined Radio

Mobile communication technology has greatly promoted the development of society.As a quasi-fourth generation mobile communication standard,LTE has the advantages of flexible configuration,simple structure,high speed and low delay,and it is a hot topic in recent years.In the past,the research on LTE was usually based on the software simulation platform.However,software simulation could not fully simulate the complex wireless channel characteristics and network environment.At the same time,commercial LTE hardware development platforms are ex pensive and often not fully accessible due to factors such as commercial secrecy.Software defined radio(SDR),based on the general hardware platform,uses software algorithms to implement the coding and modulation processes of communication signals,which has become a convenient and efficient research platform for studying LTE related key technologies.Based on the GNU Radio and USRP,this paper designs and implements an LTE physical layer downlink control link air interface decod er.Specifically,we first introduces the protocol architecture and transmission procedure of LTE downlink control link.Then,we gives the overall design scheme of the LTE physical layer downlink decoding and each key decoding module(including the PSS/SSS decoding module,the PBCH decoding module,the PCFICH decoding module,the PHICH module and the PDCCH module).After that,the C-RNTI(Cellular Radio Network Temporary Identification)in downlink control link is studied,and a PDCCH monitored based C-RNTI decoding algorithm is proposed and implemented.Finally,the experimental test platform is built in the laboratory according to the related concepts and principles of the software radio platform,and the designed and implemented LTE physical layer downlink control link decoding experimental platform is tested.The test results show that the designed system can decode the LTE physical downlink control link.The channel is correctly decoded,and various system parameters included in the control channel are correctly acquired,including important information such as the central frequency,the system bandwith,the cell identity(Cell ID),the C-RNTI and so on.This system is of great significance for air interface monitoring and network optimization of LTE networks.