5G-SA模式下随机接入过程的监测与信息提取  

Monitoring and Information Extraction of Random Access Process in 5G-SA Mode

作　　者：吴聪 石荣 邓科 WU Cong;SHI Rong;DENG Ke(Science and Technology on Electronic Information Control Laboratory,Chengdu 610036,China)

机构地区：[1]电子信息控制重点实验室,成都610036

出　　处：《电讯技术》2022年第2期191-198,共8页Telecommunication Engineering

摘　　要：随机接入过程是移动通信终端入网验证的关键步骤,对5G终端接入过程的交互信号进行非合作解调解码及信息提取是实施5G终端精准管控的重要前提。针对5G随机接入过程的信号时频特点,在非合作条件下利用时频快速搜索匹配检测方法准确获取随机接入过程中交互信号的时频位置,采用通信侦察中包络检波和时频分析等手段快速完成前导码及随机接入响应(Random Access Response,RAR)的信息提取,在此基础上通过RAR中的上行授权信息完成Msg3、Msg4的解调解码,提取出携带的信令信息。针对实际的中国电信5G终端与5G基站开展实验,在独立组网(Stand Alone,SA)模式下成功完成了随机接入过程的信号监测与交互码流信息的提取,验证了所用方法的有效性,适用于5G-NR信号侦收的工程应用。Random access process is a key step for mobile communication terminal to access verification.Non-cooperative demodulation,decoding and information extraction of interactive signals during 5G terminal access process are important prerequisites for implementing precise control of 5G terminal.In view of the time-frequency characteristics of signals in the 5G random access process,the time-frequency fast search and matching detection method is used to accurately obtain the time-frequency location of interactive signals under non-cooperative conditions.Envelopment detection and time-frequency analysis in communication reconnaissance are used to quickly extract the information of preamble and random access response(RAR).On this basis,the information of up link grant(UL Grant)in RAR is utilized to complete the demodulation and decoding of Msg3 and Msg4,and the carrying signaling information is acquired.Experiments are carried out on actual 5G terminal and 5G base station of China Telecom,and the signals monitoring of random access process and the extraction of interactive code stream information are successfully completed in stand alone(SA)mode to verify the effectiveness of the method.It is suitable for the engineering application of 5G-NR signals reconnaissance.

关 键 词：5G-SA模式 通信侦察 随机接入过程 交互信号 非合作解调解码 时频快速搜索 

分 类 号：TN971[电子电信—信号与信息处理]