ArrayTrack: A Fine-Grained Indoor Location System
分类： Software defined Radio
Using GNU Radio for Signal Phase Measurements
Using GNU Radio for Signal Phase Measurements
SDR数模转换芯片相关的技术参数手册
常用的芯片技术参数PDF手册
继续阅读SDR数模转换芯片相关的技术参数手册
Determining RF Angle of Arrival Using COTS Antenna Arrays: A Field Evaluation
Determining RF Angle of Arrival Using COTS
Antenna Arrays: A Field Evaluation
继续阅读Determining RF Angle of Arrival Using COTS Antenna Arrays: A Field Evaluation
ubuntu 16.04规避srsLTE报告”Sequence number synch failure“的BUG
参考ubuntu 16.04系统LimeSDR使用srsLTE搭建LTE实验环境构建实验环境,在实际运行时候，手机设备无法正常连接到基站，报告如下错误信息：
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 |
Received Attach Request Attach Request -- IMSI-style attach request Attach Request -- UE is already attached.Attach request -- IMSI: 208920100001100 Attach request -- eNB-UE S1AP Id: 3, MME-UE S1AP Id: 3 Attach request -- Attach type: 2 Attach Request -- UE Network Capabilities EEA: 11110000 Attach Request -- UE Network Capabilities EIA: 11110000 Attach Request -- MS Network Capabilities Present: true PDN Connectivity Request -- EPS Bearer Identity requested: 0 PDN Connectivity Request -- Procedure Transaction Id: 1 PDN Connectivity Request -- ESM Information Transfer requested: false Downlink NAS: Sending Authentication Request Plain UL NAS: Authentication Failure Sequence number synch failure Downlink NAS: Sent Authentication Request DL NAS: Sent Downlink NAS Message. DL NAS Count=0, UL NAS count=1 DL NAS: MME UE S1AP id 3 Plain UL NAS: Authentication Failure Sequence number synch failure Downlink NAS: Sent Authentication Request DL NAS: Sent Downlink NAS Message. DL NAS Count=0, UL NAS count=2 DL NAS: MME UE S1AP id 3 Received UE Context Release Request. MME-UE S1AP Id 3 UE is not ECM connected. No need to release S1-U. MME UE S1AP Id 3 UE is ECM IDLE. |
初步分析BUG的原因是如下函数在重新生成同步序列号的时候出现错误：
|
1 2 |
bool resync_sqn_milenage(uint64_t imsi, uint8_t *auts) |
目前还在分析，目前出现这个现象的时候，当EPC退出时候，应用一定向user_db.csv回写000000001b02，一旦出现这个数字，我们就没办法注册设备了。
目前的应对办法是把user_db.csv最后的SQN，要比设备最后一次通信记录的数据号大，如果SQN数字复位，可以让设备关机，应该就从0开始了。此问题还在持续跟进中。
ubuntu 16.04用HackRF和Gqrx来听FM广播
|
1 2 3 4 5 6 7 |
$ sudo apt-get install hackrf $ sudo apt-get install gqrx-sdr #gqrx的配置文件在~/.config/gqrx目录下，如果出现问题，直接删除这个目录即可 $ sudo gqrx |
SecureAngle: Improving Wireless Security Using Angle-of-Arrival Information
SecureAngle: Improving Wireless Security Using
Angle-of-Arrival Information
继续阅读SecureAngle: Improving Wireless Security Using Angle-of-Arrival Information
TIMING-BASED LOCATION ESTIMATION FOR OFDM SIGNALS WITH APPLICATIONS IN LTE, WLAN AND WIMAX
TIMING-BASED LOCATION ESTIMATION FOR OFDM SIGNALS WITH APPLICATIONS IN LTE, WLAN AND WIMAX
继续阅读TIMING-BASED LOCATION ESTIMATION FOR OFDM SIGNALS WITH APPLICATIONS IN LTE, WLAN AND WIMAX
窄带信号&模拟信号的带宽
DOA estimation based on MUSIC algorithm
DOA estimation based on MUSIC algorithm