Jiao Xianjun (BH1RXH)'s tech blog - Categories/分类

radio
2014-10-28 I got class B certification of China HAM Radio
2014-10-01 听DRM无意中收听到的怪广播(weird audio when shortwave DRM listening)
2014-06-18 WiFi信号不好的几种尝试以及结果(WiFi Adapter test)
2013-11-10 数字化灵巧BPF初步设计和仿真(Digital BPF STM32)
2013-08-29 DVB电视棒(rtl2832 tuner 820t)的 DVB DMB-T DAB FM 搜索结果-立水桥 (scan report)
2013-08-09 上英国亚马逊买了个 morphy richards drm radio 收音机
2010-08-01 终于成功收听德广和俄罗斯的DRM短波广播(DRM shortwave radio receiving result - deutsche welle and Russia)
2008-07-05 DRM接收及matlab实验(DRM shortwave radio receiving experiment)
gps
2022-09-11 MSV-ATC卫星移动通信技术研究
2017-05-01 Study on faking GPS signal for iPhone 6 iPhone 6s iPhone SE iPhone 7
2014-05-28 Some efforts and tools on GPS signal replay (GPS重放模拟)
2014-05-28 一些关于GPS重放模拟的努力以及小工具脚本
2010-10-02 关于清华留美学生高杏欣破解北斗扩频码事件(About Gao Xingxin crack compass codes)
2010-10-01 北斗卫星导航系统介绍(Introduction of Beidou/Compass China Satellite Navigation System)
ads-b
2015-07-11 使用单HACKRF板接收ADS-B信息并通过BTLE发至手机
2015-07-11 ADS-B BTLE air relay via single HACKRF TDD
2014-05-29 使用HACKRF巡视钓鱼岛(HACKRF ADS-B out)
2014-05-29 ADS-B out by HACKRF and received over the air by rtl-sdr dongle and dump1090
2013-08-07 rtl-sdr-rtl2832电视棒跟踪飞机-更简单的方法在Windows和Linux下(simpler way to track plane by rtl-sdr)
2012-12-27 rtl-sdr-rtl2832电视棒跟踪飞机step-by-step教程(tutorial ADS-B aircraft tracking by rtl-sdr rtl2832 gr-air-modes)
2012-11-25 rtl-sdr-rtl2832电视棒跟踪飞机(ADS-B aircraft tracking by rtl-sdr rtl2832 gr-air-modes)
lte
2014-11-01 LTE-Cell-Scanner supports bladeRF now (LTE小区搜索程序新增bladeRF硬件支持)
2014-08-24 LTE Cell detected in Beijing China
2014-08-09 使用lameditor和asn1c开源工具解析北京LTE现网 RRC SIB ASN1消息
2014-07-07 How to decode LTE RRC/SIB/ASN1 messages by lameditor and asn1c
2014-06-21 Matlab看实时TD-LTE信号(Matlab小伙伴可大展身手了)(Matlab TCP interface to HACKRF rtl-sdr)
2014-06-02 OpenCL LTE-Cell-Scanner appears in rtl-sdr - OsmoSDR
2014-05-29 OpenCL acceleration is add to TDD FDD LTE-Cell-Scanner
2014-05-27 Whole 20MHz config LTE signal is decoded by HACKRF 19.2Msps with ASN1 SIB parsed
2014-05-26 完整20MHz带宽配置LTE信号被HACKRF-19.2M采样率成功解析
2014-04-12 使用C和C++直接调用HACKRF来支持LTE小区搜索(LTE Cell Scanner by HACKRF(C, C++))
2014-04-11 LTE小区搜索软件加入对HACKRF的支持，有望将来解调LTE SIB信息(Add hackrf support to LTE Cell Scanner)
2014-04-11 HACKRF support added to OpenCL TDD FDD LTE Cell Searcher Tracker
2014-03-29 OpenCL加速LTE小区搜索(rtl-sdr电视棒), 半秒扫一个频点(OpenCL accelerated LTE Cell Scanner)
2014-02-19 搞定LTE Scanner的TDD以及LNB模式,rtl-sdr电视棒扫描LTE MIB (rtl sdr LTE Cell Scanner)
2014-02-19 土法again LTE D频段(2500~2690MHz)三大运营商TD-LTE频谱全抓(TD-LTE Beijing capture scan)
2014-01-10 4G LTE(北京)信号捕捉(rtl-sdr 电视棒软件无线电)新扫到电信(LTE SDR Beijing)
btle
2024-05-13 The open-source BTLE (Bluetooth Low Energy) baseband chip design
2015-11-03 BTLE packet sniffer based on HACKRF (function and performance similar to TI's packet sniffer)
2014-08-05 HACKRF BladeRF BTLE BT4.0 无线发包器(iBeacon, Link setup, etc.)
2014-08-05 A BTLE (Bluetooth Low energy) BT4.0 radio packet sender (BladeRF, HACKRF)
hw-sw-fw
2022-12-31 想DIY软件无线电？只看这一篇就足够了：SDR硬件方案一网打尽
2016-08-20 知乎首答-我对手机射频软件的理解
2015-09-02 给hackrf加上1602LCD以及UART(附带固件编译方法)
2015-09-01 Add UART and 1602LCD to HACKRF and build firmware
2015-02-24 Notes on DFU mode and firmware of hackrf
2014-12-15 Notes on STM32 based BPF (update frequently)
2014-11-02 test rtlsdr hackRF and bladeRF in VMware virtual machine (虚拟机内使用软件无线电)
2014-08-27 bladeRF 固件与 FPGA 注记
misc
2026-05-04 My PhD Thesis PABT Pilot Assisted Block Transmission
2023-09-16 卖掉了！（原贴：记录一下比利时根特买二手BMW-318d）
2021-08-15 Optimization too early (过早优化）
2020-01-02 飞行日记6及以后连载在知乎专栏
2017-12-27 飞行日记5
2017-12-02 飞行日记4
2017-10-28 飞行日记3
2017-09-23 飞行日记2
2017-05-07 飞行日记
2017-03-21 PhD/Researcher position on hardware/software co-design of flexible modular radio network platforms
2016-10-11 测试sdr-x.github.io的RSS feed功能
2016-10-09 记录一下比利时根特买二手BMW-318d
2016-06-27 比利时折腾网络记(兼亚马逊血泪教训)
wifi
2024-05-25 Wi-Fi beamforming explained 3 beam direction control for Uniform Linear Array (ULA)
2024-05-25 Wi-Fi beamforming explained 2 double-slit experiment
2024-05-25 Wi-Fi beamforming explained 1 from single antenna to 2 antennas
2020-01-02 开源Wi-Fi芯片/FPGA设计以及背后的中国开发者
2016-08-20 SIFS (short inter frame spacing) is the shortest or longest time required by WIFI standard for sending ACK back to originator?
starlink
2026-07-15 Starlink Analysis – Supplement(11):Multiple Access, Duplexing, Beams, Gateway Stations, Phased-Array Interfaces, Subcarriers, Channel Model, and Random Access
2026-07-14 Starlink Analysis – Supplement(10):Discussion of Modems, RF Links, Beams, and Capacity
2026-07-12 Starlink Analysis – Supplement(9):Spectral Efficiency and Satellite Capacity
2026-07-12 Starlink Analysis – Supplement(8):Confirmation of Unique Word (UW) Usage
2026-07-11 Starlink Analysis – Supplement(7):Modulation, Coding, and Bit-Level Processing
2026-07-10 Starlink Analysis – Supplement(6):The Effect of Relativity on OFDM Clock Errors in LEO Communications
2026-07-08 Starlink Analysis – Supplement(5):Pilot Design for LEO Broadband Access Compared with Wi-Fi and Cellular Systems
2026-07-07 Starlink Analysis – Supplement (4):Frame Structure
2026-07-07 Starlink Analysis – Supplement (3):UW Selection, Sampling Rate, Bandwidth, and Configurable Parameters
2026-07-06 Starlink Analysis – Supplement (2): A Hypothesis on the Unique Word (UW)
2026-07-05 Starlink Analysis – Supplement (1): A Unique Modem Design Philosophy
2026-06-24 Starlink uplink signal analysis (6): Discovery of the Pilot Sub-Bands in Patents, and Signal Analysis Techniques for Time-Domain Structure and Modulation Symbols
2026-06-23 Starlink uplink signal analysis (5): Detailed Modulation Structures and Repeated Bit Sequences
2026-06-20 Starlink uplink signal analysis (4): OFDMA and RU allocation
2026-06-13 Starlink uplink signal analysis (3): demodulation is successful