I/Q Data for Dummies. This is a description of using I/Q Data representing a signal.
Since the topic may be quite confusing, I've described the same thing here from different point of views. If you find the information somewhat redundant, it is because it is. Different views may appeal to different readers, and if something seems unclear, keep on reading and it may be more comprehensible later - hopefully. Why I/Q Data? I/Q Data is a signal representation much more precise than just using a series of samples of the momentary amplitude of the signal. GSM - have we overslept the last wake-up call? - gsm.pdf.
The big GSM write-up – how to capture, analyze and crack GSM? – 1. So.
I had some requests asking me about how I did what I did with GSM. What tools did I use, what hardware and what options? Since I believe strongly that GSM needs to be “out in the hands of the people” meaning everybody should have access to cheap hardware and free, opensource software that helps understanding GSM in practice I thought I will create a series of write-ups describing the whole process from the beginning.
Enjoy! GSM (Global System for Mobile communication) was introduced as a standard in 1991. Later many people contributed to this theory essentially making GSM theoretically broken since 2003, but practical tools existed only for governmental organizations and mobile operators for such high prices nobody from the hacker community could buy them (not mentioning none of the manufacturers would have given him/her anything). So, the landscape of GSM hacking consists of two hardware options: USRP or OsmocomBB. Steps to crack GSM (originally outlined by Karsten Nohl):
Tutorial: Analyzing GSM with Airprobe and Wireshark. The RTL-SDR software defined radio can be used to analyze cellular phone GSM signals, using Linux based tools Airprobe and Wireshark.
This tutorial shows how I set up these tools for use with the RTL-SDR. Example – Analysing GSM with RTL-SDR Software Defined Radio Here is a screenshot and video showing an example of the type of data you can receive. You can see the unencrypted GSM packet information. You will not be able to see any sensitive information like voice or text message data since that part is encrypted. First, you will need to find out at what frequencies you have GSM signals in your area. Audio Player. The big GSM write-up – how to capture, analyze and crack GSM? – 4. So.
I had some requests asking me about how I did what I did with GSM. What tools did I use, what hardware and what options? Since I believe strongly that GSM needs to be “out in the hands of the people†meaning everybody should have access to cheap hardware and free, opensource software that helps understanding GSM in practice I thought I will create a series of write-ups describing the whole process from the beginning. Enjoy! Â. Receiving, Decoding and Decrypting GSM Signals with the RTL-SDR. Beginner Antennas. Antenna size depends on the frequency you want to hear: higher frequency (bigger number) - smaller antenna.
You need an antenna that receives signals from all directions - called omnidirectional.Materials make no difference: any type of wire is good, as long as it keeps its shape. Metal coat hangers are popular, multi-stranded or solid makes no difference. I'm a fan of No 10 house grounding wire. You need to connect your antenna to your RTL stick: coax cable is needed, read my hardware guide for details. Recommended beginner antenna.
Passive RADAR With a Dual Coherent Channel RTL-SDR. Juha Vierinen from the Kilpisjarvi Atmospheric Imaging Receiver Array has been working on a Dual Coherent Channel RTL-SDR modification.
This modification essentially involves using the same clock source for two RTL-SDR dongles, which can be done by desoldering and removing the clock on one dongle, and then using a cable to connect the clock from another dongle to the clock input of the desoldered dongle. Juha then was able to use his new dual coherent channel RTL-SDR to create a passive RADAR system. To do this, he connected the two RTL-SDRs to two log periodic Yagi antennas. From this setup he was able to detect airplanes and meteor echoes. An image cap and video showing RADAR detections over time is shown below. Longer rtlsdr fm radio passive radar video. Rtl_udp: Fork of rtl_fm with UDP controls. RTL-SDR FM radio receiver with GNU Radio Companion. Software Defined Radios. Software Defined Radios (SDRs) are the most innovative type of shortwave radios on the market today. As the name implies, these radios are actually a hardware accessory you attach to your personal computer. Most have multi-platform controllers and give you performance and flexibility you simply can’t get out of a comparably priced portable or tabletop radio.
The following list also contains radios that are PC controlled. Though they look similar to an SDR, PC controlled radios are simply radios that rely on a personal computer for the user interface and some performance enhancements. Below, you will find a list of all SDRs and PC controlled radios categorized by manufacturer. HDSDR Autocorrelation Mode - g4zfqradio. This page is intended as a guide.
It is a collection of notes and links so users may learn more. Autocorrelation is a specialised feature that analyses the content of a signal. Radio Signal Identification Guide. A guide to help you identify some amateur and utility digital radio signals and sounds which you may find on the frequency spectrum.
I will be slowly adding more to this list over time. If you enable stereo mix and pass the sample audio to an appropriate decoding program the sample audio should be decodable for most samples. If you would like to suggest a modification or contribute a sample, please send a sample, waterfall image and information about the signal to rtlsdrblog@gmail.com, or post in the comments. More sites with sample audio can be found at this list on dxzone.com. A very nice overview video of the HF spectrum by balint can be found here. RTL2832U Guidance - drm. Pictures from weather satellites with a USB TV tuner. Digital Radio Astronomy. Embrtlsdr. Rtl-sdr – OsmoSDR. DVB-T dongles based on the Realtek RTL2832U can be used as a cheap SDR, since the chip allows transferring the raw I/Q samples to the host, which is officially used for DAB/DAB+/FM demodulation. The possibility of this has been discovered by Eric Fry (History and Discovery of RTLSDR). Software Defined Radio for Mariners: Reducing electrical noise.
- You can use alu foil, but make sure it touches the metal part of the USB plug. - Remove the metal support from the USB extension cable on the end where you connect the RTL stick.
This will eliminate noise picked up by the USB extension cable. - If you have a spare car battery, connect the metal part of USB plug to the negative terminal. - Mobile operation or no car battery? Wrap the center conductor of coax around the metal part of the USB plug, then place the stick in the middle of coiled coax. Testing setup Your antenna receives noise and signal. Without an antenna any signal received is by the RTL stick and the cables, and you do not want that.For this test: Nooelec RTL-SDR 820T stick, max gain, no antenna. Results Direct vs USB cable connection: USB cable (76cm) increased noise by 13 dB.USB plug metal connected to 1m coax: coax cable center conductor connected to the metal support of the USB plug.
Ham It Up vs SDR UP 100. The Ham-It-Up and the Up 100 are the two cheapest shortwave adapters available: direct competitors at 50 USD (including shipping).
For this review, I purchased the Ham-It-Up and received the Up-100 for free for testing. Shipping and customer service The Ham-It-Up comes from the States with tracked shipping; you get emails where it is, but when the package leaves the US no more tracking info available. You can buy on Ebay, Amazon or via the manufacturer's website.The Up-100 ships from Croatia (that's a country in Europe next to Italy) with no tracking. Software Defined Radio for Mariners: Ham It Up vs SDR UP 100. Software Defined Radio for Mariners: Beginner Antennas. Rtl-sdr.com - A blog about RTL-SDR (RTL2832) and cheap software defined radio. ELAD Receptor SDR FDM-S1 en Astro Radio S.L. Index of /fredkrom/IQData. RTL SDR. New Linux/GNURadio users, read this before installing! : RTLSDR. GNU Radio - WikiStart - gnuradio.org. Introduction¶ GNU Radio is a free & open-source software development toolkit that provides signal processing blocks to implement software radios.
It can be used with readily-available low-cost external RF hardware to create software-defined radios, or without hardware in a simulation-like environment. It is widely used in hobbyist, academic and commercial environments to support both wireless communications research and real-world radio systems. GNU Radio is licensed under the GNU General Public License (GPL) version 3 or later. GNU Radio - WikiStart - gnuradio.org. New Linux/GNURadio users, read this before installing! : RTLSDR.