Live data from Hacker News

Intro to SDR and RF Signal Analysis

elttam.com.au

11–20 of 43 posts

Re: Intro to SDR and RF Signal Analysis

#12

For anyone interested in Software-defined radio (SDR) I can also highly recommend the Cyberspectrum YouTube channel [1]. [1] https://www.youtube.com/playlist?list=PLPmwwVknVIiXGzKhtimTM...

There is also meetup groups in San Francisco [1] and Melbourne (Australia) [2]. [1] https://www.meetup.com/en-US/Cyberspectrum/ [2] https://www.meetup.com/en-US/Cyberspectrum-Melbourne/

Thanks for posting links to the videos and the meetup group, would've joined it years ago if I'd known about it. Quick question, anything radar related in the videos?

Re: Intro to SDR and RF Signal Analysis

#14
post #9

Earlier quoted context omitted.

If you have an Android phone, grab a NFC reader app - this should at least tell you if the card is able to be cloned.

Not all RFID cards are created the same. Most RFID cards that are some kind of "smart" (i.e. contactless bank cards, subway tickets) conform to ISO/IEC 14443 standard that mandates the use of ~13.5MHz carrier to communicate between the reader and the card. This is "the NFC" as your phone understands it. Proximity cards used for door access usually have the 125kHz carrier compatible with the EM-Marin EM4100. No cell p…

Thanks.

Re: Intro to SDR and RF Signal Analysis

#15

Are there companies/sectors that look for candidates with these skills, or is this more focused towards hackers and hobbyists?

Virtually every professional radio is software defined to some extent these days, so every company that designs radios wants signal processing and information theory skills, more so if they are doing proprietary protocols rather than implementing a standard. It's pretty well the same skill set, whether you are designing or analysing systems. There is a surprising amount of reverse engineering in building radio systems, as the big players (looking at you Motorola) often drop speed humps into their implemetations to try and break compatability with the smaller players' products.

Re: Intro to SDR and RF Signal Analysis

#16

For anyone interested in Software-defined radio (SDR) I can also highly recommend the Cyberspectrum YouTube channel [1]. [1] https://www.youtube.com/playlist?list=PLPmwwVknVIiXGzKhtimTM...

Thanks for the links. I's also recommend http://www.desktopsdr.com/

It's a course that relies heavily on MATLAB though.

Re: Intro to SDR and RF Signal Analysis

#17
post #15

Are there companies/sectors that look for candidates with these skills, or is this more focused towards hackers and hobbyists?

Virtually every professional radio is software defined to some extent these days, so every company that designs radios wants signal processing and information theory skills, more so if they are doing proprietary protocols rather than implementing a standard. It's pretty well the same skill set, whether you are designing or analysing systems. There is a surprising amount of reverse engineering in building radio system…

Where can I read more about this?

It's always nice to see RF and Signal Processing stuff on HN.

Re: Intro to SDR and RF Signal Analysis

#18
post #9

Earlier quoted context omitted.

If you have an Android phone, grab a NFC reader app - this should at least tell you if the card is able to be cloned.

Not all RFID cards are created the same. Most RFID cards that are some kind of "smart" (i.e. contactless bank cards, subway tickets) conform to ISO/IEC 14443 standard that mandates the use of ~13.5MHz carrier to communicate between the reader and the card. This is "the NFC" as your phone understands it. Proximity cards used for door access usually have the 125kHz carrier compatible with the EM-Marin EM4100. No cell p…

Assuming you could read signals to/from a key-fob/HID-card, isn't there some encryption involved that would prevent merely repeating the signal to "clone" a key-fob?

Re: Intro to SDR and RF Signal Analysis

#20
post #9

Earlier quoted context omitted.

Not all RFID cards are created the same. Most RFID cards that are some kind of "smart" (i.e. contactless bank cards, subway tickets) conform to ISO/IEC 14443 standard that mandates the use of ~13.5MHz carrier to communicate between the reader and the card. This is "the NFC" as your phone understands it. Proximity cards used for door access usually have the 125kHz carrier compatible with the EM-Marin EM4100. No cell p…

Assuming you could read signals to/from a key-fob/HID-card, isn't there some encryption involved that would prevent merely repeating the signal to "clone" a key-fob?

You can't clone it as many do challenge response but you can relay it - check out NFCgate for example.

This would allow you to say, hold one device to the reader and one against someone's pocket to open a door.

Or to share an NFC transit pass between multiple people over the internet.

Post reply on HN