Software Defined Radio (SDR) 101(Originally published on Monday, June 8, 2020)

 

Software Defined Radio (SDR) 101.

What is an SDR?

A Software-Defined Radio(SDR), is a radio environment that has all the front end devices(amplifiers, mixers, IQ units, CPLD, mod/demod equipment) in hardware and the operation of all these equipment including but not limited to signals processing is done using software.

 How is it useful?

Consider this scenario you are behind lines somewhere in a godforsaken land, and you need to have a very re-programmable front end and flexible signals processing software that can be swapped at will. Et Voila enter SDR, change the software, and modify the front end code you got real-time signals intelligence on the field.

 Apart from that in the civvie world, it's used for the analysis of radio signals be it sub-1-GHz systems and analysis and security assessment of wireless systems.

 Some SDR.

RTL-SDR, cheap effective for understanding stuff regarding SDR and it's accompanying software which is mostly GnuRadio Companion(GRC), LabVIEW, or MATLAB. So, this thing can only receive and not transmit (ugh, where's the fun in that).

 Then comes HackRF, decent/half-decent hardware goes up to 6GHz and can do half-duplex, i.e either transmit or receive well the problem is no feedback no Bueno.

 

Then comes that pricey stuff, oh boy, this really does put a smile on my face. USRP various versions I wish I owned one of these the kind telemetry experiments that I would with them.

 

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