Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [software-defined-radio]

Radio devices that use digital signal processing in place of analog electronic components to manipulate RF signals.

306 questions
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SDR sampling bandwidth - do the bits per sample matter?

I'm looking at data converter chips for a homebrew SDR design, and I see that I can choose not just the sampling frequency, but also the bits per sample. Obviously the sampling frequency has to be several times the target frequency, but what effect…
Adam Davis
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SDR: Quadrature demodulation vs direct RF sampling

I see that many SDRs use a quadrature demodulator and sample I and Q signals. But is it possible to downconvert the RF signal instead, sample it with only one ADC, and get the same capabilities of digital postprocessing? So if we want to observe…
BarsMonster - R2AYN
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Is is possible to operate D-Star from a software-defined radio?

What is preventing a software-defined radio from transmitting the D-Star protocol?
Paul V
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How do I receive ATV with GNU Radio?

How do I receive Amateur television (ATV) — e.g., NTSC in the U.S. — with GNU Radio so I can play the A/V in, e.g., the VLC video player? Are there any example GNU Radio block diagrams to accomplish such a task? cf. this for an example on how to…
Geremia
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Can an amateur use cellular technologies with SDR?

Software Defined Radio is opening up many new possibilities for amateur digital modes. One family of technologies that interests me is cellular. 2G GSM voice/sms and 2.5G GPRS data has been proven to work with OpenBTS on a USRP SDR using licensed…
JC Hulce
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Why is dynamic range relevant for an SDR?

Sometimes I see dynamic range mentioned as a figure of merit for an SDR. For example, I know that the bits per sample used by the analog to digital converter can affect the dynamic range. Why do I care about dynamic range? What happens when I don't…
Phil Frost - W8II
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Multiple simultaneous tunings with SDR

I just found out about WebSDR, and I was wondering how is it possible that many listeners listen and tune to different stations simultaneously. Which components/technologies allow this, and how does this roughly work?
Cobe
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Confusion about SDR

I've just written code for the RTL2832 to receive and decode ADS-B packets (very cool!). I had some confusion about what is actually happening: Is the raw data coming from the USB dongle literally samples of the ~1090 MHz wave? Or is the carrier…
Nathan Wong
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10
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Which qualities/features does an SDR radio device need to be usable for Amateur Radio?

I know what things to note when selecting an analog amateur radio, but SDR devices have completely different specs, e.g. sample rate and resolution. What do I need to know about the device to make sure it is suitable for working Amateur Radio…
jkj
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Getting Started with Digital Modes on VHF on Linux

I am interested in learning about digital modes using 2m and Linux. I have a couple of older 2m rigs (HTX-212 and an old Yaesu) with no additional hardware, like a TNC. What current resources exist for hardware setup and software configuration for…
Rob Gibson
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Remote SDR on the internet other than WebSDR?

Besides WebSDR, what remote Software-Defined-Radio stations (for shortwave or amateur bands) might be available for open public access over the internet? What protocols do these SDR stations use to stream data over the internet? Do any of these…
hotpaw2
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Why are commercial SDRs so limited in operating frequency?

I spent a bit of time researching SDRs, mostly looking into the possibility of building an all-FPGA-based TRX. There are a lot of commercial ready solutions; some are cheap, some not, but they all tend to be operating from 50/70 MHz frequency…
Ulterior
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AIS and RTL-SDR Dongles

I am looking for an Windows-based AIS Decoder for RTL Dongles. Currently, there is a solution available using GNU Radio and SDR# but it is complicated to set up and keep running. ADSB has a dedicated solution called RTL1090 that connects directly to…
Mark Cupitt
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Is there a name for the demodulation technique described here using the parallax propeller?

Is this a recognized SDR technique with a name, or is just a combination of DSP, r/f techniques ? I asked the author, but didn't receive an answer, perhaps because he thought it was "obvious" (not to me, though, an SDR / electronics…
mstram
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Would it be possible for a software-defined FM receiver to demodulate two signals on the same frequency?

When two FM signals are transmitted on the same (or about the same) center frequency, either you hear only one or you hear that noise I'm sure most of you have heard. Would it be possible for a software-defined receiver to track both signals and…
Someone
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