Re: Packet encoder and decoder blocks not available in the GNU radio 3.8
I think in 3.8 Barry handled these as stream instead of text file. So if I was you I’d handle it as stream or have a break and interrupt and send the data manually myself with a combination of message strobe and qt message. On Tue, 24 Jan 2023 at 19:08, Komal Kumar wrote: > Hello. > I have implemented simple qpsk modulation and demodulation (text file data > transmission) using the GNu radio 3.7 . I have no problem with the GNu > radio 3.7 > I am using a raspberry pi 4B with the Pluto SDR . The raspberry pi 4 > default is GNU radio 3.8, > I didn't find any Packet encoder and decoder blocks in GNU radio 3.8 . > I am unable to find the alternatives also. > Can anyone give the flowgraph to implement the text file transmission > using the QPSK modulation and demodulation in gnu radio 3.8 or any > procedure to complete my application(transmitting text file data using QPSK > without packet encoder and packet decoder). > > > Thank You. > >
Re: How to display a part of the GRC spectrum?
On 03/02/2023 12:44, George Edwards wrote: Hi Marcus, I do not have any hardware. I am doing everything in simulation. I designed the grc to translate a QPSK modulated signal to a rf freq of 1GHz at a sample rate of 3GHz. Running this signal into QT freq sink or a webgui freq sink shows the upconverted modulated signal at 1GHz, with a support base that is miniscule over such a wide freq range +/- 1.5 GHz. So I would like to know if there is a way to instruct either GUI's such that the display pops up over a range of 1G +/- 2 MHz or a range of my choosing at the sample rate I am working at? Thank you! George If it's just in simulation, I guess I don't understand why you need to "simulate" such high sample rates if your signal is only fairly narrow. It is usually the case that for actual hardware, signals are delivered as a complex baseband at whatever your sample rate is. You might need to shift stuff around a bit sometimes, which is where the frequency-xlating filters and friends come into play. In simulation, you almost never need to simulate the actual radio hardware *at its operating frequencies and bandwidths*. In fact, doing that in Gnu Radio *in real time* would be extremely challenging on ordinary computers the frequencies you've quoted. When folks talk about Gnu Radio as a "useful simulation tool", they're mostly talking about simulating DSP processing chains *at the rates typically seen in complex baseband delivered by hardware*, and NOT necessarily about it being a tool that is useful to simulate actual hardware -- at least, not in real time. On Fri, Feb 3, 2023, 9:38 AM Marcus D. Leech wrote: On 03/02/2023 11:30, George Edwards wrote: Hi Fabian, Thanks for your suggestion! However, it will not help me because I would like to see the spectrum displayed over the proper range 1GHz +/- 4MHz. George I think we now need more information about your setup. What type of hardware? I know of no hardware that can deliver samples at 3Gsps into a host computer that is also compatible with Gnu Radio. Processing samples at 3Gsps in an ordinary computer even with blazing-edge current CPU tech is a "significant challenge", and you sure as heck aren't going to do it in Gnu Radio. My *suspicion* is that you're confused about the difference between the *desired center frequency*, bandwidth, and corresponding sample rate. On Fri, Feb 3, 2023, 9:06 AM Fabian Schwartau wrote: Hi George, I don't know if the Frequency sink can do that for you, but I guess it cannot. One way is to mix the signal with a complex oscillation and a multiplier with the oscillator running at the negative frequency you wish to downshift the signal. Then low-pass filter and downsample the signal. You can then feed that into the Frequency sink and also set you oscillator frequency as offset frequency in the sink's settings. Best, Fabian Am 03.02.23 um 16:52 schrieb George Edwards: > Dear GNURadio Community, > > Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz > and wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, > how do I get the QT GUI Frequency sink to plot over this range? > > Thank you! > > George
Re: How to display a part of the GRC spectrum?
Thank you all for your wonderful ideas! Regards, George On Fri, Feb 3, 2023, 10:22 AM Marcus D. Leech wrote: > On 03/02/2023 12:07, George Edwards wrote: > > Thank you Marcus, thank you everyone! > > A more fundamental question I have is: Let's assume I was working at a low > sample rate, say 32 kHz. Both the QT Freq GUI and the webgui would display > a spectrum between -16 kHz +16 kHz. Suppose, I would like the displays to > pop-up over the range 5-12 kHz, is there a way to instruct either the QT or > webgui block to plot what I consider my range of interest at a sample rate > of 32 kHz? > > Thanks for all your inputs. > > Regards, > George > > Yeah, you can just use the UI controls to "zoom in" if that's all you care > about. > > If you want it (the GUI block) to be only "seeing" that spectrum, then the > frequency-xlating FIR/FFT filter does what you want. > > > > On Fri, Feb 3, 2023, 9:12 AM Marcus Müller wrote: > >> First of all, that's a high sampling rate! >> >> You would want to shift the signal (e.g using the "Rotator" block, or >> just by using a signal source at the shift frequency and a (conjugate) >> multiplication), then decimate it by a factor of 3 GHz / 8 MHz = 375. >> >> From a point of view of designing the decimator, decimation by 375 is >> quite a mouthful - it requires a filter transition width of >> significantly less than 1/375 of the input Nyquist rate. So, it would >> seem advisable to do this decimation in a cascade of decimators – in the >> extreme case, decimation by 3, by 5, by 5, by 5. >> >> Best regards, >> Marcus >> >> On 2/3/23 16:52, George Edwards wrote: >> > Dear GNURadio Community, >> > >> > Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz >> > and wish to display the spectrum over the fixed range of 1GHz +/- >> > 4MHz, how do I get the QT GUI Frequency sink to plot over this range? >> > >> > Thank you! >> > >> > George >> >> >
Re: How to display a part of the GRC spectrum?
Hi Marcus, I do not have any hardware. I am doing everything in simulation. I designed the grc to translate a QPSK modulated signal to a rf freq of 1GHz at a sample rate of 3GHz. Running this signal into QT freq sink or a webgui freq sink shows the upconverted modulated signal at 1GHz, with a support base that is miniscule over such a wide freq range +/- 1.5 GHz. So I would like to know if there is a way to instruct either GUI's such that the display pops up over a range of 1G +/- 2 MHz or a range of my choosing at the sample rate I am working at? Thank you! George On Fri, Feb 3, 2023, 9:38 AM Marcus D. Leech wrote: > On 03/02/2023 11:30, George Edwards wrote: > > Hi Fabian, > Thanks for your suggestion! > > However, it will not help me because I would like to see the spectrum > displayed over the proper range 1GHz +/- 4MHz. > > George > > I think we now need more information about your setup. What type of > hardware?I know of no hardware that can deliver > samples at 3Gsps into a host computer that is also compatible with Gnu > Radio. > > Processing samples at 3Gsps in an ordinary computer even with blazing-edge > current CPU tech is a "significant challenge", > and you sure as heck aren't going to do it in Gnu Radio. > > My *suspicion* is that you're confused about the difference between the > *desired center frequency*, bandwidth, and corresponding > sample rate. > > > On Fri, Feb 3, 2023, 9:06 AM Fabian Schwartau wrote: > >> Hi George, >> >> I don't know if the Frequency sink can do that for you, but I guess it >> cannot. >> One way is to mix the signal with a complex oscillation and a multiplier >> with the oscillator running at the negative frequency you wish to >> downshift the signal. Then low-pass filter and downsample the signal. >> You can then feed that into the Frequency sink and also set you >> oscillator frequency as offset frequency in the sink's settings. >> >> Best, >> Fabian >> >> Am 03.02.23 um 16:52 schrieb George Edwards: >> > Dear GNURadio Community, >> > >> > Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz >> > and wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, >> > how do I get the QT GUI Frequency sink to plot over this range? >> > >> > Thank you! >> > >> > George >> >> >> >
Re: How to display a part of the GRC spectrum?
On 03/02/2023 12:07, George Edwards wrote: Thank you Marcus, thank you everyone! A more fundamental question I have is: Let's assume I was working at a low sample rate, say 32 kHz. Both the QT Freq GUI and the webgui would display a spectrum between -16 kHz +16 kHz. Suppose, I would like the displays to pop-up over the range 5-12 kHz, is there a way to instruct either the QT or webgui block to plot what I consider my range of interest at a sample rate of 32 kHz? Thanks for all your inputs. Regards, George Yeah, you can just use the UI controls to "zoom in" if that's all you care about. If you want it (the GUI block) to be only "seeing" that spectrum, then the frequency-xlating FIR/FFT filter does what you want. On Fri, Feb 3, 2023, 9:12 AM Marcus Müller wrote: First of all, that's a high sampling rate! You would want to shift the signal (e.g using the "Rotator" block, or just by using a signal source at the shift frequency and a (conjugate) multiplication), then decimate it by a factor of 3 GHz / 8 MHz = 375. From a point of view of designing the decimator, decimation by 375 is quite a mouthful - it requires a filter transition width of significantly less than 1/375 of the input Nyquist rate. So, it would seem advisable to do this decimation in a cascade of decimators – in the extreme case, decimation by 3, by 5, by 5, by 5. Best regards, Marcus On 2/3/23 16:52, George Edwards wrote: > Dear GNURadio Community, > > Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz > and wish to display the spectrum over the fixed range of 1GHz +/- > 4MHz, how do I get the QT GUI Frequency sink to plot over this range? > > Thank you! > > George
Re: How to display a part of the GRC spectrum?
Thank you Marcus, thank you everyone! A more fundamental question I have is: Let's assume I was working at a low sample rate, say 32 kHz. Both the QT Freq GUI and the webgui would display a spectrum between -16 kHz +16 kHz. Suppose, I would like the displays to pop-up over the range 5-12 kHz, is there a way to instruct either the QT or webgui block to plot what I consider my range of interest at a sample rate of 32 kHz? Thanks for all your inputs. Regards, George On Fri, Feb 3, 2023, 9:12 AM Marcus Müller wrote: > First of all, that's a high sampling rate! > > You would want to shift the signal (e.g using the "Rotator" block, or > just by using a signal source at the shift frequency and a (conjugate) > multiplication), then decimate it by a factor of 3 GHz / 8 MHz = 375. > > From a point of view of designing the decimator, decimation by 375 is > quite a mouthful - it requires a filter transition width of > significantly less than 1/375 of the input Nyquist rate. So, it would > seem advisable to do this decimation in a cascade of decimators – in the > extreme case, decimation by 3, by 5, by 5, by 5. > > Best regards, > Marcus > > On 2/3/23 16:52, George Edwards wrote: > > Dear GNURadio Community, > > > > Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz > > and wish to display the spectrum over the fixed range of 1GHz +/- > > 4MHz, how do I get the QT GUI Frequency sink to plot over this range? > > > > Thank you! > > > > George > >
Re: How to display a part of the GRC spectrum?
On 03/02/2023 11:30, George Edwards wrote: Hi Fabian, Thanks for your suggestion! However, it will not help me because I would like to see the spectrum displayed over the proper range 1GHz +/- 4MHz. George I think we now need more information about your setup. What type of hardware? I know of no hardware that can deliver samples at 3Gsps into a host computer that is also compatible with Gnu Radio. Processing samples at 3Gsps in an ordinary computer even with blazing-edge current CPU tech is a "significant challenge", and you sure as heck aren't going to do it in Gnu Radio. My *suspicion* is that you're confused about the difference between the *desired center frequency*, bandwidth, and corresponding sample rate. On Fri, Feb 3, 2023, 9:06 AM Fabian Schwartau wrote: Hi George, I don't know if the Frequency sink can do that for you, but I guess it cannot. One way is to mix the signal with a complex oscillation and a multiplier with the oscillator running at the negative frequency you wish to downshift the signal. Then low-pass filter and downsample the signal. You can then feed that into the Frequency sink and also set you oscillator frequency as offset frequency in the sink's settings. Best, Fabian Am 03.02.23 um 16:52 schrieb George Edwards: > Dear GNURadio Community, > > Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz > and wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, > how do I get the QT GUI Frequency sink to plot over this range? > > Thank you! > > George
Re: How to display a part of the GRC spectrum?
Hi Fabian, Thanks for your suggestion! However, it will not help me because I would like to see the spectrum displayed over the proper range 1GHz +/- 4MHz. George On Fri, Feb 3, 2023, 9:06 AM Fabian Schwartau wrote: > Hi George, > > I don't know if the Frequency sink can do that for you, but I guess it > cannot. > One way is to mix the signal with a complex oscillation and a multiplier > with the oscillator running at the negative frequency you wish to > downshift the signal. Then low-pass filter and downsample the signal. > You can then feed that into the Frequency sink and also set you > oscillator frequency as offset frequency in the sink's settings. > > Best, > Fabian > > Am 03.02.23 um 16:52 schrieb George Edwards: > > Dear GNURadio Community, > > > > Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz > > and wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, > > how do I get the QT GUI Frequency sink to plot over this range? > > > > Thank you! > > > > George > > >
Re: How to display a part of the GRC spectrum?
Am 03.02.23 um 17:08 schrieb Marcus D. Leech: On 03/02/2023 11:04, Fabian Schwartau wrote: Hi George, I don't know if the Frequency sink can do that for you, but I guess it cannot. One way is to mix the signal with a complex oscillation and a multiplier with the oscillator running at the negative frequency you wish to downshift the signal. Then low-pass filter and downsample the signal. You can then feed that into the Frequency sink and also set you oscillator frequency as offset frequency in the sink's settings. Best, Fabian That's pretty-much what the frequency-xlating FIR filter/FFT filter block is for... Nice to know... Also, sampling at 3GHz? Into an ordinary computer? Really? Maybe he is just simulating stuff... Am 03.02.23 um 16:52 schrieb George Edwards: Dear GNURadio Community, Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz and wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, how do I get the QT GUI Frequency sink to plot over this range? Thank you! George
Re: How to display a part of the GRC spectrum?
First of all, that's a high sampling rate! You would want to shift the signal (e.g using the "Rotator" block, or just by using a signal source at the shift frequency and a (conjugate) multiplication), then decimate it by a factor of 3 GHz / 8 MHz = 375. From a point of view of designing the decimator, decimation by 375 is quite a mouthful - it requires a filter transition width of significantly less than 1/375 of the input Nyquist rate. So, it would seem advisable to do this decimation in a cascade of decimators – in the extreme case, decimation by 3, by 5, by 5, by 5. Best regards, Marcus On 2/3/23 16:52, George Edwards wrote: Dear GNURadio Community, Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz and wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, how do I get the QT GUI Frequency sink to plot over this range? Thank you! George
Re: How to display a part of the GRC spectrum?
Hi George and Marcus, Yes I agree with Marcus, the Frequency Xlating FIR filter works surprisingly well. https://wiki.gnuradio.org/index.php?title=Frequency_Xlating_FIR_Filter I’ve run some tests with placing (Simulating) audio tones at high frequencies ie 1MHz + 880 Hz and the tone is perfectly preserved at 880 Hz after XLating. Glen > On Feb 3, 2023, at 11:08 AM, Marcus D. Leech wrote: > > On 03/02/2023 11:04, Fabian Schwartau wrote: >> Hi George, >> >> I don't know if the Frequency sink can do that for you, but I guess it >> cannot. >> One way is to mix the signal with a complex oscillation and a multiplier >> with the oscillator running at the negative frequency you wish to downshift >> the signal. Then low-pass filter and downsample the signal. You can then >> feed that into the Frequency sink and also set you oscillator frequency as >> offset frequency in the sink's settings. >> >> Best, >> Fabian > That's pretty-much what the frequency-xlating FIR filter/FFT filter block is > for... > > Also, sampling at 3GHz? Into an ordinary computer? Really? > > >> >> Am 03.02.23 um 16:52 schrieb George Edwards: >>> Dear GNURadio Community, >>> >>> Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz and >>> wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, how do >>> I get the QT GUI Frequency sink to plot over this range? >>> >>> Thank you! >>> >>> George >> >> > >
Re: How to display a part of the GRC spectrum?
On 03/02/2023 11:04, Fabian Schwartau wrote: Hi George, I don't know if the Frequency sink can do that for you, but I guess it cannot. One way is to mix the signal with a complex oscillation and a multiplier with the oscillator running at the negative frequency you wish to downshift the signal. Then low-pass filter and downsample the signal. You can then feed that into the Frequency sink and also set you oscillator frequency as offset frequency in the sink's settings. Best, Fabian That's pretty-much what the frequency-xlating FIR filter/FFT filter block is for... Also, sampling at 3GHz? Into an ordinary computer? Really? Am 03.02.23 um 16:52 schrieb George Edwards: Dear GNURadio Community, Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz and wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, how do I get the QT GUI Frequency sink to plot over this range? Thank you! George
Re: How to display a part of the GRC spectrum?
Hi George, I don't know if the Frequency sink can do that for you, but I guess it cannot. One way is to mix the signal with a complex oscillation and a multiplier with the oscillator running at the negative frequency you wish to downshift the signal. Then low-pass filter and downsample the signal. You can then feed that into the Frequency sink and also set you oscillator frequency as offset frequency in the sink's settings. Best, Fabian Am 03.02.23 um 16:52 schrieb George Edwards: Dear GNURadio Community, Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz and wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, how do I get the QT GUI Frequency sink to plot over this range? Thank you! George
Re: Grc_gnuradio import blks2 replacement?
Not in general, but most functionality inside was either supplied by GNU Radio itself or is part of a different module. It depends! On 2/1/23 19:03, George Edwards wrote: Porting an older version of some code that used an earlier version of gnuradio libs, and am rebuilding with gnuradio 3.10. Old code referred to an import of blks2 from grc_gnuradio which then fails with No module named grc_radio. Is there a replacement for that module?
How to display a part of the GRC spectrum?
Dear GNURadio Community, Let's say I build a GRC flowgraph operating at a sample rate of 3 GHz and wish to display the spectrum over the fixed range of 1GHz +/- 4MHz, how do I get the QT GUI Frequency sink to plot over this range? Thank you! George
Sampling rates
Our bse band signals are less than 40kH. They are sent over incredibly noisy skywaves. I want all my samples taken at 8 Mz with 6 bit accuracy for a long pipeline of 32 bit processors. I have the dynamic range matched to cost, Moore's Law and flexibility. All my DSP is working a 4Mhz bandwidth. Give me an accurate multiplier on the input to down convert to the 8MH range. Everything simplifies, we are all focused on a dsp with the sme bandwidth, resolution and dynamic range. The codes never change when we swp frequencies. All your work speeds up.
