Re: Understanding Pulsed signal Demodulation and decimation in GNU Radio
Hi Isaac, I am not sure what you are trying to achive. However, your low pass filter seems to be set up incorrectly. You have a signal with 1MHz and 10MHz samplerate. Your low-pass filter has a cutoff at 5MHz and then down-samples by 100. If you want to make sure that there are no frequency components aliased during the downsampling step, you should have a cutoff of 100kHz or below. When you set the cutoff to 100k and the transition width to 50k, you get a nice constant rect at the output. Hope that helps. Best, Fabian Am 20.07.22 um 19:03 schrieb isaac mario tupac davila: Hello everyone My name is Isaac. I'm dealing with a curious behaviour that I can't understand... I'm generating my pulsed signal by multiplying a vector source and a signal source. Then I'm multiplying this pulsed signal with a continuous signal source at the same frequency, passing then for a low pass filter and seeing it in a time sink block. The result should be a set of rectangles with the same amplitude and period. The curious thing here is that the amplitude varies in time (from 0 to max amplitude and vice versa). Any idea why the amplitude varies in time? I attach the flowgraph just in case. Any idea or help will be appreciated. Thanks Isaac t.
Re: Understanding Pulsed signal Demodulation and decimation in GNU Radio
Hi Isaac, I am not sure what you are trying to achive. However, your low pass filter seems to be set up incorrectly. You have a signal with 1MHz and 10MHz samplerate. Your low-pass filter has a cutoff at 5MHz and then down-samples by 100. If you want to make sure that there are no frequency components aliased during the downsampling step, you should have a cutoff of 100kHz or below. When you set the cutoff to 100k and the transition width to 50k, you get a nice constant rect at the output. Hope that helps. Best, Fabian Am 20.07.22 um 19:03 schrieb isaac mario tupac davila: Hello everyone My name is Isaac. I'm dealing with a curious behaviour that I can't understand... I'm generating my pulsed signal by multiplying a vector source and a signal source. Then I'm multiplying this pulsed signal with a continuous signal source at the same frequency, passing then for a low pass filter and seeing it in a time sink block. The result should be a set of rectangles with the same amplitude and period. The curious thing here is that the amplitude varies in time (from 0 to max amplitude and vice versa). Any idea why the amplitude varies in time? I attach the flowgraph just in case. Any idea or help will be appreciated. Thanks Isaac t.
Re: Understanding Pulsed signal Demodulation and decimation in GNU Radio
Ohh... bandwidth is just half the sample rate of course. So the cutoff has to be 50k and transition 20k for example. Am 21.07.22 um 10:45 schrieb Fabian Schwartau: Hi Isaac, I am not sure what you are trying to achive. However, your low pass filter seems to be set up incorrectly. You have a signal with 1MHz and 10MHz samplerate. Your low-pass filter has a cutoff at 5MHz and then down-samples by 100. If you want to make sure that there are no frequency components aliased during the downsampling step, you should have a cutoff of 100kHz or below. When you set the cutoff to 100k and the transition width to 50k, you get a nice constant rect at the output. Hope that helps. Best, Fabian Am 20.07.22 um 19:03 schrieb isaac mario tupac davila: Hello everyone My name is Isaac. I'm dealing with a curious behaviour that I can't understand... I'm generating my pulsed signal by multiplying a vector source and a signal source. Then I'm multiplying this pulsed signal with a continuous signal source at the same frequency, passing then for a low pass filter and seeing it in a time sink block. The result should be a set of rectangles with the same amplitude and period. The curious thing here is that the amplitude varies in time (from 0 to max amplitude and vice versa). Any idea why the amplitude varies in time? I attach the flowgraph just in case. Any idea or help will be appreciated. Thanks Isaac t.
Re: Problems in my Python OOT specifications using input and output vectors
Hello GNURadio Community,
No need to respond to my posting, I figured it out.
Thank you!
George
On Wed, Jul 20, 2022 at 1:01 PM George Edwards
wrote:
> Hello GNURadio Community,
>
> I wrote a Python OOT block that takes a vector input and outputs a vector
> of the same size.
>
> In the grc, my OOT block is preceeded by a stream to vector and followed
> by a vector to stream (I specify the vector number items in both blocks
> as well as the yml for my Python OOT). My problem lies in the input/output
> specification that I am unable to figure out.
>
> First I specified the input/output profile as:
> in_sig = [np.float32*vectlen],
> out_sig = [np.float32*vectlen])
> The OOT compiled, but when I ran the grc, it showed that the * breaks the
> code.
> Next I tried:
> in_sig = [(np.float32, vectlen)],
> out_sig = [(np.float32, vectlen)])
> The grc plot for the output came up, but did not work. So I put in some
> print statements in the work() function after the following lines:
> in0 = input_items[0]
> out = output_items[0]
> print("length of input data: {}".format(len(in0))
> for i in range (0, vectlen):
> print(" Iteration i = {}".format(i))
> out[i] = in0[i]
>
> The printed results in the grc were:
> length of input data: 4 definitely an indication of error
> For the Iterations it printed i = 0,1,2,3,4 and broke with an Error
> stating index 4 is out of bound for axis 0.
> Obviously, my input/output profile specification must be the problem.
>
> I will appreciate any help or suggestions.
>
> Thank you!
> George
>
>
>
Full Modem Lifecycle Development
GNU Radio - I'm new to GNU Radio and have been impressed with it! It seems like GNU Radio is a block based processing framework and I was interested in using it for modem development. I would normally create a C/C++ simulation all from scratch, but I'd have to build my own modem development environment. Does anyone know if the GRN Radio framework supports full modem lifecycle development? For instance, here are a few of the features that would need to be supported: 1. floating point implementation 2. fixed-point implementation 3. optimization of bit-widths in fixed-point implementation 4. BER performance measurements 5. acquisition performance measurements 6. performance measurements under degraded conditions 7. performance measurements under multipath conditions 8. automated performance testing of all of the above 9. distributed performance testing across multiple workstations 10. HW accelerated assisted distributed performance testing 11. etc. Sang Go (GVoice 571-303-9396)
GRU module removed, what can I do please ?
Hello, first of all I am surly not a gnuradio guru, not a python guru. I use some scripts written by other peoples Until last week, all was ok. After an update ( Kali on raspberry).. I have removed gnuradio, python3.8 ... and afte, a new install via apt ( gnuradio, gnuradio-dev osmo-sdr .. python3.10 ..) I still get the error : cannot import gru module from gnuradio. To check, I start by hand in python3 the other imports from gnuradio. gr, digital, filters ... All them work except "gru" As I can see, after spent hours and hours, this gru module is removed from gnuradio. (for the moment I don't understand gnuradio / modules and their goals) What can I do please ? OS: raspi-kali 5.15.44 Debian Kali-pi (2022-07-03) GR Installation Method: apt install ( gnuradio, gnuradio-dev python3 ..) GNU Radio Version 3.10 (maint-3.10) Thank you
Re: GRU module removed, what can I do please ?
Hi Jean-Philippe - did you change your PYTHONPATH from 3.8 to 3.10? Also, please check the subversion of gnuradio-dev, e.g., apt list gnuradio-dev and the 3.10 should expand to something which looks like this 3.10.2.0-1+b2 -- Cinaed On 7/21/22 18:25, Jean-Philippe Buchet wrote: Hello, first of all I am surly not a gnuradio guru, not a python guru. I use some scripts written by other peoples Until last week, all was ok. After an update ( Kali on raspberry).. I have removed gnuradio, python3.8 ... and afte, a new install via apt ( gnuradio, gnuradio-dev osmo-sdr .. python3.10 ..) I still get the error : cannot import gru module from gnuradio. To check, I start by hand in python3 the other imports from gnuradio. gr, digital, filters ... All them work except "gru" As I can see, after spent hours and hours, this gru module is removed from gnuradio. (for the moment I don't understand gnuradio / modules and their goals) What can I do please ? OS: raspi-kali 5.15.44 Debian Kali-pi (2022-07-03) GR Installation Method: apt install ( gnuradio, gnuradio-dev python3 ..) GNU Radio Version 3.10 (maint-3.10) Thank you
