Okay, well best of luck with that. I hope the B200 has the necessary capabilities to do what you need.
Here are the links to block writing, hope this helps. https://wiki.gnuradio.org/index.php/OutOfTreeModules https://wiki.gnuradio.org/index.php/BlocksCodingGuide Thank you, Alex On Fri, Jul 9, 2021 at 3:35 AM Pham Van Dung <dungdk...@gmail.com> wrote: > Yes, I use it for another project which is a pulse FMCW radar project > > In this project, we need an LFM with receiving time (dead-time) for > testing the function of the radar (transmitter and receiver etc..) > > Do you have any tutorial to modify the block of GNU Radio? I am a hardware > guy so it may take some time to implement this work so I would > appreciate it if you can help me how to modify it > > Thank you very much > > > On Thu, Jul 8, 2021, 18:07 Alex Batts <battsale...@gmail.com> wrote: > >> What on the other device are you trying to measure? Are you simply >> attempting to see if you can receive a signal, or are you trying to receive >> information of some kind? >> >> Generating an LFM signal is no problem, and modifying the source code is >> a good way to go if that's all you want to do. You are right though about >> the 56 MHz bandwidth, and the sample rate may affect your chirp >> repetition frequency. >> >> Thanks, >> >> Alex >> >> On Thu, Jul 8, 2021 at 11:20 AM Pham Van Dung <dungdk...@gmail.com> >> wrote: >> >>> Thank Alex for your answer, >>> >>> For the second question, I will not design a pulse doppler radar with a >>> linear FM pulse. But I wonder that I could generate an LFM signal (to >>> measure another RF device at 1GHz) using Ettus B200? >>> >>> Due to the limit of the hardware capabilities, I think I can only >>> generate an LFM with a maximum ~ 56 MHz sweep bandwidth (if possible). >>> >>> My approach is the modification of the source code of the FMCW block >>> using OutOfTreeModules with gr_modtool, >>> >>> In which I will add the deadtime at the end of each FMCW pulse but I >>> think I will not trade with my time to do this problem because I have >>> already another solution :D >>> >>> Again, I appreciate your help and time in advance >>> >>> Vào Th 5, 8 thg 7, 2021 vào lúc 16:16 Alex Batts < >>> battsale...@gmail.com> đã viết: >>> >>>> Hello, >>>> >>>> It has been a while since I used the FMCW block in the Radar toolbox, >>>> but from what I can remember, the three samples sections are defining the >>>> percentage of the signal you want distributed in each of those sections. >>>> For example, if you want 50% of your signal to be CW, and 50% to be >>>> up-chirp, put an equal number of samples in the Samples CW and Samples >>>> up-chirp sections. The number of samples combined with your sample rate and >>>> frequency sweep will determine the slope of the fm chirp. >>>> >>>> There is also a VCO block I'm pretty sure that you can use for more >>>> customizable fmcw radar. >>>> >>>> For your second question, why do you want to add a dead time? My guess >>>> would be because you are trying to do pulse doppler of some sort, but if >>>> not please explain because I would definitely be interested in knowing what >>>> you are attempting to do! If you are trying to do a pulse doppler radar >>>> with a linear fm pulse compression, unfortunately, there isn't much >>>> functionality within GNU Radio for that kind of thing, and SDRs aren't >>>> great for pulse doppler right now. In a few years' time they will, but most >>>> affordable SDRs just don't have the hardware capabilities necessary. FMCW >>>> is the way to go for SDRs because of low peak power needed and because >>>> timing is not as necessary for range disambiguation, which is nice because >>>> of the low sample rates of most SDRs. >>>> >>>> I am not sure you can implement a dead-time within the FMCW signal >>>> generator block, and am not sure that gr-radar has that capability. >>>> However, if you still want to implement a dead-time, you could write a >>>> custom block (GNU Radio has extensive tutorials on how to do this, and only >>>> requires basic knowledge of yaml and c++). I would do something like, >>>> generate a sine wave, and while the sine wave is above a certain threshold, >>>> send the fmcw signal through, else, send a constant 0 through. You would >>>> have to play around with the threshold to get the proper duty cycle and >>>> play around with the frequency of the sine wave to make sure you are >>>> staying in sync with the signal generator, but that is one idea on how I >>>> would do it off the top of my head. >>>> >>>> Can you give me more information on the project and/or what your goals >>>> are? It would help me give more specific advice as opposed to shooting >>>> blindly. >>>> >>>> Thank you, >>>> >>>> Alex >>>> >>>> On Thu, Jul 8, 2021 at 5:44 AM Pham Van Dung <dungdk...@gmail.com> >>>> wrote: >>>> >>>>> Hello all, >>>>> I want to make an FMCW signal generation with GNU Radar toolbox and >>>>> Ettus B200 >>>>> I saw that you have several examples in >>>>> https://github.com/kit-cel/gr-radar/tree/master/examples/simulation, >>>>> but I do not understand the following parameters of the FMCW block >>>>> - Samples CW >>>>> - Samples up-chirp >>>>> - Samples down-chirp >>>>> - Frequency CW >>>>> Second question, if I want to modify the block (I want to add >>>>> dead-time at each pulse of FMCW), How can I do it? >>>>> I appreciate your help and time >>>>> >>>>> >>> >>> -- >>> ----------------------------------------------------------------------- >>> Van-Dung,PHAM >>> >>>
