Re: Wide spectrum sweep

[Kyeong Su Shin]

Hello Andrea:

It is possible, but the best practice depends on the SDR source block that you are using (and also the SDR receiver hardware that you are using). 

For an example, you can treat the center frequency of the SDR source block as a variable and regularly update that value by using blocks like "Probe Signal" & "Function Probe" (See the GNU Radio WIki for the details). You can also write additional "Embedded Python Block"s to orchestrate the process (again, see the GNU Radio Wiki for the details). This works on most SDR source blocks.

The problem of the above method is, however, that it is difficult to know when exactly the retuning is happening (the hardware will not retune its frequency immediately upon the request. Internal buffers of GNU Radio is also a concern). So, you have to make some empirical guesses, and it is best to be avoided.

Blocks like "UHD Source" (for USRPs) support more advanced control features via message and tag interfaces of GNU Radio. With that, you can control the retuning process more precisely. See: https://wiki.gnuradio.org/index.php/USRP_Source . The problem is that not every SDR receiver has such blocks.

Regards,

Kyeong Su Shin

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보낸 사람: Andrea Valori <avalori@gmail.com> 대신 Discuss-gnuradio <discuss-gnuradio-bounces+ksshin=postech.ac.kr@gnu.org>
보낸 날짜: 2021년 12월 9일 목요일 오후 11:36
받는 사람: discuss-gnuradio@gnu.org <discuss-gnuradio@gnu.org>
제목: Wide spectrum sweep

 

Dear All,

I am trying to acquire a wide spectrum (wider than the bandwidth of the SDR).

This requires a scan over the tuning frequency. Is it possible to obtain this in a single flowgraph? Possibly even with a GUI?

I tried to start from this old post, but could not reach a good working stage...

https://lists.gnu.org/archive/html/discuss-gnuradio/2018-03/msg00314.html

Thanks in advance