Re: GNURadio N210 UHD Sink input as a number.

[Marcus D. Leech]

On 04/10/2020 04:35 AM, Phan Anh wrote:

Hi there. Please kindly help me with this minor problem as I am very new to USRP and GNURadio.

I have a number output from a series of block for FFT (Log Power FFT) which is the dominant frequency obtain from the FFT spectrum saying e.g. 150 MHz. I want to use this number directly as the input frequency for UHD Sink to transmit a pure sine signal at that freq. I have been searching for a while and could not find any solution for this on GNURadio. Please kindly advise.

I *THINK* what you're asking is:

I have an FFT bin-number that corresponds to the strongest input frequency, and I want to convert that into an actual frequency.  How about
  some simple arithmetic?  That might work.

You know your center frequency.  You know your bandwidth.  You know that the FFT represents  frequencies from:

Fc - bandwidth/2  to Fc + bandwidth/2

You know how many bins are in your FFT, so you know what the frequency-increment is.   Arithmetic.

Moreover, I want to insert a delay block between each transmit and receive phase. The process could be like this: receive + FFT + [delay = 5 ms] + UHD Transmit in 50 ms + ... and so on. Is there any way to do this directly by GNURadio?

I really appreciate any support from you guys.

Best regards

Anh

--

Anh Phan

Institute of Electrical Engineering, Vietnam

The University of Melbourne, Australia
University of New South Wales, Australia

Tel: +84 165 911 0465