Re: [Discuss-gnuradio] Reading carrier frequency

[Eric Blossom]

On Wed, Sep 10, 2008 at 11:46:26PM -0600, Gnu Radio Explorer wrote:
> Hi,
> I am new to GNU radio and want to experiment. From the mailing lists, I
> understood that the carrier frequency offsets change over time but that
> those offsets are within +/- 20ppm of the center frequency. Suppose I use
> two USRP boards; one for transmission and another for reception of signals.
> I want to know how I can read the carrier frequency of  the transmitted
> signal on the receiver side through a python or C++ program. Is there any
> program to do this? Or, which library routine can I use for this purpose?
> 
> Appreciate any kind of help you may provide on this.
> 
> Thanks.
> 
> G.

This is a FAQ that needs an answer.  Can someone please write
something up on carrier tracking and symbol timing recovery and post
it to the wiki?

Bottom line: there will always be a frequency offset between any two
radios and part of the receiver's job is to handle it.  There's a ton
of literature on this as well as complete text books.  In the simplest
case it's a PLL to track the carrier, but oftentimes it's more
complicated than that.

Eric