Re: [Discuss-gnuradio] high speed frequency hopping

[Eric Blossom]

On Wed, Mar 14, 2007 at 07:28:26AM -0700, John Bratteli wrote:
> Hi everyone,
> 
> I'm working on something to hop through a large range
> of frequencies identifying signals.  I was testing to
> see how fast I could hop by capturing the data from
> the USRP and sending it to a null sink.  I found that
> it takes .38  seconds, plus the time length I set to
> get data, to run a capture.  I'd like to improve that
> considerably.  Any idea?
> 
> Thanks,
> John Bratteli
> Texas A&M-Commerce

The inband-signaling work-in-progress will help with this.
The limiting factor will be the settling time of the PLL's on the
front ends.  On the RFX-* this is on the order of 100us.  (Matt, did I
remember this correctly?)  Note that in cases where the next frequency
is within the currently selected IF passband, tuning is effectively
instantaneous.  We just have to change the DDC center frequency.

Eric