Re: [Discuss-gnuradio] Loops in graphs? Do we need them?

[Eric Blossom]

On Tue, Feb 08, 2005 at 10:27:40PM +0100, Thomas Traber wrote:
> Hi Achilleas,
> > The reason (imho) of the existence of PLLs (and similar non-linear 
> > feedback loops) is that in old analog systems, such an option was not 
> > there (ie, taking the arctan of a signal).
> 
> Maybe you are right and I am thinking to much in hardware.
> It might be that almost all digital signal processing task
> can be done without feedback.
> 
> Loops which cover only few blocks are better hard coded in
> C. 
> 
> BTW: There are files like GrAGC.h, GrCostasLoop.h and
> GrComplexVCOMixer.h in src/lib/general. I do not know how
> they are used.

They are from the 0.x code base and need to be ported.
They're still in CVS as a reminder to either fix them or kill them.

Eric