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

[Prateek Dayal]

Hi,

I also need to track the phase of a sinusoidal signal for my work on
NTSC demod. How about applying some kind of linear regression and then
estimating the phase vs time relationship. As phase varies linearly
with time, I think that this should be possible.

Regards,

Prateek 


On Mon, 07 Feb 2005 23:53:55 -0600, Rick Parrish <address@hidden> wrote:
> Achilleas Anastasopoulos wrote:
> 
> > For instance, a PLL is a non-linear feedback filter that tracks the
> > phase of an input sinusoid (approximately).
> > In a DSP implementation we can recover the phase of the complex IQ
> > signal and operate on it using simple FIR or IIR filters.
> 
> A PLL can also refer to other forms of feedback. Some loops might be
> more properly called PID (proportional-integral-derivative). In the case
> of some code I use, the PLL is actually used for clock recovery by
> operating on a digital signal captured in a sample stream.
> 
> Which reminds me ... I need to throw together some code that does symbol
> and clock recovery for a fairly low bit rate signal - a 1200 baud FFSK
> signal for an MPT1327 data channel. I'd like to do it without resorting
> to such heavy fisted tactics as an FFT or FIR filter. Anyone have any
> suggestions? I have a half-a**'d solution now but I'd like something
> closer to 100%. I'm not crazy about multiply-accumulate correlator
> techniques either.
> 
> -rick
> 
> 
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-- 
Prateek Dayal
B.Tech 4th Year
ECE
IIT Guwahati

www.geocities.com/pmd_iitgw