Re: [Discuss-gnuradio] CPM timing recovery

[Achilleas Anastasopoulos]

David,

as I explained in my earlier email,
the power you have to raise your signal is not always 2.
If h = 1/4 you need to raise your signal to the power 4.
In general ig h=N/D, you raise it to D.

Achilleas

David Scaperoth wrote:
>     BTW, are you using the cpm.py hierarchical block that is
>     on the trunk? If yes, I attach a simple python code that
>     demonstrates the spectral line generation for a 4-CPFSK
>     with h=1/2.
>
>  
>  
> I definitely see the spectral lines for your case, which I believe is 
> considered an MSK modulation.  Unfortunately, I cannot assume that the 
> signal will be MSK.  When I change the index to another often used CPFSK 
> index of 1/4, I noticed that the spectral lines go away...
>  
> any thoughts?
>  
> david
>  
>  
>
>            #self.connect (self.src,self.b2B,self.mod_old,self.fft_old)
>            #self.connect (self.b2B,self.mod_new ,self.fft_new)
>            self.connect (self.src,self.b2B,self.mod_new,self.fft_new)
>            self.connect (self.mod_new,(self.nonl,0))
>            self.connect (self.mod_new,(self.nonl,1))
>            self.connect (self.nonl ,self.fft_new1)
>
>
>
>
>
>     if __name__ == '__main__':
>        app = stdgui.stdapp (cpm_graph, "test CPM graph")
>        app.MainLoop ()

--
_______________________________________________________
Achilleas Anastasopoulos                        
Associate Professor
EECS Department               Voice : (734)615-4024
UNIVERSITY OF MICHIGAN        Fax   : (734)763-8041
Ann Arbor, MI 48109-2122      E-mail: address@hidden
URL: http://www-personal.engin.umich.edu/~anastas/      
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