On Jan 8, 6:28�pm, Vladimir Vassilevsky <antispam_bo...@hotmail.com>
wrote:

> > On Jan 8, 9:49 am, Vladimir Vassilevsky <antispam_bo...@hotmail.com>
> > wrote:
>
> >>There are only two approaches: coherent (where Fi is used) and
> >>incoherent (where dFi/dt is used). There is an infinite number of the
> >>equivalent ways for the implementation of each approach.
> > There is a bible on CPM:
> >http://www.amazon.com/Digital-Modulation-Applications-Communications-...
>
> > In it you will see that there is a class of techniques that involve
> > filtering the arbitrary phase baseband CPM data with a set of complex
> > kernels that represent phase transitions corresponding to bit
> > sequences. The decision circuit can choose the filter producing the
> > largest magnitude response to decide what sequence was transmitted.
> > This is sometimes called sequence processing. Its performance can
> > approach coherent as the sequence length gets long, provided that the
> > parameters are not off too much. It's worth a look.
>
> Too many words to describe the simple thing: one can get an estimate of
> phase by observing a window of N symbols. As N goes to the infinity,
> this becomes equivalent to the coherent demodulation.
>
> Vladimir Vassilevsky
> DSP and Mixed Signal Design Consultanthttp://www.abvolt.com- Hide quoted text -
>
> - Show quoted text -

The phase is actually discarded in the decision circuit. It operates
on magnitude only.
John

Reply by Vladimir Vassilevsky●January 8, 20082008-01-08

> On Jan 8, 9:49 am, Vladimir Vassilevsky <antispam_bo...@hotmail.com>
> wrote:
>
>>There are only two approaches: coherent (where Fi is used) and
>>incoherent (where dFi/dt is used). There is an infinite number of the
>>equivalent ways for the implementation of each approach.

> There is a bible on CPM:
> http://www.amazon.com/Digital-Modulation-Applications-Communications-Theory/dp/030642195X
>
> In it you will see that there is a class of techniques that involve
> filtering the arbitrary phase baseband CPM data with a set of complex
> kernels that represent phase transitions corresponding to bit
> sequences. The decision circuit can choose the filter producing the
> largest magnitude response to decide what sequence was transmitted.
> This is sometimes called sequence processing. Its performance can
> approach coherent as the sequence length gets long, provided that the
> parameters are not off too much. It's worth a look.

Too many words to describe the simple thing: one can get an estimate of
phase by observing a window of N symbols. As N goes to the infinity,
this becomes equivalent to the coherent demodulation.
Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

Reply by Randy Yates●January 8, 20082008-01-08

John <sampson164@gmail.com> writes:

> There is a bible on CPM:
>
>

http://www.amazon.com/Digital-Modulation-Applications-Communications-Theory/dp/030642195X
For $204 it better damn well be gold-plated as well.
--
% Randy Yates % "Midnight, on the water...
%% Fuquay-Varina, NC % I saw... the ocean's daughter."
%%% 919-577-9882 % 'Can't Get It Out Of My Head'
%%%% <yates@ieee.org> % *El Dorado*, Electric Light Orchestra
http://www.digitalsignallabs.com

Reply by John●January 8, 20082008-01-08

On Jan 8, 9:49 am, Vladimir Vassilevsky <antispam_bo...@hotmail.com>
wrote:

> isgone wrote:
> > and what are the methods? thanks !just tell me some of them,i need to know
> > some Noncoherent demodulation methods for CPM. your help is appreciated !
>
> There are only two approaches: coherent (where Fi is used) and
> incoherent (where dFi/dt is used). There is an infinite number of the
> equivalent ways for the implementation of each approach.
>
> Vladimir Vassilevsky
> DSP and Mixed Signal Design Consultanthttp://www.abvolt.com

There is a bible on CPM:
http://www.amazon.com/Digital-Modulation-Applications-Communications-Theory/dp/030642195X
In it you will see that there is a class of techniques that involve
filtering the arbitrary phase baseband CPM data with a set of complex
kernels that represent phase transitions corresponding to bit
sequences. The decision circuit can choose the filter producing the
largest magnitude response to decide what sequence was transmitted.
This is sometimes called sequence processing. Its performance can
approach coherent as the sequence length gets long, provided that the
parameters are not off too much. It's worth a look.
John

Reply by Vladimir Vassilevsky●January 8, 20082008-01-08

isgone wrote:

> and what are the methods? thanks !just tell me some of them,i need to know
> some Noncoherent demodulation methods for CPM. your help is appreciated !

There are only two approaches: coherent (where Fi is used) and
incoherent (where dFi/dt is used). There is an infinite number of the
equivalent ways for the implementation of each approach.
Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

Reply by John●January 8, 20082008-01-08

On Jan 7, 10:09 pm, "isgone" <isg...@hotmail.com> wrote:

> and what are the methods? thanks !just tell me some of them,i need to know
> some Noncoherent demodulation methods for CPM. your help is appreciated !

I won't fill out your list, but I'll mention a couple of interesting
ones -- average matched filter and sequence detector.
John

Reply by isgone●January 7, 20082008-01-07

and what are the methods? thanks !just tell me some of them,i need to know
some Noncoherent demodulation methods for CPM. your help is appreciated !