center frequency computaion for MAPSK transmission

Hi,
I'm working on techniques in order to compute center frequency of MAPSK
transmission. 
I foud work based on the computation of the index of maximum of (fft(s^M))
for MPSK transmission only (M is the modulation order).
Are this formula OK for APSK transmission (like 16QAM or 16 APSK). I don't
think so because different phase values are used in those cases. Otherwise
could you give some help, or usefull link on this subject

Thanks a lot

On May 7, 3:26&#4294967295;pm, "dudu69" <pf_mor...@yahoo.fr> wrote:
> Hi,
> I'm working on techniques in order to compute center frequency of MAPSK
> transmission.
> I foud work based on the computation of the index of maximum of (fft(s^M))
> for MPSK transmission only (M is the modulation order).
> Are this formula OK for APSK transmission (like 16QAM or 16 APSK). I don't
> think so because different phase values are used in those cases. Otherwise
> could you give some help, or usefull link on this subject
>
> Thanks a lot

M=4 is a reasonable choice for various flavors of QAM.

John

dudu69 wrote:

> Hi,
> I'm working on techniques in order to compute center frequency of MAPSK
> transmission.

Use the band edge algorithm, STUPIDENT.

VLV

>On May 7, 3:26=A0pm, "dudu69" <pf_mor...@yahoo.fr> wrote:
>> Hi,
>> I'm working on techniques in order to compute center frequency of
MAPSK
>> transmission.
>> I foud work based on the computation of the index of maximum of
(fft(s^M)=
>)
>> for MPSK transmission only (M is the modulation order).
>> Are this formula OK for APSK transmission (like 16QAM or 16 APSK). I
don'=
>t
>> think so because different phase values are used in those cases.
Otherwis=
>e
>> could you give some help, or usefull link on this subject
>>
>> Thanks a lot
>
>M=3D4 is a reasonable choice for various flavors of QAM.
>
>John
>

Hi John

thanks for your help. Could you telle me what is D in your expression ? Is
it the number of possible state of phase in IQ constellation ?

On May 9, 2:17&#4294967295;pm, "dudu69" <pf_mor...@yahoo.fr> wrote:
> >On May 7, 3:26=A0pm, "dudu69" <pf_mor...@yahoo.fr> wrote:
> >> Hi,
> >> I'm working on techniques in order to compute center frequency of
> MAPSK
> >> transmission.
> >> I foud work based on the computation of the index of maximum of
> (fft(s^M)=
> >)
> >> for MPSK transmission only (M is the modulation order).
> >> Are this formula OK for APSK transmission (like 16QAM or 16 APSK). I
> don'=
> >t
> >> think so because different phase values are used in those cases.
> Otherwis=
> >e
> >> could you give some help, or usefull link on this subject
>
> >> Thanks a lot
>
> >M=3D4 is a reasonable choice for various flavors of QAM.
>
> >John
>
> Hi John
>
> thanks for your help. Could you telle me what is D in your expression ? Is
> it the number of possible state of phase in IQ constellation ?

There isn't supposed to be a 3 or a D in there, I don't know how that
got added. What you do is raise the complex baseband to the fourth
power, and you should find a tone at 4X the frequency offset.

John

>On May 9, 2:17=A0pm, "dudu69" <pf_mor...@yahoo.fr> wrote:
>> >On May 7, 3:26=3DA0pm, "dudu69" <pf_mor...@yahoo.fr> wrote:
>> >> Hi,
>> >> I'm working on techniques in order to compute center frequency of
>> MAPSK
>> >> transmission.
>> >> I foud work based on the computation of the index of maximum of
>> (fft(s^M)=3D
>> >)
>> >> for MPSK transmission only (M is the modulation order).
>> >> Are this formula OK for APSK transmission (like 16QAM or 16 APSK).
I
>> don'=3D
>> >t
>> >> think so because different phase values are used in those cases.
>> Otherwis=3D
>> >e
>> >> could you give some help, or usefull link on this subject
>>
>> >> Thanks a lot
>>
>> >M=3D3D4 is a reasonable choice for various flavors of QAM.
>>
>> >John
>>
>> Hi John
>>
>> thanks for your help. Could you telle me what is D in your expression ?
I=
>s
>> it the number of possible state of phase in IQ constellation ?
>
>There isn't supposed to be a 3 or a D in there, I don't know how that
>got added. What you do is raise the complex baseband to the fourth
>power, and you should find a tone at 4X the frequency offset.
>
>John
>

Thanks !
but I thought that the fourth power corresponds only for a QPSK (M=4
possible phase state) transmission. anyway, I will try with M=4