Hi evrybdy,
I am new to this grp.I am working on a project involving
demodulation of msk signals.The transmitter has been implemented using a
AD9851 DDS chip.The transmitter switches between 16MHz and 24MHz depending
on the incoming bits.At the receiver,I am using AD6620 to downconvert the
signal to baseband and then AD6640 A to D converter digitizes the signal.I
intend to do the baseband processing in DSP.Can anyone please provide with
information on the different methods of doing this.
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msk demodulation
Started by ●July 11, 2005
Reply by ●July 11, 20052005-07-11
harsh17 wrote:> Hi evrybdy, > I am new to this grp.I am working on a project involving > demodulation of msk signals.The transmitter has been implemented using a > AD9851 DDS chip.The transmitter switches between 16MHz and 24MHz depending > on the incoming bits.At the receiver,I am using AD6620 to downconvert the > signal to baseband and then AD6640 A to D converter digitizes the signal.I > intend to do the baseband processing in DSP.Can anyone please provide with > information on the different methods of doing this. > > > > This message was sent using the Comp.DSP web interface on > www.DSPRelated.comHere are three ways of performing noncoherent MSK demodulation: 1. Delay and multiply 2. Discriminate 3. Mark and space filters John
Reply by ●July 13, 20052005-07-13
Thanks John,
Can u please suggest some resources where i can find a little
more detail on these techniques.Also how can i detect msk coherently?
Regards
Harshad
>harsh17 wrote:
>> Hi evrybdy,
>> I am new to this grp.I am working on a project involving
>> demodulation of msk signals.The transmitter has been implemented using
a
>> AD9851 DDS chip.The transmitter switches between 16MHz and 24MHz
depending
>> on the incoming bits.At the receiver,I am using AD6620 to downconvert
the
>> signal to baseband and then AD6640 A to D converter digitizes the
signal.I
>> intend to do the baseband processing in DSP.Can anyone please provide
with
>> information on the different methods of doing this.
>>
>>
>>
>> This message was sent using the Comp.DSP web interface on
>> www.DSPRelated.com
>
>Here are three ways of performing noncoherent MSK demodulation:
>
>1. Delay and multiply
>2. Discriminate
>3. Mark and space filters
>
>John
>
>
This message was sent using the Comp.DSP web interface on
www.DSPRelated.com
Reply by ●July 13, 20052005-07-13
>>harsh17 wrote: >>> Hi evrybdy, >>> I am new to this grp.I am working on a project involving >>> demodulation of msk signals.The transmitter has been implementedusing>a >>> AD9851 DDS chip.The transmitter switches between 16MHz and 24MHz >depending >>> on the incoming bits.At the receiver,I am using AD6620 to downconvert >the >>> signal to baseband and then AD6640 A to D converter digitizes the >signal.I >>> intend to do the baseband processing in DSP.Can anyone please provide >with >>> information on the different methods of doing this.>> >>Here are three ways of performing noncoherent MSK demodulation: >> >>1. Delay and multiply >>2. Discriminate >>3. Mark and space filters >> >>John >>Thanks John, Can u please suggest some resources where i can find a little more detail on these techniques.Also how can i detect msk coherently? Regards Harshad This message was sent using the Comp.DSP web interface on www.DSPRelated.com
Reply by ●July 13, 20052005-07-13
harsh17 wrote:> Thanks John, > Can u please suggest some resources where i can find a little > more detail on these techniques.Also how can i detect msk coherently? > > Regards > Harshad > > > >harsh17 wrote: > >> Hi evrybdy, > >> I am new to this grp.I am working on a project involving > >> demodulation of msk signals.The transmitter has been implemented using > a > >> AD9851 DDS chip.The transmitter switches between 16MHz and 24MHz > depending > >> on the incoming bits.At the receiver,I am using AD6620 to downconvert > the > >> signal to baseband and then AD6640 A to D converter digitizes the > signal.I > >> intend to do the baseband processing in DSP.Can anyone please provide > with > >> information on the different methods of doing this. > >> > >> > >> > >> This message was sent using the Comp.DSP web interface on > >> www.DSPRelated.com > > > >Here are three ways of performing noncoherent MSK demodulation: > > > >1. Delay and multiply > >2. Discriminate > >3. Mark and space filters > > > >John > >For coherent demodulation, take a look at COHERENT DEMODULATION OF FREQUENCY-SHIFT KEYING WITH LOW DEVIATION RATIO, R. de Buda, IEEE Trans Comm, June 1972 John
Reply by ●July 13, 20052005-07-13
john wrote:> > harsh17 wrote: > >>Thanks John, >> Can u please suggest some resources where i can find a little >>more detail on these techniques.Also how can i detect msk coherently? >> >>Regards >>Harshad >> >> >> >>>harsh17 wrote: >>> >>>>Hi evrybdy, >>>> I am new to this grp.I am working on a project involving >>>>demodulation of msk signals.The transmitter has been implemented using >> >>a >> >>>>AD9851 DDS chip.The transmitter switches between 16MHz and 24MHz >> >>depending >> >>>>on the incoming bits.At the receiver,I am using AD6620 to downconvert >> >>the >> >>>>signal to baseband and then AD6640 A to D converter digitizes the >> >>signal.I >> >>>>intend to do the baseband processing in DSP.Can anyone please provide >> >>with >> >>>>information on the different methods of doing this. >>>> >>>> >>>> >>>>This message was sent using the Comp.DSP web interface on >>>>www.DSPRelated.com >>> >>>Here are three ways of performing noncoherent MSK demodulation: >>> >>>1. Delay and multiply >>>2. Discriminate >>>3. Mark and space filters >>> >>>John >>> > > > For coherent demodulation, take a look at > > COHERENT DEMODULATION OF FREQUENCY-SHIFT KEYING WITH LOW DEVIATION > RATIO, R. de Buda, IEEE Trans Comm, June 1972 > > John >If there's anyone in the Portland, Oregon or Worcester, Massachusetts area with time on their hands chapter three of my Master's thesis "A DGPS/Radiobeacon Receiver for Minimum Shift Keying with Soft Decision Capabilities" contains, if not a tutorial, then at least a blow-by-blow account of how to do it, and Appendix B has MC68HC11 assembly code that not only serves as a working example of a demodulator but also an example of code that would be a nightmare in a production environment. I'd love to see those two sections scanned in, cleaned up, and posted on a website someplace. I'm quite short of round tuits around here, but I've seen questions on this group and on the rec.radio.amatuer.homebrew asking for information and there doesn't seem to be anything good on the net. -- ------------------------------------------- Tim Wescott Wescott Design Services http://www.wescottdesign.com
