regarding modulation tool kit

[sree_405]

Hi,
I am Sreenivasulu.i need example for generating OOK and GMSK modulation.
i instaled modulation tool kit,in that example VIs this two are not there.
if any one having this two please upload.


Thanking you sir
Sreenivasulu

[Ana P]

Hi Sreenivasulu,

Are you using the FPGA in this card? Or are you using only the instrument’s drivers? The GMSK modulation format is MSK using a Gaussian shaping filter. So you can have a look at the MSK example and notice that one of the options for the shaping filter is Gaussian. You can find the examples at \National Instruments\LabVIEW 8.5\examples\Modulation\RFSG examples. For OOK modulation, one easy option would be to use the example for ASK and select the constellation to be 2. Then you can set the amplitudes to be 0 and a specific value for the symbols. This is basically what Vinay suggested in your other post. I hope this is helpful,

[sree_405]

Hi Ana P,
I tried for GMSK,but i din't find any freqency deviation.as per my knowledge for GMSK frequency chenge and phase changes has to be there.
If u have time plz do need full with LabVIEW 8.2 VI
For OOK how i have to specify 0 amplitude for bit '0'.in ask constellation to be 2 means M value is 2, i am correct.in this also i am getting problem.
please help me to come out from this problem.


Thnaking you sir

[Speedy_Badger]

Sreenivasulu,

You are correct that MSK, regardless of what pulse shaping filter is used, modulates the message in both frequency and phase, specifically changing the phase in a continuous linear fashion. The frequency deviation is handled automatically for you in our MSK  modulation and demodulation VIs and is defined as follows:

Symbol Frequency Deviation = +/- (Symbol Rate / 4)

As you can see, this is identical to CPFSK with an index of modulation h = 0.5. The frequency deviations (represented as symbols) are then converted to phase increments.

You can confirm all of this by opening up the MT Modulate MSK VI and exploring how we set the modulation up. Obviously the the demodulation of MSK, and GMSK, takes all of this in to account.

As for the OOK, you will have to be much more specific about what issue you are currently running into.

Best Regards,

[Aht22]

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@Ana P wrote:

Hi Sreenivasulu,

Are you using the FPGA in this card? Or are you using only the instrument’s drivers? The GMSK modulation format is MSK using a Gaussian shaping filter. So you can have a look at the MSK example and notice that one of the options for the shaping filter is Gaussian. You can find the examples at \National Instruments\LabVIEW 8.5\examples\Modulation\RFSG examples. For OOK modulation, one easy option would be to use the example for ASK and select the constellation to be 2. Then you can set the amplitudes to be 0 and a specific value for the symbols. This is basically what Vinay suggested in your other post. I hope this is helpful,

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hi Ana P,

according to your opinion,there is no extra filter is required to gmsk  transmission and reception,just select Gaussian filter as pulse shaping filter is enough.how can i set the BT value and symbol rate and samples per symbol if i dont know the transmitter parameter.

i have also another question if i want to implement msk i select  none for pulse shaping filter options.

thanks in advance.