qpsk demodulator for high data rate

[zainabmaghraby]

i tried to make qpsk demodulator on flex rio pxie 7965 using rf communication library but i face a problem of max data rate the maximum data rate is 10M while what i need is 15M i use the example on ni site {PSK demodulator} 

any help can i modify the example to get high data rate

[dbell0971]

Hi Zaina,

I'm assuming you mean this example found under NI-Labs and the RF Communications Library:

M-PSK Demodulator

https://decibel.ni.com/content/docs/DOC-16738

Can you give us more information about what hardware you're using?  I see that you're using the 7965R, it would be helpful to know what chassis and VSA you're using.  Also, do you have the LabVIEW FPGA Module?  Editing the FPGA VI or the bitfile will require it.

Thanks,

David B

National Instruments

Applications Engineer

[zainabmaghraby]

thnx for ur concern

yes iam using this example with VSA PXIe 5663e and the chasses is PXIe-8135

[zainabmaghraby]

and about the FPGA module yes i have pxie-7965 module 🙂

[dbell0971]

Hi Zaina,

A couple of quick things, I think my question was misunderstood, you'll need the LabVIEW FGPA software for editing the code, not just the 7965R.

What loop rates are you currently running?  It looks like the default is 32 MHz and 20 MHz, have you changed these?  Can you try increasing them and changing your IQ rate/Symbol Rate accordingly?  

Thanks,

David Bell

National Instruments

Applications Engineer

[zainabmaghraby]

yes i have labview fpga sw 

actually i need the freqency to be 720Mhz with data rate 16Mhz this is do not work with loop clk 32M and 20M the max i got was 10Mhz for data rate

when i check the report from the compilation when using 32M and 20M clk the report said that max clk is 23M instead of the 20M

then i remove  the offset part from the demodulator to act as non-coherent demodulator and i got the maximum data rate 13M

[dbell0971]

Hi Zaina,

As you may have seen before, this M-PSK FlexRIO demodulator was developed by NI-Labs.  Have you thought about posting there?  Since they developed the code, they may be better equipped to answer your questions.

Thanks,

David B

National Instruments

Applications Engineer

[zainabmaghraby]

sorry where could i post my question ?!

[dbell0971]

Hi Zaina,

Here's the link below:

https://decibel.ni.com/content/groups/ni-labs?view=discussions

If you take a look through their information, you'll find that they are the creators of the RF Communications Library, the basis for the MPSK Demodulator.  I'd recommend creating a new discussion there.

Thanks,

David B.

National Instruments

Applications Engineer