NI Home
Cart Cart | Help
Hello Events Academic NI Developer Zone Support Solutions Products & Services Contact NI MyNI
You are here: 
NI Home > NI Developer Zone > NI Discussion Forums


Reply
Member
jawadkhokhar
Posts: 2
0 Kudos

Number of recovered bits is less than the input bits in Demodulation of PSK- using Modulation Toolkit

Whenever I try to demodulate any given complex baseband signal generated through the MT modulate PSK.vi and demodulate it using MT Demodulate PSK.vi , the number of recovered bits is always lesser than the number of bits initially given in the input bit stream.

I would be grateful to anyone who has a solution to this problem.

 

Thanks

 

Jawad

Active Participant
Jim_S
Posts: 229
0 Kudos

Re: Number of recovered bits is less than the input bits in Demodulation of PSK- using Modulation Toolkit

Hello Jawad,

 

If you could post your code implementing this modulation and demodulation, it will make it easier to see why this is occurring. Also which bits are being lost and where are these bits located in the data?

 

JimS.


Jim St
National Instruments
RF Product Support Engineer
Member
jawadkhokhar
Posts: 2
0 Kudos

Re: Number of recovered bits is less than the input bits in Demodulation of PSK- using Modulation Toolkit

Hello JimS

 

Please check the attached file.

 

Thanks

 

Jawad

Active Participant
Chris_W.
Posts: 300
0 Kudos

Re: Number of recovered bits is less than the input bits in Demodulation of PSK- using Modulation Toolkit

Hi Jawad,

 

It looks like the issue probably lies in the fact that your bistream has no guard bits or synch bits, which should ensure that the message information gets pushed through the filters properly. What I would do is to take a look at the example program named "MT PSK Transceiver (One Shot).vi" which is one of the example programs that installs with the modulation toolkit. You can find it at the file location C:\Program Files\National Instruments\LabVIEW XXXX\examples\Modulation\simulation examples\Interactive, for whichever version of LabVIEW you're using (hence the XXXX). This example goes through and sets up all needed parameters to simulate a one shot generation/recieve.

 

Chris W

By using this web site, you accept the Terms of Use for this web site. Please read these Terms of Use carefully before using any part of this site. Please go here for information on ni.com's copyright infringement policy.
My Profile | Privacy | Legal | Contact NI © 2011 National Instruments Corporation. All rights reserved.    |    E-Mail this Page E-Mail this Page