Spread Spectrum and Modulation chain- Urgent

[ethen99]

Hi everyone

To start with the modulation toolkit I have made the attached vi to familiarize myself with modulation blocks. The following block contains a bit generator+DSSS encoder+PSK modulation+white noise+PSK demodulation+DSSS decoder

As can be seen I have started with a basic example but I don't know why I get Error -21824 with PSK modulation block.Would u plz help me with this vi? and wud u plz let me know how can I change this vi to do QPSK modulation

Many thanks

 

[ethen99]

Hi

I reaaly appreciate any help for this vi

[Larry.C]

Hi en99,

I have taken a look at your VI and have found what I think is the reason for your error message. On the MT modulation block I do not think you can wire in a constant as a cluster of system parameters, instead it must be generated using the MT Generate System Parameters.vi found in the modulation pallette.

I have quickly replaced your constant and also wired in to the demodulate vi (also requires system param.) and attached it to this post as 11new.vi.

I hope this helps.

Kind Regards,

[Larry.C]

Hi en99,

I also found a nice community example experiment which does both BPSK and QPSK modulation. It might be worth taking a look to help understand how to set up your VI.

You can find the example here.

Kind Regards,

[ethen99]

Dear Larry

Many thanks for your quick reply. I have access to LabVIEW 2010 .wud u plz save your vi for 2010 version

[Larry.C · Accepted solution]

Hi en99,

I have attached a 2010 version to this post.

Kind Regards,

[ethen99]

Many thanks Larry

[gizem11]

i have a the same problem.but i cant solve. Anyone can help me? how i can solve?

[Adam.B]

Hi gizem11,

The problem is caused by wiring a constant into the PSK system parameters input, as Larry explained you must generate this data using the "MT Generate System Parameters" VI.