MT QAM transmitter with upconverter

[shirin91]

hi

im trying to use MT QAM transmitter vi to generate 16 QAM with no channel. in this Vi the QAM signal is not upconverted so i tried to add MT baseband upconverter but i recieved error which i attached in picture. i know that i need to specify Fs to get ride of this error. could anyone help please.

regards

[NIRebecca]

Hey Shirin91,

Have you tried modifying your sample rate? As the error code states this needs to be greater than double the carrier frequency - what rates are you using, and waht carrier frequency are you expecting?

The same error is discussed in this forum.

<nierror code="-20578">
Invalid dt; To satisfy the Nyquist criterion, the input sampling rate (1/dt) must be strictly greater than 2 * carrier frequency

Let us know how you get on,

Rebecca

[shirin91]

hi

thanks for your replay. i didnt know how to modify Fs for upconverter baseband block. instead of it i multiply my modulated baseband signal with sinewave which i easily modified carrier frequency and Fs.

now im trying to save the result in txt file but it gives me error. any clue please.

regards

[NIRebecca · Accepted solution]

Hey Shirin91, 

What error are you receiving? It might be worth adding some error handling in your VI too so you can see where this error originates from. I've connected the error wire across and also tidied up the front panel a little in the attached VI.

I tested the VI without specifying a file path (just leaving this empty). A pop up appears asking me where to save the data as expected. I can select a .txt file (log.txt also attached). 

Hope this helps,
Rebecca