[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss-gnuradio] Re: Freq in real world vs. Freq in the SW

From: Milo Wong
Subject: [Discuss-gnuradio] Re: Freq in real world vs. Freq in the SW
Date: Mon, 21 Sep 2009 16:28:20 -0700
User-agent: Thunderbird (X11/20090817)

Oh, There was a typo in my previous description: The sub-carrier freq I set in SW is 4MHz not 2MHz

(i.e. 4MHz sub-carrier set in SW results in a 50KHz sub-carrier on FFT.). Please let me know if you have any comments. Thank you.


Milo Wong wrote:
Hi folks,

I wrote a amplitude modulation block and here's an interesting problem:

It seemed that the Freq showed on the plot of post modulation FFT is always (1/80) of the freq I set in the SW. For example, If I set the sub-carrier freq to 2MHz, and use a message signal (constant 1.0)to modulate that, I can only get a 50KHz sub-carrier showed on FFT plot. I've attached my plots(both in freq and time domain).

Below are the test results:
freq. in post-mod FFT       freq. set in SW
    12.5k                             1M
     25k                               2M
     50k                               4M

Is there anyone who has some ideas or comments? Thank you!




reply via email to

[Prev in Thread] Current Thread [Next in Thread]