I'll have to apologize for the misinformation I spread about the signal coming out of the USRP:
yes, you're right; in fact, though the sampling for the TVRX2 is done in real (meaning that you get 100 Million *real* samples per second of your input signal), the digital down conversion chain, which takes that 100MS/s stream, takes the signal and digitally shifts it to *complex* baseband. Which means that, yes, for 5MS/s, you get 5MHz of bandwidth.
You did the right thing and looked at a real-world signal that you knew -- as mentioned, the numbers on the frequency plot's x-axis are arbitrarily set by modifying the sampling rate value in the QT Gui sink block. Thanks for pointing out this mistake!
Best regards,
Marcus
On 16.09.2015 18:27, Gerome Jan L
wrote:
Hi guys,
Actually, that's what I thought too. If I set the UHD: USRP Source samp_rate to 400 Msps, I should expect a maximum bandwidth of 200 kHz. However on my testing, assigning that value in the samp_rate, gives me its bandwidth. For example, I set it to 4 Msps, and I get a 4 MHz of bandwidth. I think I am missing something here. I will be attaching one of my screenshots below.
This is set to a samp_rate of 5 Msps. and I get a bandwidth of 5 MHz. That is from 88 MHz to 93 MHz. Our FM here is separated by 800kHz. Thank you in advance.
Best,
Gerome Jan M. LlamesAspiring Technopreneur | Tech Savvy | Curious
"Because the people who are crazy enough to think they can change the world, are the ones who do." - Steve Jobs
