Question on FFT

GNU Radio
1

Hi All,

I wanted to work on FFT using gnuradio. I have a question. Why there is
only one frequency shown in plot ? why negative frequency is not being
displayed ? I have attached picture of GRC implementation and FFT plot
as
well.

Best Regards,
Sam

2

On 08/17/2012 11:45 AM, Sam mite wrote:

Hi All,

I wanted to work on FFT using gnuradio. I have a question. Why there is
only one frequency shown in plot ? why negative frequency is not being
displayed ? I have attached picture of GRC implementation and FFT plot as
well.

So, the blue color means complex floats. The signal source is not
producing sin(t), its producing e^jwt

-josh

3

On 17 Aug 2012 14:45, Sam mite wrote:

Hi All,

I wanted to
work on FFT using gnuradio. I have a question. Why there is only one
frequency shown in plot ? why negative frequency is not being displayed
? I have attached picture of GRC implementation and FFT plot as well.

Best Regards,
Sam

Because there’s no negative frequency component
in your sample stream.