gongdori
Full Member level 2
Hello,
I am a DSP newbie and have question about downsampling after Hilbert transform.
I have a real signal coming into the system and i am going to use Hilbert transform FIR filter to make analytic signal.
Then, since I have only one sided spectrum, I am going to down sample it by 2.
And, here is the question.
I thought I always need to move the spectrum to the baseband before I decimate it. But, I've heard that the location of the spectrum is not important as long as the bandwidth of the spectrum is within the Nyquist criterion... And that puzzled me.
If we have a spectrum which starts from 0 and ends at fs/2 and if we downsample it by 2, how come we don't get any aliasing from the spectrum from fs/4 to fs/2? Aren't they going to be overlapped on the top of the spectrum from 0 to fs/4?
Thanks
Thomas
I am a DSP newbie and have question about downsampling after Hilbert transform.
I have a real signal coming into the system and i am going to use Hilbert transform FIR filter to make analytic signal.
Then, since I have only one sided spectrum, I am going to down sample it by 2.
And, here is the question.
I thought I always need to move the spectrum to the baseband before I decimate it. But, I've heard that the location of the spectrum is not important as long as the bandwidth of the spectrum is within the Nyquist criterion... And that puzzled me.
If we have a spectrum which starts from 0 and ends at fs/2 and if we downsample it by 2, how come we don't get any aliasing from the spectrum from fs/4 to fs/2? Aren't they going to be overlapped on the top of the spectrum from 0 to fs/4?
Thanks
Thomas