Questions and Comments for
Please post your reviews, comments, and questions below.
- Review by Miguel Castellanos
You have a good mix of derivations/figures and explanations (text), which makes it easy to follow your thought process and is important to explaining the concepts. Your first two figures clearly show how to downsample a signal. Some small mistakes are a convolution symbol in your first derivation that should not be there, your sum for the expression of the DTFT of a downsampled signal should start from 0, and your last figure shows a different cutoff frequency than what you derived. Other than that, nicely done!
- Author answer here
- Review by Michael Hayashi
I like the simple depiction of downsampling in your first two graphs. The LaTeX gets a little out of hand in places. I recommend caution using quotation marks for formatted type and advocate the "math" tags instead. The definition of $ s_D[m] $ should have $ m $ appear in place of $ n $ in the middle expression. It may be beneficial to explain that the $ 2\pi $-periodicity of the downsampled DTFT is maintained through a combination of $ D $-factor reduction of the period coupled with the offset copies introduced by the summation. The motivation for and derivation of the cutoff freqeuncy of the low-pass filter was expressed well. Overall, the content was very good.
- Review by student 3
- Author answer here
- Review by student 4
- Author answer here
