Questions and Comments for Frequency domain view of the relationship between a signal and a sampling of that signal

A slecture by ECE student Botao Chen

Partly based on the ECE438 Fall 2014 lecture material of Prof. Mireille Boutin.



Please post your reviews, comments, and questions below.



  • Review by Miguel Castellanos

You have a great organization of your derivations and examples. Your first derivation helps ease the transition between continuous sampled signals and discrete sampled signals. The figures are good graphical represenations of the expressions you derive. A small source of confusion is that your final figure plots a function in terms of ω but your x-axis is in terms of f. Great job, overall!


  • Review by Yerkebulan Y.

You gave very good explanation of difference between FT of original signal x(t), sampled signal  xs(t) and discrete signal xd[n]. Graphs in frequency domain  help to understand this difference. You did a really good job !


  • Review by Andrew Pawling

The mathematical derivations are great! The plots work and help illustrate the difference. The last plot needs to be labeled with $ \omega $ on the x-axis instead of $ f $, so that was a little confusing. But other than that, good job!


  • Review by David Klouda

I really liked your slecture. I would recommend re-sizing the graphs as they are relatively simple and do not need to be that large to convey the meaning of the graph.


  • Review by Sahil Sanghani

The explanations are great. I like the clarifications that you included in your derivation. The derivation was also very clear. As mentioned above, the last plot is labeled wrong, but otherwise this was a great slecture.


  • Review by Fabian Faes

The overall flow and layout of this slecture are great and easy to follow. I particularly enjoyed the thorough explanations and formulas accompanied by the graphs which really solidify the idea. The use of color in the graphs is always a good thing since it really highlights the idea that is talked about.


  • Review by Chloe Kauffman

The only thing I would have added is to use the phrase "ideal sampling" when referring to the Xs(f). Also, I don't think it was ever specified that your example assumes a bandlimited signal with max frequency fm. Lastly, tying in the concept of aliasing would have been a nice bonus, since your graphs are very clear. Overall, this slecture was very useful and helpful for me to ready through.


  • Review by Ryan Johnson

I really liked how you illustrated the changes the frequency axis goes through in the Fourier transform. I think this is a really important concept which you illustrated clearly.


  • Review by Evan Stockrahm

Good job displaying the change in periodicity. I would like to have seen a graph of the sampling though from beginning to end.


  • Review by Matt Miller

The content was explained very clearly however the formatting of the diagrams could be improved.


  • Review by Robert Stein

Nice job. The concept was really clear. I think the graphs could have been sharper and/or formatted better, but other than that good job.


  • Review by student 12

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  • Review by student 13

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  • Review by student 14

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  • Review by student 15

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