Questions and Comments for Frequency Domain View of Upsampling

A slecture by exchange student from UNAM, Mexico, Michel Olvera.



Please post your reviews, comments, and questions below.



  • Review by Miguel Castellanos

Your introduction gives a great preview of the concepts that you cover in your slecture. I also like how you included some practical examples, which are a great way to relate the course material to real-world applications. A small discussion about aliasing would be nice to see since this is always a concern when dealing with DT signals. Excellent job!


  • Review by Yerkebulan Y.

In Introduction, I think, you should provide graphs to show how you inserted zero-valued samples. Good explanation of  using LPF  graphically, which was not in the lecture notes. Some minor spelling errors. At the end you listed very interesting practical application of upsampling like in audio signals and images.


  • Review by Sahil Sanghani

This was a good slecture. I agree with some of the reviews above. I think you should make some graphs to demonstrate the interposed zeroes. Otherwise the other concepts were demonstrated and explained well with the graphs. I think that including an explanation of the various cases where aliasing can occur. I enjoyed the practical application portion of the slecture. It shows the usefulness of the content.


  • Review by Andrew Pawling

Very good slecture. The material is very clear and concise. I really liked the practical examples and really help readers better understand upsampling. The plots are very nice and easy to interpret. Good job!


  • Review by David Klouda

You incorporated the template perfectly with the appropriate amount of space allocated to each section. I liked how you kept the theory section simple and did not complicate it by over-deriving it as I have seen in a few other slectures.


  • Review by Soonho Kwon

It would have been better to illustrate how the zero padding works. Other than that, I loved your introduction, which literally explains most of the topic. Also, your example and conclusion part was also very clear to understand. Great job.


  • Review by Botao Chen

Good job first! As other reviews say. Graph will be much more helpful to show your point. You did have very good explanation about how to use low pass filter when doing upsampling. In the end, the practical example is very good to have a deep understanding about the upsampling.


  • Review by Hyungsuk Kim

I thought that this slecture is great. Every basic concept about upsampling is well explained in introduction. And example of upsampling is well explained in graphically. However I think you should make LPF gain of 2 as you written in the block diagram.


  • Review by Yijun Han

The work is very clear and easy to follow. The introduction is concise and clearly states the process of upsampling. The practical examples are great to mention the applications using upsampling. Good job.


  • Review by Fabian Faes

I really enjoyed the use of the block diagrams and the following graphs which I feel made the explanations very clear to follow and understand. The overall flow of the slecture is natural with the division of the different sections. I specifically enjoyed the practical uses listed in upsampling as it makes it easier to relate it to the real world and give it a meaning. The reference list also seems very well researched and gives strong credentials to the slecture. Great job!


  • Review by Xian Zhang

I really like your slecture. The text following after the graph makes everything really connective. I have a better understanding of the material.


  • Review by Michael Hayashi

I consider this to be a very good slecture. I feel that it could be improved a bit by including a more formal introduction of $ s_D[n] $ and the explicit relationship between the sampling periods of the original sampling ($ T_1 $) and the new sampling rate ($ T_2 $). The graphs of the interpolator working and the examples provide good motivation for this slecture, which is often lacking in other students' explanatory works.


  • Review by Randall Cochran

This is a great slecture. The introduction did a great job of explaining the concepts you were going to show later. The only things that could be added is a graphical representation showing the inserted zeros concept, and some more detail on s(mD), such as more clarity on the part where you say, but s(mD) = 1. Really good slecture though.


  • Review by Chloe Kauffman

I think you could have added some more detail describing the relationship between D and T, and that x(n) is a sampled bandlimited CT signal sampled above Nyquist. The graphs are very clear and aid in the explanation.
Overall, very good slecture.


  • Review by Ryan Johnson

I really like the graphs you used to explain your work. I would put more effort into the conclusion as you did not use the complete sentence and makes the reader question your expertise on the subject matter.


  • Review by Matt Miller

The diagrams found in this diagrams are excellent and explain the content well however the theory sections could use more detailed explanations.


  • Review by Robert Stein

I probably would have included a time-domain representation of the function in the introduction. Other than that great job on everything.


  • Review by student 18

Author enter here.


  • Review by student 19

Author enter here.


  • Review by student 20

Author enter here.


  • Review by Evan Stockrahm

The series of plots is great if you already have a decent understanding of upsampling, but I would like to see a little more explanation of the plots. Well done overall though.


  • Review by student 22

Author enter here.


  • Review by student 23

Author enter here.


  • Review by student 24

Author enter here.


  • Review by student 25

Author enter here.


  • Review by student 26

Author enter here.


  • Review by student 27

Author enter here.


  • Review by student 28

Author enter here.


  • Review by student 29

Author enter here.


  • Review by student 30

Author enter here.


Back to ECE438, Fall 2014

Alumni Liaison

Have a piece of advice for Purdue students? Share it through Rhea!

Alumni Liaison