Thursday, July 27, 2006

Time Domain Aliasing Cancellation and Perfect Reconstruction

Hey Wait ! Don't run away !!! This post is not going to delve into any sort of technical details. I can understand your shock at seeing such a techie title on this blog. I too had the exact same reaction to the title the first time I read it. I was like, What the #@$% is this ????

I came across this title when I was studying some DSP concepts recently. I realised how much I had forgotten whatever I had studied during engineering. So, reading through those topics got me thinking about the final year of my engineering, where we had taken up a course in Digital Signal Processing (DSP). It was one of those "hyped" courses, where the pass percentage was not very high. Most were paranoid about such courses and many joined tutions for the same. Thankfully, I was not one of them. I still dont understand the logic of joining tutions during engineering. If the lecturer is bad and the textbook does not make any sense, then its kind of understandable. But the lecturer who handled this course was an amazing chap and there is definitely no dearth of good textbooks on DSP. But still, the students joined. Mainly because in the previous batch of students who had taken up this course, many had flunked. I dont understand why students get so influenced by this trend. Can't they think logically ? I have also observed this trend in subjects like "Fields and Waves", "Control Systems" and "Engineering Graphics". Literally, the entire class used to go for tutions for these subjects.

Coming back to what I had originally planned to put up in this post, the lecturer who taught us this course was an amazing chap. He has handled subjects for us in almost all the semesters and that too on different unrelated topics. From "C Programming" to "Operations Reaserch" to "Microprocessors" to "Digital Signal Processing" to "Fields and Waves". And he did justice to all of them. His notes were very much in demand. I still have his notes in most of the courses he taught. And he never used to read out the notes from a previous year's student's notebook. He used to dictate them by himself. Man, I am a huge fan of this lecturer. I happened to meet him about 4-5 months ago and he is still very much the same. Absolutely no change at all.

Apart from our lecturer, I am also so much reminded of my engineering friends. The masti we used to do in college: bunking classes, not listening in class, last minute preparations for exams, internals, results... etc. DSP was one subject we hated to study. We liked the classes and were in awe of the subject, but hated to study it for the exam. So much of fourier transforms in that course. It can be quite intimidating, with all those sigma and integration signs. We all heaved a huge sigh of relief after we finished the exam, which turned to be quite easy :D

Now that I am studying so many of those concepts again, they all seem so easy. I realised that it takes time for the concepts to sink in and I think three years have been more than sufficeint for the same. I am totally enjoying studying this subject now.


shub said...

why the hell are you brushing up your concepts again?

PizzaDude said...

@shub: For offcial purposes :)

Amaunet said...

yeah its really sad to know students in engg take up tuitions...its an insult to a so called "Professional course".
But dont u think when lecturers dictate "Notes" in class at this level, tuitions follow the same course???
I mean cmon when u call tuitions as kiddish or unnecessary for an 18-19 yr old even "Dictation of notes" in class is equally kiddish

Vin said...

I sometimes felt tution would re-iterate whatever was told in the class, so it would sink in....
As I read ur blog, I remember how I hated database concepts. Last minute reading, sleepless nights.

PizzaDude said...

@amaunet: Now that you tell it, you are right..
When someone gives notes, it literally means giving out important points, which can be used for revising or similar purposes.. but in colleges today, dictating notes has translated to "dictating in-detailed explanation about the topic" very much like a text book.

@vin: Yeah, that is what is ideally supposed to happen.. But, I do remember many people joining tutions and not-listening there as well... What's the purpose ? If people are anyway not going to listen, why join tutions ?

Anonymous said...

Dude! The blog u wrote exactly matches my situation now... me too brushing the concepts for job purpose
n u kno landed here searching some technical stuff! :D good work!

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