Sampling Signals: Introduction Lecture

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Iain Explains Signals, Systems, and Digital Comms

Күн бұрын

Пікірлер: 23

@andrus3125 Жыл бұрын

Thank you, Professor Iain. I finally began to understand the intuitive explanation of mathematical conclusions, which are limited to our lecturers at the university.

@iain_explains Жыл бұрын

I'm glad it helped.

@rmohnishkumaran Жыл бұрын

Many thanks Prof. Iain. Your easy-to-grasp lectures clarified my understanding of wireless communication at a fundamental level. I work on Wireless Performance at Apple now :)

@iain_explains Жыл бұрын

That's great to hear. I'm so glad you've found the videos helpful. All the best for your career with Apple. I'm sure it's exciting.

@rmohnishkumaran Жыл бұрын

Super challenging but hey - I always have your videos to revise

@stringstoparadise2392 Жыл бұрын

missing your pen and paper sir 😊 any of video is as amazing as it was earlier 👍👍

@iain_explains Жыл бұрын

Yes, I agree, it's better with the pen and paper, and my hands pointing to the important stuff. This video is a version of what I call an audio-book. It's my hand written "lecture notes" with an audio track that plays when the pages turn. I was pretty happy with my explanations on this one, so thought I'd turn it into a video - rather than have to redo it all in the pen-and-paper mode.

@tompang5296 Жыл бұрын

I remember seeing this lecture in person last year! A quick question - what if a signal had a DTFT that was sampled EXACTLY at the Nyquist Rate? Presumably there would still be aliasing, but only on the very highest frequency?

@iain_explains Жыл бұрын

I think what you're trying to ask is: "What happens at _exactly_ the Nyquist frequency?". The answer is that there is actually nothing at _any_ _exact_ frequency. If that sounds counter-intuitive, then perhaps this video will help: "What are the Units of the Fourier Transform?" kzfaq.info/get/bejne/r5x0ntJ9m9isd2Q.html

@lucidasser7153 Жыл бұрын

Thanks a lot for all these videos. In modern mobile communication systems, is there still this frequency plan with Hexagons to avoid interference? You hear seldom about such plans in 5G or LTE.

@iain_explains Жыл бұрын

Yes, cells are still laid out with non-overlapping coverage, in general. However in LTE and 5G there are transmission modes that exploit overlapping coverage where it exists, such as COMP, and also there are hybrid/heterogeneous deployments with small cells "inside" larger cells.

@stephensu4371 Жыл бұрын

nice, i remember when my signal system prof. told me that sampling must be at least twice of the original signal, 2.2 preciously.

@iain_explains Жыл бұрын

I'm glad you liked the video, and that it brought back some memories. 😁

@stephensu4371 Жыл бұрын

@@iain_explains hello Iain, just before i do anything, i am ask for the permission of “may i translate your video and share on bilibili please?”

@zombiekiller404 Жыл бұрын

A future video topic can be on Linear, Memoryless, and casual systems

@iain_explains Жыл бұрын

Thanks for the suggestion. I have one on LTI systems: "What is a Linear Time Invariant (LTI) System?" kzfaq.info/get/bejne/a7BzqNSdqt64pqM.html

@jasminnadic2103 Жыл бұрын

Thanks, what is the difference when you write X(f), instead of X(jw)? Thanks.

@iain_explains Жыл бұрын

Good question. Firstly, w=2pi f , so that's just a scaling. And this video should help to explain where the complex variable j comes into it: "Transform Notation" kzfaq.info/get/bejne/r55hgpyrmtfScnk.html

@stephensu4371 Жыл бұрын

they are equivalent basically, w (omega in lower case) = 2 *pi* f, which is same as saying 60mile and 100km

@jasminnadic2103 Жыл бұрын

@@iain_explains thanks, I have watched it. With the relation w=f*2*pi, one can also write X(f*2*pi)=..... ? (Obviously, one leave "2*pi" away.)

@iain_explains Жыл бұрын

Yes, that's right.