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what is this technology ma'am ? how are you going behind the ppt?

7:48, wouldn't that be pi and 2*pi? If i=1,2,... and M=2.

where is the matlab files

Thank you very much for your work !

mam thank you very much

Hi and thank you for an excellent explanation of OFDM.I am just beginning to try to understand OFDM and have one ( probably stupid ) question though: Let's say you use some QAM-modulation. In to the IDFT you then have complex numbers from a constellation diagram. Out from the IDFT you have some other complex numbers that are serialized and transmitted. In the receiver, these complex numbers are sampled and fed into the DFT that calculates the original complex numbers from the constellation diagram. The question: If you can send and then detect the complex numbers from the IDFT, why can't you send and detect the complex numbers from the constellation diagram directly ?

I am really loving your lessons. Very clear and intuitive

💐💐💐

Intéressant. Merci

Thank you ❤

really cemented my idea of a random process, thank you very much

Excellent video series. Thank you.

Good stuff

Dear Mrs. Rusch, First of all thank you for this great video. I don‘t know whether you will read this but I have a bit of a problem understanding why 2D-QAM shouldn‘t be possible with just IM/DD. Looking at WiFi QAM demodulation can be performed in DSP. Do I really need the entire phase information on my detected IM-signal when I just need to separate it into inphase and quadrature component which can easily be done by performing a multiplication with sin or cos and filtering it with a lowpass-filter? I understand that coherent detection is neccessary for applications like DPSK but for 2D-QAM IM/DD should just be fine, shouldn‘t it? Looking at literature I found a lot of papers stating the use of QAM-Mapping in e.g. OFDM-applications while using direct detection. Am I missing a point here? Greetings from Germany! Kind regards Flo

Très beau cours. Merci !

I really like your easily understandable teaching! I have a question though, regarding the error rate conversion: Don't we have to take into account the case of multiple bit errors occurring with a single symbol error? Especially as with orthogonal modulation all symbols are equidistant...

hi Leslie, do you think there is a way to obtain the signal phase information in an all-optical way before the photodetection?

Mam, I want to calculate coupling coefficient between two cores or coupling length of a multicore fiber supporting OAM modes. Is it possible to directly copmpute from COMSOL ? Thanks in advance.

Very well explained and I hate Math too LOL

At 13:00, is it an actual physical filter? or is it just modeling the lowpass gain-bandwidth product of a TIA? Thanks

Great channel Pr Rusch

This video is a very straightforward explanation without intimidating mathematical equations.

Merci !!!!

I just found your channel and I really appreciate all the work you put into these. Excellent instruction!

Thanks a lot for clearing my doubts !

So just to be clear, after the serial to parallel conversion (see 15:29) we do quadrature amplitude modulation but this is NOT actually modulation in the traditional sense of circuitry to modulate? It's more of a mapping, correct? Also, to physically transmit the signal do we have to use the same modulation scheme as the one used in the "mapping" stage?

good

Amazing! Thank you very much

Nice

Thanks Mam, very effective lectures in the whole playplist, I am following it to revise the whole course

Thanks Professor

thank you very much

merci beaucoup

merci madame pour ce contenu

omg, finally i get it, thanks!

Thank you so much Professor for uploading videos about CMA! Before this, I couldn't find any content on CMA on TH-cam. Your efforts are greatly appreciated. Could you please consider making a video explaining the mathematics behind CMA? That would be really helpful. Thanks again!

Hi, thank you for awesome video. At 10:27, the fractions inside of Q functions for P_e of BPSK and BFSK looks the same at the end. I think there is a typo for BPSK case.

Great Job! Congrat!

great video

I've been in the business for many years, your teaching methods are awesome.

the link was invalid in the end of the video . Could you please update the link?

Dear Professor, thank you for this detailed explanation. I have 3 questions and would be grateful to get responses from you or recommendations for what to read. 1. Is the modulation at the subcarrier level not actual modulation in the sense of varying some aspect of a wave (phase, amplitude, frequency, etc) to embed information? Is it simply a mapping between data bits and our choice of points on the constellation diagram? 2. From the IFFT module we get complex numbers e.g. a +bi. If we use 64 subcarriers, I understand that we would get 64 time samples i.e. 64 different complex numbers. Now how are these 64 complex numbers combined to form a single symbol to be sent? 3. For the actual transmission, does a (real part) modulate the cosine while b ('imaginary') part modulate the sine? in other words, what is the physical process for going from the complex time samples into physical voltage variations that results in RF emissions. The 5GHz oscillator you mention going to be split into one cosine and another sine (90 degrees out of phase), have these individually modulated and then the modulated sine is combined with the modulated cosine before finally being used to induce voltage changes at the antenna feedpoint..? Merci

I can never thank you enough for uploading your lectures on the public platform for free, they are truly a goldmine. I was failing to understand communication system since first year at varsity, but through watching your lectures im happy and grateful for the comm. systems intuition and understanding that i have gained.

merci madame

This is the explanation I’ve been looking🙌🏾

Best explanation, your lectures are top notch

it is very useful explanation, thank you very much

Thanks for the illustration! But seems that the last four minutes of the video is all black has no audio

Much Appreciated Professor.

I think it's backwards at 9:46. Ergodic is always stationary but not vice versa. Iaian Explains Signals has a nice video showing this.