What is MIMO OFDM?
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- Опубліковано 3 кві 2022
- Explains some of the different versions of MIMO OFDM from a block diagram perspective.
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For a full list of Videos and Summary Sheets, goto: www.iaincollings.com
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OMG, You are going to really take on this challenge. I was right to sub all along when I first saw your episode with frequency shift.
A very complex topic, glad to see yet another great explanation from you
That is the best explanation that I have ever seen! Congratulations!
It will be really great to have transmission Mode session, especially from TM6 to TM9
Very good explanation of a pretty complex topic! Many thanks, Professor!
Thank you for a great job. Your explanation is extraordinary
Thank you professor. Best Channel for Wireless Communications
Nice
Great video! Thanks!
Thank You. In pic 3: What does that beamformer exactly do? It gets one stream -does it gives a phaseshift according to the different antennas so that the amplitudes add coherently?
Thank you professor! I like the video! May I understand this way for pic2 and pic3?
Thanks, I refer to the OFDM Multicarrier Beamforming on the lower left side: how do I have to think about that BF1 operation? We are in the frequency domain, that's clear. So for each subcarrier, we get a point in the IQ plane - that is what I know how we "feed" the IDFT. But how does BF1 now beamforms that point in the frequency domain?
Thank you. I know that you can express amplitude, frequency and phase in this notation : Asin(2pif+phi) - I believe that is the polar notation.
is nice
Thank you, I have a more general question concerning the in- and output of the IDFT.
Hallo, I have a short question. With regard to both pics on the left side. In the lower pic, we can adjust phase and amplitude with these BFs. That is clear. But in the upper picture (OFDM Spacial Multiplexing), how do we adjust phase and phase and amplitude there? I assume we must give something like the channel matrix and then we calculate the precoding matrix to multiply it with the symbol vector - but there seems not to be anything like that in the pic. Thanks a lot.
Thank you professor. Your videos are really helpful. I have one question: in the pictures above, the output of IDFT block is a baseband signal with frequency ranging e.g., 0 - 20 MHz? And these signals must be upconverted to a carrier frequency, e.g., 3GHz for transmission? Is the beamforming operation in the pictures applied to a carrier wave (or a base band signal)? It is really confusing to me, especially when we consider digital beamforming.
Hi, thanks for the video, I have a question. In 4G or NR standards, is each subchannel reserved for a user or we are occupying more than 1 subchannel in our mobile phones? If we are using only one subchannel, is it the motivation to use MIMO-OFDM systems?
To allocate the cases into digital and analog beamforming, is it right that only the 2. image shows analog beamforming? Only there you have the phase-shifters at the end.
Hi professor,