What is SC-FDMA? And why is it used for the Uplink of 4G/5G Mobile?

[@fifaham]

So much going under the hood inside the wireless digital communication devices. Todays modern mobile phones maybe used for few days or less on single battery charge streaming voice, data and image over the air.

[@iain_explains]

Yes indeed. It's amazing to think how complex modern digital electronics is.

[@kkjihuu]

Excellent video. What is different between SC-FDMA and DFT-S-OFDM?

[@iain_explains]

Nothing.

[@Julia-hu4xe]

Thanks, don you have a video about FFT-Beamforming? I cannot find here.

[@Verbatino]

Excellent explanation. One thing I have always wanted to know is the actual energy efficiency numbers for reducing the amplifier for the uplink. In the sense of how much energy can we save under specific radio conditions....🤔

[@jasminnadic2103]

Thanks. A short point regarding a general topic. When I do carrier aggregation in a modern mobile communication network, aren't there any problems with the different propagation characteristics of higher and lower frequencies? Are there limitations what I can aggregate and transmit?

[@iain_explains]

Carrier aggregation is the process of splitting a high rate data stream into multiple low rate data streams and then sending them on seperate carriers (frequency bands), as if they were independent data streams, and then recombining the data streams at the receiver. The propagation characteristics of the separate data streams do not affect each other.

[@pitmaler4439]

Thanks for all of your videos. Although you have a video about OFDM-MIMO, perhaps you cover the terms FD-Beamforming and TD-Beamforming.

[@iain_explains]

Thanks for the suggestion, I'll add that topic to my "to do" list. I currently only cover the standard (time delay, TD) beamformer in "What is Beamforming?" kzbin.info/www/bejne/d2LRZnuerNmtbZo

[@geneschroedertech7501]

If the DFT outputs for a particular user are mapped to a block of OFDM subcarriers, rather than interleaving them, does the intuitive explanation for low PAPR still apply in some way?

[@iain_explains]

The short answer is yes. I said in the video that I would be putting out another video that shows all the mathematical details, but I haven't got around to it yet, sorry.

[@geneschroedertech7501]

Excellent video. It is my understanding that another disadvantage of SC-FDMA is that you can't easily interleave reference symbols with data in the same OFDM symbol (i.e. on different subcarriers). The result is a higher percentage of resources are used for reference symbols with SC-FDMA. It this a significant issue?

[@iain_explains]

Yes, that's right. Channel estimation is easier when training symbols can occupy their own seperate subchannels.

[@vsk5391]

Excellent video. Sir can u make one video about working ofPLL and frequency synthesizers, and their applications in communication systems like in FM demodulation. ❤

[@iain_explains]

Thanks for the suggestion. It's on my "to do" list.

[@bkquanvu3228]

can you explain detail(mathematical) how the signal in SC-FDMA is bounded Peak to Average Ratio?. thanks!!!!

[@the5gguru]

Thanks very much Professor!

[@iain_explains]

You're welcome.

[@mustaphasadok3172]

Thank you professor. As usual a great explanation. Very interested to more details and recommended reading.

[@iain_explains]

Thanks. I'm glad you like the videos. I don't have a "reading list" handy for this topic, sorry. Another thing for my "to do" list.

[@XinHeYT]

The same channel was used . Why access by OFDM method will encounter PAPR while ZF won’t ?

[@iain_explains]

Have you seen my video on PAPR in OFDM? "What is PAPR? and its relationship to OFDM" kzbin.info/www/bejne/fGWvco2KmdKSmJo

[@XinHeYT]

@@iain_explains Yes I did , sir , the carrier pile up in a period of time . If we could made the carrier band width infinitely small , then the PAPR issue will vanished ?

[@iain_explains]

No, the opposite. If there was only one carrier (ie. standard direct carrier modulation) then there wouldn't be a PAPR problem. The more sub-carriers there are, the more chance of having a PAPR problem.

[@TurbidSugar19]

True is, there no enough computation power for all Users in the Base Station either. Did anyone use sc-ofdma in 5G, or its nice legacy from LTE? I see benefit for IoT scenario and everything, but price of base station is much more important