@@pauldenisowski Thank you so much for this gold video regarding constellation diagram interpretation, Please, what about symbol rotations in the constellation diagram for QAM-OFDM? what is the reason? it is related to the channel? Thank you so much for your response and help :)
@@bstanis1237 Phase noise (unlike "normal" noise) is normally due to imperfections in the transmitter and/or receiver, not in the channel. Hope that helps!
Great to watch a video renewing my memory on a topic, i wrote an FPGA implementation years ago for (simulating hardware impairments in real-time). Great refresher! Thanks
Thanks, point well taken - I appreciate precision in language :) I assume you're referring to slide 3 ("Carrier shifted between discrete states "). Since the carrier always moves from one state to one another state, I used "between" in this case. I would absolutely agree with "among" when there is not a direct motion between states: e.g. "during demodulation, the receiver must choose from among these discrete states" Again, many thanks!
But most modern communication system uses OFDM in which the I/Q value are put on the subcarrier. Therefore, most of conclusions in this video are no more valid.
Constellation diagrams are also used in OFDM-based communications systems. In fact, in some of our other videos you can see constellation diagrams created from 5GNR and 802.11ac signals (both OFDM-based technologies) ua-cam.com/video/_dZhxmgT1bE/v-deo.html ua-cam.com/video/su0orD9E7Nk/v-deo.html You make a good point regarding OFDM in that each subcarrier is individually modulated, so the creation of constellations from the recovered, per-subcarrier IQ values is somewhat more complicated than in non-multicarrier systems. But constellation diagrams and the methods by which they are interpreted still apply in OFDM-based systems as well.
Detailed and clear explanation. Thank you.
Thanks for the feedback!
Thank you for a clear and understandable presentation of the information.
Thanks for the feedback!
@@pauldenisowski Thank you so much for this gold video regarding constellation diagram interpretation,
Please, what about symbol rotations in the constellation diagram for QAM-OFDM? what is the reason?
it is related to the channel?
Thank you so much for your response and help :)
@@bstanis1237 Symbol rotation in constellations is almost always due to phase noise (frequency instability).
@@pauldenisowski Thank you so much, but phase noise is related to the used channel? or what is the original of this issue?
@@bstanis1237 Phase noise (unlike "normal" noise) is normally due to imperfections in the transmitter and/or receiver, not in the channel. Hope that helps!
Great video, had much fun seeing it!
Thank you!
Amazingly explained 👍
Thank you for the clear explanation!
Great to watch a video renewing my memory on a topic, i wrote an FPGA implementation years ago for (simulating hardware impairments in real-time). Great refresher! Thanks
thank you so much for such a great explanation
Thanks for the feedback!
thank you!! you are awesome
Thank you..I am in love
Thanks!
Between is typically used when referring to two things, like "between a rock and a hard place," while among is used for a greater number.
Thanks, point well taken - I appreciate precision in language :) I assume you're referring to slide 3 ("Carrier shifted between discrete states
"). Since the carrier always moves from one state to one another state, I used "between" in this case.
I would absolutely agree with "among" when there is not a direct motion between states: e.g. "during demodulation, the receiver must choose from among these discrete states"
Again, many thanks!
But most modern communication system uses OFDM in which the I/Q value are put on the subcarrier. Therefore, most of conclusions in this video are no more valid.
Constellation diagrams are also used in OFDM-based communications systems. In fact, in some of our other videos you can see constellation diagrams created from 5GNR and 802.11ac signals (both OFDM-based technologies)
ua-cam.com/video/_dZhxmgT1bE/v-deo.html
ua-cam.com/video/su0orD9E7Nk/v-deo.html
You make a good point regarding OFDM in that each subcarrier is individually modulated, so the creation of constellations from the recovered, per-subcarrier IQ values is somewhat more complicated than in non-multicarrier systems. But constellation diagrams and the methods by which they are interpreted still apply in OFDM-based systems as well.
The video links seems to be not working. Can you please share them again? Thank you. Great Video by the way.