Also adjacent constellation points are Gray or Binary coded. One way is to term the bottom leftmost point as say 000000 for 64 QAM and then go Grey coded in Row and Grey coded in Column. The blocks that perform the modulation are normally called Constellation mapper and Constellation demapper.
Hello Sir , hope you are doing fine. i enjoy all your lecture , please include video topics in 5G -NR protocol stacks like RRC/RLC/MAC as well as Log analysis wireshark toll QXDM etc
Nice explanation.. 👍thank you sir … one doubt! MCS decides what type of modulation (say 16 qam, 64 qam , 256 qam etc) required in a cell for the UE depending upon radio channel conditions … what about subcarrier spacings ? Scheduler select only one sub carrier spacing in one cell depend upon cell size . Isn’t ?
Also finally 1/2 means there ae two coding bits for one data bit. This comes from the convolutional encoder in the transmit part. 1/3 means one data bit has been split into 3 coding bits ( 8.33)
QAM256 is only used when the channel allows a high data rate or the Bit error rate is low. If the Channel is poorer - low RSSI the modulation will switch down to QAM64.
Also adjacent constellation points are Gray or Binary coded. One way is to term the bottom
leftmost point as say 000000 for 64 QAM and then go Grey coded in Row and Grey coded in Column. The blocks that perform the modulation are normally called Constellation mapper and Constellation demapper.
Thanks for the explanation
Sir I have queries related to NB-IoT. I am working in a research area. Need your assistance. How can i contact you.
Hi Rasveen. You can contact me on LinkedIn.
Hello Sir , hope you are doing fine. i enjoy all your lecture , please include video topics in 5G -NR protocol stacks like RRC/RLC/MAC as well as Log analysis wireshark toll QXDM etc
Hi Vivek. Sure I will try to add videos on this topic.
nicely explained....Thank you.. :)
Thanks for the feedback :)
Nice explanation.. 👍thank you sir … one doubt! MCS decides what type of modulation (say 16 qam, 64 qam , 256 qam etc) required in a cell for the UE depending upon radio channel conditions … what about subcarrier spacings ? Scheduler select only one sub carrier spacing in one cell depend upon cell size . Isn’t ?
Subscriber spacing is usually kept the same for entire network
Also finally 1/2 means there ae two coding bits for one data bit. This comes from the convolutional encoder in the transmit part.
1/3 means one data bit has been split into 3 coding bits ( 8.33)
Yes in terms of coding that is correct
Its not X axis and Y axis when you talk about QAM its always I and Q.
That said this is a good video.
Sorry for over-simplification for some of the users :)
Great👏
Thanks for the positive feedback
Great video , thanks...One note from my side, LTE (LTE-Advanced) has 256 QAM as well but the percentage of 256 QAM is very less...
Yes have corrected in the description. Thanks
QAM256 is only used when the channel allows a high data rate or the Bit error rate is low. If the Channel is poorer - low RSSI the modulation will switch down to QAM64.
nice
Thanks.