LTE Physical Layer
ฝัง
- เผยแพร่เมื่อ 5 ก.ค. 2024
- This video talks about LTE Physical Layer and LTE Air Interface. It has explained following topics in the same order as given below:
1. OFDMA
2. LTE frame structure (FDD and TDD)
3. LTE resource grid (Resource Block, Resource Element)
4. Calculation of slot duration
5. Calculation of downlink data rate
6. Downlink physical signals (Reference Signals and Synchronization Signals)
7. SC-FDMA
Very good tutorial.
A few minor corrections on 'Calculation of Slot Duration' at 15:20
4.6 ms -> 0.46 ms
5 * 144 -> 6 * 144
1/(1500*2048) -> 1/(15000*2048)
Excellent!!! One of the best explanations seen so far in a very concise and easy to understand way.. Wish there were a video series on 5G from you..
Great Work and Well explained the physical layer of LTE system.
Amazing, very well organized, and easy to understand. It helped me to pack up al the LTE theory comprehension. I struggled with the accent a little bit though. I missed very few words. It would be great if a text script can be added to the video. Thank you very much again.
well explained, I wants to say thank you..........Good job......
Thank you for this informative session!
appreciate your job.well done .
Excellent -Thanks for sharing
Great video.
Would like to see something regarding HSPA
Would like to see something regarding frequency band allocations.
Thank you for working so hard on your English Language Diction. It really makes a big difference.
Thank you for not over-using the word 'provide'. It also makes a big difference.
Thanks a lot Torf for the feedback!!! Actually, I started this channel only few months back. After covering LTE, I will move to UMTS RAT.
Your feedback help me improve. can you tell me by diction what do you mean - clear pronunciation or selection of words while speaking.
I did not get your last line regarding usage of "provide". Please explain a bit more.
great work dude :)
Very helpful and detailed......
wonderful, thanks
really awesome explanation
Hi Thanks for the excellent explanation,I have one doubt regarding the PSS and SSS signals.During the cell search procedure ,how UE understands that the last symbol of slot 1 and 10 is PSS and the preceeding value would be SSS,is it like these sequences would be pre storrd in UE?
Very helpful...Thanks
hello thanks for ur video. Can you please how these RBs' are distributed in 3 sectors of enodeb..
Very helpful, could you please share the slides
Its vry good presentation.. which tools you use for animation...is it your voice???...very clear voice....
thank you..very well explained..pl. do more videos
excellent video...keep it up
Thanks for the good job
Thank you its very clear and rich
thanks a lot!!!
Nice tutorial.
Hi.
First of all, congratulations for the series of videos! It has been helping me a lot!
I have some doubts:
Each timeslot is occupied by one single Ue, right?
These timeslots are the resource blocks?
If each Ue transmits/receives its information through a timeslot, it means that the Ues are allocated in a TDMA basis in the radio frame, right? If so, we can conclude that each radio frame can support the maximum of 20 Ues. Is it correct?
Thanks a lot!
+Gustavo Troiano +Gustavo Troiano
No, one time slot can have data for multiple UEs. One time slot just represents a fix duration on time axis. But on frequency axis there could be multiple sub carriers available in the system during a time slot. eNodeB can assign these different carriers to different mobiles during a time slot.
Think from resource element point of view. eNodeB can assign different resource elements to different UEs in a given timeslot.
Note: At a given time one resource element can be assigned only to one UE.
Ok. I got it.
Thanks again.
No of Bits in Subframe while calculating the data speed , will it be subframe or for the entire BW of 20 MHZ ? Please correct me if I am wrong . Else the explanations are awesome
Thanks
Pratik
Excellent
It seems no one explains how uplink stream head (i.e. frame timing) is decided. In the case of downlink the baseband generates the stream and defines frame start readily but uplink will receive a stream from radio. How is that stream aligned to frame structure. This will have major impact on TA measurements.
Very good Video to learn LTE Basics
Thanks Ashutosh!
Looking for standard definition of naming convention of primitive messages, 1. REQUEST is it from lower layer to higher layer only ? 2. Response 3. CMD 4. IND etc ..any specs defining it, rules etc
Corrections: At 14:23, OFDM symbol duration = 1/15KHz = 66.67us
Short CP duration = 144*Ts = 4.6875us
At 15:20, Tslot = (7* OFDM symbol duration) + (First Short CP Duration) + (6* Short CP Duration)
= 7*66.67e-6 + 160*Ts + 6*4.6875e-6 = 5e-4 = 0.5ms.
Thank you
please create your blog as well so that can be read in lesser time
Slot duration calculation @[14:53] should be 0.46msec instead of 4.6 msec? right?
V good video to understand LTE concept even experienced guys. and my request is help to understand UE measurement , L3 messages with Drive logs if possible.
Thanks for this genuine feedback. Log analysis video is there at least for UE attach. Please go to my channel and watch the video. For other topics please wait...:)
Thanks for the good job, but here shall be a typo.. OFDM symbol duration will be "66.67 usec"
Nice 👍
I have a question whether there is a format of 4G PHY header?
the Final Slot Duration at (15:32) it should be 6 short cyclic prefix (144) + 1 extended CP (160). isn't ?
I was expecting more details about SC-FDMA..
@15:26
the time slot is 0.46 msec or 4.6 m sec
nice vdeo
CAN U PLZ UPLOAD THE VIDEO O PHYSICAL CHANNELS
Hi, It looks your other videos regarding LTE attach, CSFB all have been deleted.
Actually, last month TH-cam by mistake suspended my channel. They reinstated it yesterday. You should be able to see all the videos now. Please check again.
LTE Video Tutorials ,your videos have been very helpful for an amateur like me. Thanks keep it up !
The OFDM symbol duration is 6.67 us or 66.7 us????
66.7us
Could you check your time slot calculation again I think it is wrong because you used 1500 instead of 15000 when calculating 7 cp time duration.
Hi Neel, calculations are correct. But I made few typo mistakes while putting values in the formula. I have corrected these mistakes now in video by putting necessary speech bubble. Thanks a lot for pointing this out!
I think, I need a proofreader now :)
When did X (TIMES) become INTO? I think INTO means DIVIDE?
:)
Like 5gnr
hello again
Very Difficult
Excellent
Thank you