PDA

View Full Version : PRB and throughput



Handover24
2013-05-06, 04:20 AM
Is there a formula to get throughput knowing the PRB used by an UE ?
thanks

topoffenders
2013-05-08, 10:23 AM
Throughput on PRB level?

There is cell or User throughput, an UE can be scheduled more than one PRB.

babak1349
2013-05-08, 02:50 PM
Hello,
To calculate the the throughput in LTE (for example in DL)
1) number of allocated PRB
2) number of Used RE (resource element in PRB) Some RE is used for RS, CCCH and so on So they are not carrying user data
3) MCS (Modulation type and coding rate which is determined based on CQI)

So for a PRB: # REs is 12*7 (during 1 ms) (just ignore the used REs for CCCH and RS)
in each RE a symbol is send and bits/symbol depends on modulation scheme for 64QAM , 16QAM and QPSK it is respectively 6,4,2
The used coding is also affecting your throughput for example the ratio is 2/3

in the end:
PRB throughput (Kbits/s) ~ 12*7*(bits/symbol)*(Coding ratio)
So in the best condition:
PRB throughput (Kbits/s)=168*6*1 ~ 1008 Kbits/s
e RE

Anyway it is not the approach to calculate the capacity as the used RE for user data could be 80~85% of total available REs
Besides there is no independent resource for signaling and so the PRB is used for user signaling and which another overhead to user DATA throughput
hope my comments help you out

Cheers

Is there a formula to get throughput knowing the PRB used by an UE ?
thanks