Uplink Throughput (Bit Rate) for LTE FDD (coding rate = 1)

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For LTE in case of Downlink, Physical Downlink Control Channel (PDCCH) is the spokes- person of the eNodeB meaning it contains all information related to control region in the Dowlink and Uplink Scheduling related information etc. 



For Uplink the channel which carries control signaling in the Uplink is Physical Uplink Control Channel (PUCCH) . 



Now that the objective of PUCCH is clear. In order to derive the maximum physical layer throughput semi-theoretically (for comparison purposes alone) we need to exclude the affect of the overheads generated by the following:

  • Physical Random Access Channel (PRACH)
  • Demodulation Reference signals
  • Sounding Reference Signals (SRS) 
  • Etc.  

Including PUCCH in Throughput Computation

PUCCH can occupy up 2, 4, 6 or 8 Resource Blocks (RBs) per time slot for all the bandwidths except 1.4 MHz  because 1.4 MHz can only have 6 resource blocks in frequency domain. 


Uplink throughput (normal cyclic prefix)

The throughput values shown below assume that there is NO overheads of PRACH, or sounding reference signal etc. occupying the any resources in Uplink Radio frame. Another assumption is that we have coding rate = 1. Meaning that physical layer has not introduced any redundancy. 

Normal Cyclic Prefix: Maximum Physical layer throughput you can expect on PUSCH for coding rate = 1, no re-transmissions, no PRACH or SRS overheads. Credits: LTE in Bullets

As you may notice in the table above. The maximum Uplink throughput achievable in case of normal cyclic prefix is 84.7 Mbps, whereas for Downlink the maximum throughput achievable for normal cyclic prefix case is 100.8 Mbps  (not shown in the table above, because that table is for Uplink only)

Uplink throughput (EXTENDED cyclic prefix)

Extended Cyclic Prefix : Maximum Physical layer throughput you can expect on PUSCH for coding rate = 1, no re-transmissions, no PRACH or SRS overheads. Credits: LTE in Bullets

The Uplink Throughput Above is for Extended Cyclic Prefix. The assumptions in throughput computation are the same as as for normal cyclic prefix. The only thing that changes here is the concept that in case of extended cyclic prefix, we have less number of Single Carrier - FDMA (SC-FDMA) symbols compared to normal cyclic prefix in 1 msec subframe.

 Therefore, overall throughput turns out to be less as well as shown above. The maximum throughput which is achievable in case of extended cyclic prefix is 70.6 Mbps

Conclusion

The throughput values you see above are for estimation purposes only. You will not see these throughput values being achieved in industry practice. Because the assumptions during this throughput computation are not applicable in real network. 

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