UL Power Control

4G LTE
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Hi Experts.

What is best value for Path loss coefficient & P0 nominal PUSCH in Huawei LTE to get optimum cell edge user throughput?

Admin note: this post was updated with image below.

fractional power control
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If P0NominalPUSCH is set to a small value, it is recommended that PassLossCoeff be set to a large value to ensure higher data rates for cell edge users (CEUs) (Option 2)

  1. medium to high load scenarios (where intercell interference is more significant)
    PassLossCoeff =AL08(0.8)
    P0NominalPUSCH = -80 dBm

  2. low load scenarios:
    PassLossCoeff = AL1
    P0NominalPUSCH = -106 dBm

below counter can be used to determine whether the uplink interference is reduced:
L.UL.Interference.Avg

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How to calculate the best values for p0NominalPusch and alpha for 4G?

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It is expalined here: LTE Power Control (Case of Uplink Channel : PUSCH) – Tech Trained

You need to get used with fractional power control.

This picture is important:

fractional power control
fractional power control1215×724 89.9 KB

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Thank you very much!

And for NB-IoT, do you think that is the same?

Or the idea of the trade off betwen p0NominaPusch and alpha is diferent?

Because of the energy consumption and the coverage improvement.

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Hello Experts.

In UL power control, which is better Open loop or Closed loop?

Switching between Open loop and closed loop can be adaptive?

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Closed loop.

Depends on the scenario.

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Closed Loop power control is UE oriented mechanism, which means that gNB is trying to optimize the UE Tx power for each UE individually so it can be more optimal and beneficial.

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Open loop power control is performed before the UE is connected to the access network, for RACH channel for example.

Closed loop power control is applied when the UE is in connected mode for PUSCH and PUCCH, because close loop power control requires continuous feedback from the eNB/gNB.

No type is better than the other both are applied at different states of UE.

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Are P0 nominal and alpha used in closed loop or open loop?

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Closed loop.

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Which parameters deal with Open loop in UL?

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Check SIB2, there you will find.

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  • Power Ramping Step (delta)
  • Preamble initial received target power
  • Filtering Coefficient

Sent to UE in SIB 2

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I think in high load scenarios or the cases with high external interference it is better to use OL.

In first case with high number of users it cause excessive interference.

In second case CL could not compensate for external interference.

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Most of the time closed loop is better.

Since the decision will be based on many feedbacks.

Open loops are good for initial connections or when the UE is not aware about the configuration of the network.