3 LTE ERAN6.0 Power Control Feature ISSUE1.00

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LTE eRAN6.0 Power Contr ol Feature

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Objectives 

Upon completion of this course, you will be able to:    

Describe the object of power control in LTE Describe the strategy and parameters of DL power control Describe the strategy and parameters of UL power control Monitor power control result from M2000

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Contents 1. 2. 3. 4.

Power Control Overview Downlink Power Allocation Uplink Power Control Feature Activate Observation

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Purpose of Power Control





Compensate path loss , including shadow fading and multiple path fading Reduce interference on the edge cell

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Power Control Features in eNodeB 

Downlink power control: 



There is no uplink power control command, so DL power cont rol is more like dynamic power allocation

Uplink power control 

Including open loop, closed loop and inner loop power contro l. 1 bit or 2 bits power control command is defined for closed loop and inner loop power control

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Strategy for Algorithm

Algorithm

Strategy Reason

PHICH dynamic power adjustment

Disabled

PHICH carry HARQ feedback which requires high accuracy, and default power could guarantee it. And it is not necessary to reduce PHICH power because it occupies very less resource.

PDCCH dynamic Enabled power adjustment

To reduce the service drop rate and increase the throughput for CEUs.

PDSCH dynamic power adjustment

Disabled

Turning on this switch may waste RB resources in multi-UE scenarios. This will bring negative gains to cell throughput and increase overall interference on the entire network.

All uplink power control

Enabled

Reduce UE power as low as possible Improve performance for cell edge user

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Contents 1. 2. 3. 4.

Power Control Overview Downlink Power Allocation Uplink Power Control Feature Activate Observation

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DL Power Distribution Total DL Power Fixed allocation RS PSS+SSS

Dynamic or fixed allocation PHICH PDCCH (Dedicate UE scheduling)

PBCH PCFICH

PDSCH(Dedicated UE data)

PDCCH (SIBs/Paging/RA response scheduling PDSCH (SIBs/Paging/RA rsponse) Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved. Page10

Cell Specific RS Power Setting

Type A Symbol: without RS REs

  

Type B Symbol: RS REs

EPRE: Energy Per Resource Element The RS power setting is based on EPRE RS power is the reference power for the other channel

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Cell Specific RS Power Setting (Cont.) 3/4 　 3/4 　

compensate

compensate



1 　 1 　 1 X 　 3/4 1 　 　 3/4 1 　 　 1 R 　 3/4 1 　 　 3/4 1 　 　 1 X 　 P3/4 b=21 , 　 　 3/4 1 　 　 1 R 　

1 　 1 　 1 　 1 　 1 　 1 　 1 　 1 　 1 　 21 　 1 　 1 　

　 　 　 　 　 　 　 　 　

X

Bandwidt h

PB

PRS ( dBm)

10M

1

18.2

15M

1

16.4

20M

1

15.2

　 　

　 　 　 　 　 　 　 　 　

R

Pb

　 　

Symbol B/ Symbol A 1 ANT port

2 or 4 ANT ports

0

1

5/4

　 　 　 　

1

4/5

1

　

　 　

2

3/5

3/4

Antennas 　 　 　 　

3

2/5

1/2

　 　 　 　

X

　 　 power 　 RS Power ＝ 　Total per channel(dbm) – 10lg(total su 　

R

　 　

bcarrier)+10lg(Pb + 1)

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Synchronization Signal Power Setting



PowerSCH ＝ ReferenceSignalPwr +SchPwr

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PBCH/PCFICH Power Setting



PowerPBCH ＝ ReferenceSignalPwr + PbchPwr



PowerPCFICH ＝ ReferenceSignalPwr + PcfichPwr

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PDCCH/PDSCH Power Setting 

In the following two status, the power for PDCCH and PDSC H power is fixed setting 



When PDCCH carry scheduling information of common contr ol information (RACH response /paging/SIBs indicator ) When PDSCH carry the common info (RACH response/SIB/pag ing message)

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Power Allocation Setting

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Dynamic Power Allocation - PHICH CQI Report

Estimate SINR_RS

Compare it with target SINR_RS



Adjust PHICH power The PHICH occupies very few resources, which means decreasing its tr

ansmit power cannot significantly reduce power consumption. In addit ion, the PHICH carries the ACK/NACK messages for the uplink data, whi ch requires high accuracy. Decreasing the transmit power of the PHICH may reduce accuracy and uplink data rate. Therefore, the dynamic pow er allocation is not recommended in commercial network. Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved. Page17

Dynamic Power Control - PDCCH Off

PDCCH dynamic power control switch On

eNB measure BLER _

Set PDCCH with fixed power

+

Target BLER

>0

Result

Decrease Power

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