microsoft powerpoint - oeo106030 lte eran6.0 power control feature issue1

LTE eRAN3.0 Power Control Feature

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Spreading Without Permission 1

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Copyright © 2013 Huawei Technologies Co., Ltd. All rights reserved.



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

� Implement the command for the parameters modidicaiton

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Contents

1. Power control overview

2. Downlink power control feature and parameters

3. Uplink power control feature and parameters

Page2


Why Power Control in LTE

� Compensate path loss , including shadow fading and multiple

path fading

� Reduce interference on the edge cell

Page3





Classification of Power Control

� According to the direction, power control is performed both

on downlink and uplink

Downlink power control Uplink power control

Cell-specific reference signalSounding RS

Synchronization signal

PBCHPRACH

PCFICH

PDSCH PUSCH

PDCCHPUCCH

PHICH

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Contents




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DL Power Distribution

Total DL Power

Fixed setting Dynamic power control or fixed setting

RS

PSS+SSS

PBCH

PCFICH

PDCCH (SIBs/Paging/RA response scheduling

PDSCH (SIBs/Paging/RA rsponse)

PHICH

PDCCH (Dedicate UE scheduling)

PDSCH(Dedicated UE data)

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Cell Specific RS Power Setting

� EPRE: Energy Per Resource Element

� The power setting is based on EPRE

Type A Symbol: without RS REs Type B Symbol: RS REs

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Cell Specific RS Power Setting (Cont.)

� RS Power ＝ Total power per channel(dBm) – 10lg(total

subcarrier)+10lg(PB + 1)

Bandwidth PB PRS ( dBm)

10M 1 18.2

15M 1 16.4

20M 1 15.2

3/4 1 13/4 1 1X 1 1 X3/4 1 13/4 1 1R 1 1 R3/4 1 13/4 1 1X 1 1 X3/4 1 13/4 1 1R 1 1 RPB=2 , 2 Antennas

compensate

compensate

PB Power of type B symbol / Power of type

A Symbol

1 ANT port 2 or 4 ANT ports

0 1 5/4

1 4/5 1

2 3/5 3/4

3 2/5 1/2

2 antennas, 20w per antenna

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Synchronization Signal Power Setting

� PowerSCH＝ ReferenceSignalPwr +SchPwr

Radio Frame

Slots

0 1 2 3 4 5 6

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Bandwidth

72

Subcarriers

PSS (Primary Synchronization

Sequence)

Repeated in

slots 0 and 10

SSS (Secondary

Synchronization Sequence)

0 1 2 3 4 5

Bandwidth

62 Subcarriers

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PBCH/PCFICH Power Setting

� PowerPBCH＝ReferenceSignalPwr + PbchPwr

� PowerPCFICH＝ ReferenceSignalPwr + PcfichPwr

Page10


PDCCH/PDSCH Power Setting

� In the following two status, the power for PDCCH and

PDSCH power is fixed setting

� When PDCCH carry scheduling information of common control

information (RACH response /paging indicator )

� When PDSCH carry the common info (RACH

response/SIB/paging message)

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Dynamic Power Control - PHICH

� A high probability of the UE incorrectly demodulating the

PHICH will severely affect user throughput. Power control

ensures the performance of the PHICH for all UEs while

meeting the requirements for the BER.

Estimate SINR_RS

Compare it with target SINR_RS

Adjust PHICH power

CQI Report

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Dynamic Power Control - PDCCHPDCCH dynamic power control switch

Off

Set PDCCH with fixed power

eNB measure BLER

Target BLER+

_

On

Result>0 <0

Decrease Power Increase Power

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PDSCH Power Presentation

Symbol

PPDSCH_A (power of symbol type A on PDSCH) ＝ ρA + ReferenceSignalPwr

PPDSCH_B (power of symbol type B on PDSCH) ＝ ρB + ReferenceSignalPwr

PA = ρA

PB = ρB / ρA

X XR RX XR Rsymbol type A on PDSCH

Su

b_

ca

rriers

symbol type B on PDSCH

Power control for the PDSCH is performed to determine PA for each UE.

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PDSCH Power Control Mechanism

Switch Setting Power Control Mechanism

DlIcicStaticSwitch: ON: or DlIcicDynamicSwitch:ON

Dynamic power control is disabled. PDSCH power is fixed setting respectively for the

Center User (CCU) and Cell Edge User (CEU).

DlIcicSwitch: OFF orDlIcicReuse3Switch:ON

andPdschPaAdjSwitch: ON

Dynamic Power control is applicable for PDSCH

DlIcicSwitch_OFF_ENUM orDlIcicReuse3Switch:ON and

PdschPaAdjSwitch: OFF

PDSCH power is fixed setting

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PDSCH Power Control - Dynamic

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Contents




Page17





PRACH Open Loop Power Control

ensure the random

access success

rate and latency

Minimize the

transmit power

Preamble A

Preamble B

Preamble C

eNB Initially sets PRACH preamble

expected received power

UE estimates downlink path loss

UE sets the PRACH transmit

power according eNB parameter

and path loss

If the random access preamble

attempt fails ,UE can increase the

transmit power for the next RA

preamble attempt

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PRACH Power Control

� The purpose of power control for the PRACH is to ensure the

random access success rate while minimizing transmit power

� The PRACH power is calculated using the following formula:

})1(,min{ _ stepprepreamblepreoCMAXPRACH NPLPPP ∆⋅−+∆++=

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Related Parameters

� MOD RACHCFG

� MOD CELLULPCDEDIC

Page20


PUSCH Power Control Overview

� The purposes of power control for the PUSCH are as

follows:

� Lower interference to neighboring cells and increasing cell

throughput

� Ensure services rates for users on cell edges

� the transmit power for the PUSCH is calculated using the

following formula:

)}()())(log(10,min{)( _ ifiPLPiMPiP TFPUSCHoPUSCHCMAXPUSCH +∆+⋅++= α

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PUSCH Initial Power Determination

� The purposes of power control for the PUSCH are as

follows:

� Lower interference to neighboring cells and increasing cell

throughput

� Ensure services rates for users on cell edges

� The transmit power for the PUSCH is calculated using the

following formula:

)}()())(log(10,min{)( _ ifiPLPiMPiP TFPUSCHoPUSCHCMAXPUSCH +∆+⋅++= α

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Inner Loop Power Control- Dynamic Scheduling Service

� Inner loop

� Adjust TPC according to the transmit power density

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Closed Loop Power Control – Semi-static

� Closed loop

� Adjust TPC according to the IBLER

Page24


Related Commands

� Algorithm Switch

� Initial power setting

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Msg3 Power Control

� When the PUSCH carries Msg3, the transmit power of each

UE's PUSCH is calculated using the following formula:

)}()())(log(10,min{)( 3_O_pre ifiPLPiMPiP TFMsgPREAMBLEPUSCHCMAXPUSCH +∆++∆++=

Page26


PUCCH Power Control

� The PUCCH carries the ACK/NACK information, CQIs, and

schedule request (SR) information related to downlink data. When

the probability of incorrect demodulation on the PUCCH is high,

user throughput is severely affected.

� The purposes of power control for the PUCCH are to ensure the

PUCCH performance and reduce the interference to neighboring

cells.

� The transmit power for the PUCCH is calculated using the

following formula:

( ) )}()(,nh,min{)( _CQI_0 igFnPLPPiP PUCCHFHARQPUCCHCMAXPUCCH +∆+++=

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Inner Loop Power Control

� Inner loop

� Adjust TPC according to the SINR

Page28


Related Commands � Algorithm Switch

� Initial power setting

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Sounding RS Power Control

� The SRS is used for uplink channel estimation and uplink

timing. Power control for the SRS improves the precision in

uplink channel estimation and uplink timing.

� The SRS power is calculated using the following formula:

)}()log(10,min{)( _0_CMAX ifPLPPMPiP PUSCHOFFSETSRSSRSSRS +⋅+++= α

The same as PUSCH Power Control

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microsoft powerpoint - oeo106030 lte eran6.0 power control feature issue1

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