SPD_Huawei ERAN6.0 Power Control Feature Introduction

8/10/2019 SPD_Huawei ERAN6.0 Power Control Feature Introduction

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HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

Huawei Confidential

Security Level:

Huawei eRAN3.0Power Control Feature

Introduction

Zhuxiyun / 00167826







HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential Page 4

Content

Introduction

UPLINK POWER CONTROL

DOWNLINK POWER CONTROL



HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential

UPLINK POWER CONTROL: OVERVIEW

Uplink power control is performed on uplink physical signals, traffic

channels, and control channels. It includes power control for the

following signals and channels:

Physical random access channel (PRACH)

Physical uplink shared channel (PUSCH)

Physical uplink control channel (PUCCH)

Sounding reference signal (SRS)

Page 5




Power Control for the PRACH

CMAX P

)(i PUSCH M

is the maximum allowed transmit power.

is the number of physical resource blocks (PRB) allocated.

is cell/UE specific parameter signaled by radio resource control (RRC).

is the ramping step in power ramping of the preamble.

is the downlink path loss estimate. It is calculated in the UE based on the

reference symbol received power (RSRP). PL = RS - RSRP

is the number of times the UE sends the preamble.

PL

})1(,min{ _ step pre preamble preoCMAX PRACH N PL P P P

preo P

_

}))(log(10,min{ 23 _ O_pre3 msg TF Msg PREAMBLE PUSCH CMAX MSG PL P i M P P

preamble is the offset of the power for the current preamble format against preamble format 0.

pre N

step

3 _ Msg PREAMBLE is the preamble delta value of Msg3.

TF is the offset of the power for the current MCS format against the reference MCS format.

2msg is the TPC command





eNB Initial ly sets PRACH preamble expected

received power

UE estimates dow nl ink path loss

UE sets the PRACH transmit pow er according

eNB parameter and path loss

I f the random access preamble attempt fai ls ,UE

can increase the transmit power for the next RA

preamble attempt

C

eNB

A B

preamble

preamble

preamble

CELL

minimize

transmit

power

ensure therandom access

success rate and

latency




Power Control for the PUSCH

)}()()()log(10,min{ PUSCH _ 0)(maxTX i f PL j j P M P P i PUSCH

MAX P

)(i PUSCH M

0 P




is the path loss compensation factor.



is a closed loop correction value TPC and f is a function that permits to use

accumulate or absolute correction value.

)( j

PL

)(i f

)()()()log(10PHR PUSCH _ 0)(ma x i f PL j j P M P i PUSCH

•Power headroom for the UE

•The closest value in the range [40; -23] dB with steps of 1 dB





When UL power is limited, how to allocate RB

and MCS to achieve better UL throughput？More RB,

lower MCS or few RB, higher MCS?

PHR : Power Headroom Report

PL : Path Loss

TPC : Transmit Power Command

Outer

Loop

Control

Consider PL, RB, QoS, etc.

Compared with PSD

PSD Target

eNodeB UE

PHR

TPC Inner

Loop

Control

NEARPOINT

FARPOINT

MIDPOINT

limiting UE power

reduce RB

Carring all RB,so

easy!

Reduing R

SHARE RB




Power Control for the PUCCH

CMAX P

PUCCH P _ 0


is the receive power expected by the eNodeB.



is determined by the PUCCH format. nCQI is the number of information bits ofthe CQI and nHARQ is the number of information bits of HARQ,

is the current PUCCH power control adjustment state.

PL

)(i g

i g F nnh PL P P i P HARQCQI F_PUCCH0_PUCCHCMAXPUCCH ,,min

HARQCQI nnh ,

)( _ F PUCCH F reflects the transmission format of the PUCCH on the transmit power.

ensure the

PUCCH

performance

ACK/NACK

CQI： RI（Rank Indicator ）

CQI（Channel Quality Indicator ）

PMI（Precoding Matrix Information）

SRI ： Scheduling Request Indication

PUCCH FUNCTION

reduce the

interference to

neighboring

cells




Power Control for the Sounding

Reference Signals

CMAX P

SRS M

pusch P _ 0




is the path loss compensation factor.



is the offset of the SRS power against the PUSCH power.

PL

)(i f

)}()log(10,min{)( _ 0 _ CMAX

i f PL P P M P i P PUSCH OFFSET SRS SRS SRS

I am SRS

Power! I willfollow you

I am PUSCH

Power!

is a closed loop correction value TPC and f is a function that permits to use

accumulate or absolute correction value.

OFFSET SRS P

_




Uplink Power Control formula summary



Power Control for the PUCCH

Power Control for the SRS

})1(,min{ _ step pre preamble preoCMAX PRACH

N PL P P P

}))(log(10,min{23 _ O_pre3 msg TF Msg PREAMBLE PUSCH CMAX MSG

i M PL P P P

)}()log(10)()(,min{)(PUSCH _ 0ma xTX

i f M PL j j P P P i PUSCH

)}()log(10,min{)( _ _ 0CMAX

i f P M PL P P i P OFFSET SRS SRS PUSCH SRS

i g F nnh PL P P i P HARQCQI

F_PUCCH0_PUCCHCMAXPUCCH

,,min





HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 14

Key Parameters Introduction

Id Name Description Recommended

Value

MML

P0NominalPUCCH P0 nominal PUCCH Indicates the target UE transmit power for the

PUCCH expected by the eNodeB on

condition that normal demodulation can be

performed.

-105 LST

CELLULPCCOM

M

PSrsOffsetDeltaMcs

Disable

PSrsOffset when

DeltaMcsEnalbed is

UU_DISABLE

Indicates the power offset of the sounding

reference signal to the PUSCH when

DeltaMcsEnabled is set to UU_DISABLE.

-30 LST

CELLULPCDEDI

C

PassLossCoeff Path loss coefficient Indicates the compensation factor for path

loss. It is used in UL power control.

AL07(0.7) LST

CELLULPCCOM

M

P0NominalPUSCH P0 nominal PUSCH Indicates the nominal P0 value of the PUSCH.

It is used in UL power control.

-67 LST

CELLULPCCOM

M




Feature Relationship Introduction

The uplink power control algorithm provides the uplink scheduling algorithm with the power

headroom for the UE.

The uplink scheduling algorithm provides the uplink power control algorithm with the TBSand the number of allocated RBs, based on which UE power is set. In addition, the uplink

scheduling algorithm provides information such as the PUCCH format and SRS resource

amount for related power setting.

The VoIP semi-persistent scheduling algorithm provides the uplink power control algorithm

with the BLER that is reached in semi-persistent scheduling mode. The BLER is a

prerequisite for enabling PUSCH power adjustment in semi-persistent scheduling.

The random access procedure provides the uplink power control algorithm with information

such as the preamble format and the number of times the UE sends the preamble




Feature Gain Introduction

0

5

10

15

20

25

30

35

40

45

50

90 100 110 120 130

T p u t / m b p s

PL/dB

Single UE, CLPC vs OLPC

CLPC OLPC

CLOSELOOP, keep

RB number

OPENLOOP,RB reduce

quickly




Feature Monitoring Introduction

M2000

PROBE



HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 18 Page 18

Content

Introduction

UPLINK POWER CONTROL

DOWNLINK POWER CONTROL




DOWNLINK POWER CONTROL: OVERVIEW

Downlink power control is achieved using either of thefollowing techniques:Fixed power assignment

Fixed power assignment is applicable to the cell-specific reference signal, synchronization

signal, PBCH, PCFICH, and the PDCCH and PDSCH that carry common information of the cell.

Users configure fixed power based on channel quality. The configured power must meet the

requirements for the downlink coverage of the cell.

Dynamic power control

Dynamic power control is applicable to the PHICH and the PDCCH and PDSCH that carry

dedicated information sent to UEs. Dynamic power control lowers interference, expands cell

capacity, and increases coverage while meeting users' quality of service (QoS) requirements.




Power Allocation for the PDSCH

P A=E A/ERS

ρa = E A

/ERS，ρb = E

B/E

RS

type A :during a symbol period when there

is no reference signal.

type B :during a symbol period when there

are reference signals.




Power Allocation for the PDCCH

eNB

UE#1

UE#2

Large Tx power on PDCCHto control the Bler

convergence the Bler targetSmall Tx power on

PDCCH to control the

Bler convergence the

Bler target

UE#3PDCCH Power and CCE

combined design to improve

the PDCCH capacity and to

control the Bler convergence

the Bler target




Key Parameters Introduction

Id Name Description Recommended Value MML

ReferenceSign

alPwr

Reference signal

power

Indicates the reference signal power of

the cell

None LST PDSCHCFG

PaPcOff PA for even power

distribution

Indicates the PA when the power

control for the PDSCH is disabled, the

downlink ICIC is disabled, and the even

power distribution is used for thePDSCH

Dual-antenna or four-antenna:

-3 dB,Single antenna: 0 dB

LST

CELLDLPCPDSCHP

A

Pb Pb Indicates the scaling factor index of the

Energy Per Resource Element (EPRE)

on the PDSCH. This scaling factor is

determined by the value of this

parameter and the antenna port.

Single-antenna: 0; double-

antenna: 1

LST PDSCHCFG

DlPcAlgoSwitch

Downlink powercontrol algorithm

switch

Indicates the switches used to enable ordisable power control for PDSCH,

PDCCH, and PHICH.

PdschSpsPcSwitch:OffPhichInnerLoopPcSwitch:Off

PdcchPcSwitch: Off (for an

FDD cell) or On (for a TDD

cell)

LSTCELLALGOSWITCH




Feature Relationship Introduction

Downlink power control is depends on downlink scheduling because the downlink

scheduling algorithm provides the downlink power control algorithm with information

such as the PDCCH DCI format, type of information carried on the PDSCH, and QoS of

UEs.

The CQI adjustment algorithm provides the adjusted CQI for the downlink power

control algorithm.

The VoIP semi-persistent scheduling algorithm provides the downlink power control

algorithm with the BLER that is reached in semi-persistent scheduling mode. The

BLER is a prerequisite for enabling PDSCH power adjustment in semi-persistent

scheduling.




Feature Monitoring Introduction

M2000

RRC_SYS_INFO



Thank You

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SPD_Huawei ERAN6.0 Power Control Feature Introduction