zte umts power control-20090302

7/28/2019 ZTE UMTS Power Control-20090302

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ZXWR RNC

Power Control


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Content

Uplink Open Loop Power Control

Downlink Open Loop Power Control

Uplink Inner Loop Power Control

Downlink Inner Loop Power Control

HSDPA Power Control


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Uplink Open Loop Power Control


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Uplink Open Loop Power Control - PRACH

Purpose: Estimate the initial transmit power of physical channels such as

PRACH, DPCCH and DPDCH, and mainly refers to determining the PRACH

transmit power.

PRACH Initial Transmit Power:

Preamble_Initial_Power = Primary CPICH DL TX power CPICH_RSCP

+UL interference + Constant Value

- Primary CPICH DL TX power: transmit power of P-CPICH which isbroadcasted in SIB5 or SIB6.

- CPICH_RSCP: the channel code power of CPICH measured by UE.

- UL interference: uplink interference, which is measured by NodeB and

updated in real time in SIB7.

- Constant Value (ConstVal): related with the cell environment and theservice rate on PRACH, broadcasted in SIB5 or SIB6.

If Preamble_Initial_Power > MaxRACHTxPwr, Preamble_Initial_Power =

MaxRACHTxPwr.


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Uplink Open Loop Power Control - PRACH

If Preamble_Initial_Power > MaxRACHTxPwr, Preamble_Initial_Power =

MaxRACHTxPwr.

If no response (+1 or -1) of AICH is received after the first PRACH

preamble composed, UE selects a new signature in the next timeslot.

Increases the preamble transmit power by Power Ramp Step (PRStep).

The transmit power of the control part of PRACH message is:

PRACH_C_Power = Preamble_Initial_Power+sum(PowerRampStep)+Pp-m

- Pp-m(POPpm): power offset between the control channel and the last

PRACH preamble which is related to the PRACH message TFC.- Similar to uplink DPDCH and DPCCH, the power of the PRACH

message control part and data part is controlled by the gain factorc and

d.


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Uplink Open Loop Power Control - DPCCH & DPDCH

ccc

cd d

Scode

I+jQ

DPCCH

DPDCH I

S

2

)(d

c

DPDCH

DPCCH

P

P


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Uplink Open Loop Power Control - DPCCH

Uplink DPCH Open Loop Power Control mainly determine the initial

transmit power of DPCCH, and the gain factorc and d of the uplink

DPCCH and DPDCH.

DPCCH_Initial_power = DPCCH_Power_offset - CPICH_RSCP

DPCCH_Power_offset = Eb/N0+ (NT+IT) PG + CPICH_TX_Power

- Eb/No: quality factor of the DPCCH PILOT domain (DpcchPilotEbN0).

- NT+IT: uplink interference, measured by NodeB updated in SIB7.

- PG: Processing Gain, which equals to the DPCCH Spreading Factor 256.

c and d are set fixed value according to the TFC.


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Downlink Open Loop Power Control


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Downlink Open Loop Power Control Common Physical Channels

Downlink common physical channels transmit power and parameters:

AichPwrAICH

PichPwrPICH

MaxFachPwrFACHSCCPCH

PchPwrPCHSCCPCH

BchPwrP-CCPCH

PcpichPwrP-CPICH

SschPwrS-SCH

PschPwrP-SCH

Channel Parameter Default

-7dB(0.4w)

-7dB(0.4w)

-1dB(1.6w)

-3dB(1w)

-3dB(1w)

33dBm(2w)

-4dB(0.79w)

-3dB (1w)

%

4.5%

10%

0.39%

0.5%

Activation Ratio

10%

10%

10%

10%

90%

100%

10%

10%

0.5%

0.8%

0.2%

0.2%


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Downlink Open Loop Power Control P-SCH Power

Primary Synchronization Channel and Secondary Synchronization

Channel are used in cell search procedure;

Cell search procedure includes:- Slot synchronization

- Frame synchronization and acquire the scrambling code group number

- Identify the Primary Scrambling Code

- P1: P-SCH transmit power- P2: S-SCH transmit power

- P3: P-CPICH transmit power

- PTOT: Maximum downlink transmit power (MAXDlTxPwr)

- PI : Total received power from other cells

- PR: Total received power from serving cells- P-SCH load factor: P1/(P1+P2)

- SCH load factor: (P1+P2)/ PTOT- P-CPICH load factor: P3/ PTOT- Geological factor G: PR / PI, (-6,6)dB, -6dB means cell border


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Downlink Open Loop Power Control P-SCH & S-SCH Power

0

500

1000

1500

2000

2500

3000

5.00% 7.50% 10.00% 12.50% 15.00%

ms initial search

= 0.5, = 0.1, G = -3

Vs cell search time

initial

search

15.0% 43.35 ms

12.5% 57.46 ms

10.0% 96.27 ms

7.5% 297.3ms

5.0% 2476 ms

- The initial cell search time increases greatly when

is less than 10%but changes little when is larger than 10%.- The larger the is, the less power the other downlink physical channel

can use.


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Downlink Open Loop Power Control P-SCH & S-SCH Power

initial search

0.5 96.27 ms

0.55 82.23 ms

0.6 74.47 ms

0.65 69.63 ms

0.7 67.18 ms

0.75 68.41 ms

= 0.1, = 0.1, G = -3

Vs cell search time

- The initial cell search time decreases when the P-SCH power increases.- The second step of cell search (Frame synchronization) is more efficientthan the first step (Slot synchronization), so takes the value around 0.6.

0

20

40

60

80

100

120

50.00% 55.00% 60.00% 65.00% 70.00%

ms

initial search


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Downlink Open Loop Power Control P-CPICH Power

initial search

12.5% 96.15 ms

10% 96.27 ms

7.5% 108.13 ms

5% 155.79 ms

2.5 1462.5 ms

= 0.5 = 0.1, G = -3

Vs cell search time

- The initial cell search time increases greatly when is less than 5% but

changes little when is larger than 10%.- P-CPICH is used to do channel estimation, so 10% is recommended.

0

200

400

600

800

1000

1200

1400

1600

2.50% 5.00% 7.50% 10.00% 12.50%

ms initial search


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Downlink Open Loop Power Control P-CCPCH Power

Simulation results of

The Impact of CellSearch on System

Performance in

WCDMA from IEEE.

The simulation settingsof ETSI Vehicular A

environment are listed in

the right table.

Sectors/site 3

Site to site distance [m] 6000Log-normal fading std [dB] 10

Correlation distance [m] 28.85

Speed [km/h] 120

Handover margin [dB] 3

Maximum active set size 2

Maximum power for one TCH [W] 1

Maximum BS power for all TCH [W] 18

Power for CPICH [W] 1

Required Eb/No [dB] 7.9

Processing gain [dB] 26.8


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Downlink Transport Channel C/I Vs SCH+P-CCPCH power

The best value ofSCH+PCCPCH

power is 0.5w

which is -3dB

compare to the P-

CPICH power

setting in thesimulation

environment


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Downlink Transport Channel C/I Vs P-SCH/P-CCPCH power

The acceptablerange of P-SCH/P-

CCPCH is [-10,0]dB,

ZTE takes the value

of 0dB which is -3dB

compare to the P-

CPICH power settingin the simulation

environment.

.


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Downlink Open Loop Power Control S-CCPCH

S-CCPCH carries PCH and FACH;

There is no inner loop power control for the S-CCPCH, so the

maximum power of S-CCPCH is configured.

S-CCPCH carrying PCH uses SF128 code. Test results of paging

shows the paging failure ratio does not change much when the PCH

power takes the value of -3dB, -1dB and 0dB. So the default value is -

3dB.

S-CCPCH which carries FACH uses SF64 code, the maximum power

is -1dB and the transmit power is changed according the TFC of FACH.


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Downlink Open Loop Power Control DPCH

Determine the initial DPCH transmit power;

totaltxcpichc

CPICHtxreq

b

inittx P

N

E

P

PG

NE

P ,

0

,0

,

- PG: Processing Gain

- Ptx,CPICH: P-CPICH transmit power- Ec-cpich/N0: CPICH Ec/N0(dB) reported by UE- : Orthogonal Factor, 0.5

- Eb/No: Eb/No of the service configured corresponding to the current

rate of the access service.


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Downlink Open Loop Power Control DPCH

Traffic Class Data Rate Downlink Traffic Eb/N0 (dB)

Conversational DL WAMR6.60k~23.85k 7.5

Conversational DL 64K(PS Conversational Video) 5.2

Conversational DL NAMR4.75k~12.2k 7.5

Streaming PS64k 1.7

Streaming PS384k 0.9

Streaming PS128k 0.9

Streaming CS64k 1.7

Interactive PS8k 6.9



Interactive PS128k 4.5Background PS8k 6.9

Background PS64k 1.7




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The specifications define following inner loop power control:

- Receiver measures the SIR (Eb/No) of each radio link and compare

with the target SIR (SIRtarget) which is set fixedly according to theservice type.

- If SIR>= SIRtarget, Receiver sends a TPC command 0 to Transmitter;

- If SIR< SIRtarget, Receiver sends a TPC command 1 to Transmitter;

- Transmitter changes the transmit power according to the TPC

command value. The delta value is TPC_cmd*TPC_STEP_SIZE(TpcStepSize).


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The specification 25.214 defines two uplink inner loop power control

method which is configured by parameterUlIlPcAlgin OMCR.

- Algorithm 1: the UE transmit power can be adjusted every timeslot,and transmit power can be increased or decreased.

- Algorithm 2: UE transmit power is adjusted every five timeslots, and

transmit power can be increased, decreased or not changed.

Current Parameters Configuration:- Algorithm 1 tracks the fluctuating of channel better than Algorithm 2.

- According to the network deployment now (Feb, 2009), there is no

continuous coverage (no macro-diversity gain) and only one carrier (no

load balancing), Algorithm 1 is recommended.


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UTRAN adjusts the current downlink powerP(k-1) to the new transmit

powerP(k) according to the following formula:

P(k) = P(k- 1) + PTPC(k) + Pbal(k)

- PTPC(k): the kth power adjustment value;

- Pbal(k): correction value to balance the power of radio links.


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Two downlink inner loop power control method can be configured by

parameterDPCMode in OMCR:

- Mode 1: UE sends a TPC command at each timeslot. The UTRANadjusts the transmit power at each timeslot according to the TPC

command.

- Mode 2: UE sends the same TPC command for three timeslots. The

UTRAN adjusts the transmit power once every three timeslots

according to the TPC command.

The step to adjust the downlink transmit power is configured by

parameterTpcDlStep.

Current Parameters Configuration:

- Mode 1 tracks the fluctuating of channel better than Mode 2.

- According to the network deployment now (Feb, 2009), there is no

continuous coverage (no macro-diversity gain) and only one carrier (no

load balancing), Mode1 is recommended.


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HSDPA Power Control


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HSDPA Power Control HSDPA total power alloction

Free allocation of NodeB

- The total power used by HSDPA (HS-SCCH & HS-PDSCH) shall not

exceed [Maximum cell power - downlink transmit R99 power (including

common physical channels power)];

- In each TTI, NodeB reports the TSSI (Transmitted Signal Strength

Indicator),

R99 power = TSSI HSDPA used power

- In the next TTI, the available HSDPA power is:

HSDPA total power = Maximum cell power - R99 power


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HSDPA Power Control HS-SCCH power setting

NodeB determines the HS-SCCH power according to the CQI-

based outer loop power control algorithm

Pdelta)/(9)/s( hs hspdschscchCPICHHSSCCH NoEsNoEPP

PCPICH: Refers to the receive power of pilot channel (Unit: dBm).

(Es/No)hsscch is constantly 1.2dB.

: refers to the MPO (MeasPwrOffset).

(Es/No)hspdsch = -4.5 + CQI dB; Pdelta: the value obtained based on HS-SCCH BLER outer loop

adjustment.


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HSDPA Power Control Measurement Power Offset (MPO)

UE shall assume a total received HS-PDSCH power:

- the total received power is evenly distributed among the HS-PDSCH

codes of the reported CQI value

- the measurement power offset is signaled by higher layers

- the reference power adjustment is given by specifications

CPICHHSPDSCH PP

In case that the number of HS-SCCH is 2, simulation shows:

- the highest cell throughput is achieved when MPO=6dB;

- the average scheduled UE number falls down when MPO exceeds

7dB.

- the average HS-PDSCH number scheduled falls down when MPOexceeds 6dB.

The default value of MPO is 6dB


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HSDPA Power Control Measurement Power Offset (MPO)

Items Settings Items Settings

Running Time for Simulation 10 secondsAverage number of user

per cell

10

Inter-site Distance 2000m Category of user 8

Number of Cells 21 Mean acceleration of UE 0

Path Loss Model 128.2+37.6log[d(km)] Flow Controller YES

Shadowing fading model

Lognormal fading

Standard Dev 8dB Scheduler PF

Max Transmit Power 41.2dBm Max retransmission No. 3

Power of CPICH 31.2dBmCombination of

retransmissionCC

Number of HS-SCCH 2 Receiver Rake

Power control of HS-SCCH Based on CQI Number of HS-DSCH 14

Max power of each HS-SCCH 0.5W Power of HSDPA 65%

Min power of each HS-SCCH 0.02W Channel model PA3

Number of HARQ processes 8 Orthogonality factor 0.6


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HSDPA Power Control Measurement Power Offset MPO)

Average Cell Throughput Vs MPO

the highest cell throughput is achieved when MPO=6dB


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Average Scheduled User No. Vs MPO

the average scheduled UE number falls down when MPO exceeds 7dB

Average Scheduled User No.

0

1

2

3

3 4 5 6 7 8 9 MPO


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Scheduled HS-PDSCH No. Vs MPO

average scheduled UE number falls down when MPO exceeds 7dB

Scheduled HS-PDSCH No.

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

3 4 5 6 7 8 9 MPO


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Parameters


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Power Control Parameters - ConstVal

Parameter name PRACH Initiation Tx Power Constant Value(dB)

Abbreviated name ConstVal

DescriptionThis parameter is the correction value when calculating

the initial transmission power of PRACH preamble.

Range and Step [-35, -10]dB step 1dB

Unit dB

Default Value

(note)-18dB


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Power Control Parameters - PRStep

Parameter name PRACH Preamble Power Ramp Step(dB)

Abbreviatedname

PRStep

Description

This parameter indicates the power ramp step used by

the UE when it does not receive any responses from

AICH after sending a preamble. This parameter is usedto be added to the previous power, and then the next

preamble is sent at this new power.

Range and Step [1, 8]dB step 1dB

Unit dB

Default Value

(note)1dB


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Power Control Parameters - POPpm

Parameter

name

Power Offset between PRACH Control Part and PRACH

Data Part

Abbreviated

namePOPpm[MAX_ PRACH _TFC]

Description

This parameter indicates the power offset between control

part of the PRACH message part and the last preamble. It

should be configured for each TFC. WhereMAX_PRACH_TFC=32.

Range and

Step-510dB step 1dB

Unit dB

Default Value

(note)22


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Power Control Parameters - DpcchPilotEbN0

Parameter name DPCCH Pilot Field Eb/N0(dB)

Abbreviated name DpcchPilotEbN0

Description

This parameter indicates the quality factor of the UL

DPCCH PILOT domain which is a constant used for

calculating the UL DPCCH power offset for a newly

accessed call.

Range and Step[-30, +30]dB

step 0.1dB

Unit dB

Default Value (note) Next slide

C


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Conversational UL 3.4kbps Signaling(AM): 3dB Background UL PS 64kbps: 3dB

Conversational UL AMR 6.60~23.85kbps: 3dB Background UL PS 384kbps: 5dB

Conversational UL 64kbps (PS Conversational Video): 3dB Background UL PS 128kbps: 3dB

Conversational UL NAMR 4.75~12.2kbps: 3dB Interactive UL PS 1024kbps: 5dB

Conversational UL CS 28.8kbps: 3dB Interactive UL PS 2.048Mbps: 5dB

Conversational UL CS 32kbps: 2dB Interactive UL PS 3. 072Mbps: 5dB

Conversational UL CS 64kbps: 3dB Interactive UL PS 4.096Mbps: 5dB

Streaming UL CS 14.4kbps: 3dB Interactive UL PS 5.76Mbps: 5dB

Streaming UL CS 28.8kbps: 3dB Background UL PS 1024kbps: 5dB

Streaming UL CS 57.6kbps: 3dB Background UL PS 2.048Mbps: 5dB

Streaming UL CS 64kbps: 3dB Background UL PS 3. 072Mbps: 5dB

Streaming UL PS 64kbps: 3dB Background UL PS 4.096Mbps: 5dB

Streaming UL PS 384kbps: 5dB Background UL PS 5.76Mbps: 5dB

Streaming UL PS 128kbps: 3dB Streaming UL PS 1024kbps: 5dB

Interactive UL PS 64kbps: 3dB Streaming UL PS 2.048Mbps: 5dB

Interactive UL PS 384kbps: 5dB Streaming UL PS 3. 072Mbps: 5dB

Interactive UL PS 128kbps: 3dB Streaming UL PS 4.096Mbps: 5dB

Streaming UL PS 5.76Mbps: 5dB

Power Control Parameters - DpcchPilotEbN0


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Power Control Parameters - PschPwr

Parameter name Primary SCH Power(dB)

Abbreviated

namePschPwr

DescriptionPSCH transmission power. This parameter is the offset

relative to PCPICH power.

Range and Step [-35, +15]dB step 0.1dB

Unit dB

Default Value

(note)-3dB


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Power Control Parameters - SschPwr

Parameter name Secondary SCH Power(dB)

Abbreviated name SschPwr

DescriptionSSCH transmission power. This parameter is the offset

relative to PCPICH power.

Range and Step [-35, +15] dB step 0.1dB

Unit dB

Default Value

(note)-4dB


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Power Control Parameters - PcpichPwr

Parameter name P-CPICH Power(dBm)

Abbreviated name PcpichPwr

Description

This parameter indicates the transmission power level

of the Primary CPICH (Common Pilot Channel), which

is an absolute value.

Range and Step [-10.0, 50.0]dBm step 0.1dBm

Unit dBm

Default Value

(note)33.0dBm


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Power Control Parameters - PchPwr

Parameter name PCH Power(dB)

Abbreviated name PchPwr

Description

This parameter indicates the transmission power of the

PCH mapped on the SCCPCH, which is a power offset

relative to the PCPICH power.

Range and Step [-35, 15]dB step 0.1dB

Unit dB

Default Value

(note)-3dB


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Power Control Parameters - MaxFachPwr

Parameter name Maximum FACH Power(dB)

Abbreviated name MaxFachPwr

Description

This parameter indicates the maximum transmission

power of the FACH which is mapped on the SCCPCH.

This parameter is the relative value based on thePCPICH transmission power.

Range and Step [-35, 15]dB step 0.1 dB

Unit dB

Default Value

(note)-1dB


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Power Control Parameters - AichPwr

Parameter name AICH Power(dB)

Abbreviated name AichPwr

DescriptionThis parameter indicates the AICH transmission power,

which is an offset relative to the Primary CPICH power.

Range and Step [-22, 5]dB step 1dB

Unit dB

Default Value

(note)-7dB

P C l P T S Si


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Power Control Parameters -TpcStepSize

Parameter name TPC Step Size (dB)

Abbreviated name TpcStepSize

Description

This parameter indicates the TPC step size for uplink

inner loop power control. Only when inner loop power

conrol algorithm 1 is selected, this parameter needs tobe configured. For algorithm 2, default value of TPC

step size is 1 and this parameter is not needed.

Range and Step 1dB, 2dB

Unit dB

Default Value

(note)1dB

P C t l P t UlIlP Al


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Power Control Parameters -UlIlPcAlg

Parameter name Uplink Inner Loop Power Control Algorithm

Abbreviated

name UlIlPcAlg

Description

This parameter indicates which uplink inner loop power

control algorithm is used. For algorithm 1 inner loop

power control is done every time slot. For algorithm 2

inner loop power control is done every 5 tim slots.

Range and Step1: Algorithm 1

2: Algorithm 2

Unit N/A

Default Value

(note)1: Algorithm 1

P C t l P t DPCM d


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Power Control Parameters - DPCMode

Parameter name DPC Mode

Abbreviated

name DPCMode

Description

This parameter indicates which downlink inner loop

power control algorithm is used. There are two kinks of

downlink inner power control algorithm: single TPC and

TPC triplet in soft. And which algorithm to be used

should be configured to UE.

Range and Step0: Single TPC

1: TPC Triplet in Soft

Unit N/A

Default Value

(note)0: Single TPC

P C t l P t T DlSt


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Power Control Parameters - TpcDlStep

Parameter

nameTPC DL Step Size(dB)

Abbreviated

nameTpcDlStep

Description

This parameter indicates downlink inner loop power control

adjustment step length. Usually with stable channel condition,

this value is small; in worse radio environment, this value is

larger.

Range and

Step0.5 1 1.5 2dB

Unit dB

Default Value

(note)1dB

P C t l P t M P Off t


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Power Control Parameters - MeasPwrOffset

Parameter name HS-PDSCH Measurement Power Offset(dB)

Abbreviated name MeasPwrOffset

Description

This parameter indicates the assumed HS-PDSCH

power offset relative to P-CPICH/S-CPICH power used

for CQI measurement.

Range and Step [-6, 13]dB step 0.5 dB

Unit dB

Default Value

(note)6

P C t l P t Li t


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Power Control Parameters List

Name Default Value TRUE Value

ConstVal -18dB -18dB

PRStep 1dB 1dBPOPpm [2, 2]dB [2, 2]dB

DpcchPilotEbN0 slide 35 slide 35

PschPwr -3dB -3dB

SschPwr -4dB -4dB

PcpichPwr 33.0dBm 33.0dBm

ScpichPwr 0dB 0dB

BchPwr -3dB -3dB

PchPwr -3dB -3dB

MaxFachPwr -1dB -1dB

PichPwr -7dB -7dB

AichPwr -7dB -7dB

TpcStepSize 1dB 1dB

UlIlPcAlg 1: Algorithm 1 1: Algorithm 1

DPCMode 0: Single TPC 0: Single TPC

TpcDlStep 1dB 1dB

MeasPwrOffset 6dB 6dB


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zte umts power control-20090302

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