10 RA4121AEN10GLA1 Power Control

Power Control

Power Control LTE Radio Parameters RL10

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Power Control

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Nokia Siemens Networks Academy Legal notice Intellectual Property Rights All copyrights copyrights and intellectual intellectual property property rights for Nokia Nokia Siemens Networks Networks training documentation, documentation, product documentation and slide presentation material, all of which are forthwith known as Nokia Siemens Networks training material, are the exclusive property of Nokia Siemens Networks. Nokia Siemens Networks owns the rights to copying, modification, translation, adaptation or derivatives including any improvements or developments. Nokia Siemens Networks has the sole right to copy, distribute, amend, modify, develop, license, sublicense, sublicense, sell, transfer and assign the N okia Siemens Networks training material. Individuals Individuals can use the Nokia Siemens Networks training material for their own personal self-development only, those same individuals cannot subsequently pass on that same Intellectual Property to others without the prior written agreement of Nokia Siemens Networks. The Nokia Siemens Networks training material cannot be used outside of an agreed Nokia Siemens Networks training session for development development of groups without the prior written agreement of Nokia Siemens Networks.

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Contents 1. LTE Functionalities and Overview 2. Channel Configuration 3. General parameter DB structure and System Information Broadcast

4. Random Access 5. Radio Admission Control (RAC) 6. Radio Bearer Control & DRX /DTX Management 7. LTE Mobility Management Management 8. UL/DL Scheduler 9. MIMO Mode Control (MIMO-MC) 10.Power Control

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Module Objectives After completing this module, the participant should be able to:

• Understand the basics of LTE PC • Describe UL open loop PC part • Discuss UL closed loop PC part (LTE 28) • Identify DL power settings • Analyze PSD • Explain PC impacts on network performance • Distinguish related parameters.

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PSD: Power Spectral Density

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Module Contents • Overview • UL-PC: Overview • UL-PC: PUSCH • UL-PC: PUCCH •UL-PC: Control Scheme • UL-PC: Closed Loop • UL-PC: Parameters • DL-PC: RL10 • DL-PC: PC on PDCCH

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Overview Objective Improve cell edge behaviour, reduce inter-cell interference and power consumption.

DL ‘semi-static’ power setting • eNodeB gives fixed power density per PRB scheduled for transport. – Total Tx power is max. when all PRBs are scheduled – No adaptive/dynamic power control – (O&M parameter) Cell Power Reduction level CELL_PWR_RED [0...10] dB attenuation in 0.1 dB steps – DL PC on PDCCH

dlCellPwrRed Reduction of DL Tx power; deducted from max. antenna TX power. LNCEL; 0..10; 0.1; 0 dB

UL: Slow uplink Power Control • Combination of open loop PC and closed loop PC • Open loop PC – Calculated at the UE based on pathloss measurements • Closed loop PC – Based on exchange of feedback data and commands between UE and eNodeB – SW-licensed enhancement ( can be switched on and off) Improve cell edge behaviour, reduce inter-cell interference & power consumption 6


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Overview Procedure for Slow UL Power control • UE controls the Tx power to keep the transmitted power spectral density (PSD) constant independent of the allocated transmit bandwidth (#PRBs)

• If no feedback from eNodeB ( in the PDCCH UL PC command) the UE performs open loop PC based on path loss measurements

• If feedback from eNodeB the UE corrects the PSD when receiving PC commands from eNodeB ( in the PDCCH UL PC command)  PC commands ( up and down) based on UL quality and signal level measurements

• Applied separately for PUSCH, PUCCH • Scope of UL PC is UE level ( performed separately for each UE in a cell) 2) SINR measurment 3) Setting new power offset

4) TX power level adjustment with the new offset 1) Initial TX power level

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Module Contents • Overview • UL-PC: Overview • UL-PC: PUSCH • UL-PC: PUCCH • UL-PC: Control Scheme • UL-PC: Closed Loop • UL-PC: Parameters • DL-PC: RL10 • DL-PC: PC on PDCCH

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UL-PC: Overview LTE: orthogonal UL tx, i.e. near-far-problem much less severe than WCDMA  • UL: dynamic, slow PC – open & closed loop • need for PL / shadowing etc. compensation  OL PC • need for correction/ adjustments of e.g. open loop inaccuracies  CL PC Signal strength S: depends on PL, indoor loss etc., i.e. location

V e r y l o w

Interference (I) - main cause: inter-cell

Low

High

V e ry h ig h

Noise (N) = kB T ∆f + NFeNB

Power control does not control the absolute UE Tx. power but the Power Spectral Density (PSD), power per Hz, for a device. The PSDs at the eNodeB from different users have to be close to each other so the receiver doesn’t work over a large range of powers. Different data rates mean different tx bandwidths so the absolute Tx power of the UE will also change. PC makes that the PSD is constant independently of the tx bandwidth 9


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UL-PC: PUSCH P PUSCH(i) = min { P MAX,10 log10 ( M PUSCH(i)) + P O_PUSCH( j) + α ( j ) ⋅ PL + ∆TF (i) + f (i)} [dBm] PH ( i ) = P MAX − 10 log 10 ( M PUSCH ( i )) + P O_PUSCH ( j ) + α ⋅ PL + ∆ TF ( i ) + f ( i )

[dB ]

PPUSCH (i) :PUSCH Power in subframe i Pmax: max. allowed power (23 dBm for class 3) MPUSCH: number of scheduled RBs (The UE Tx. Power increases proportionally to # of PRBs) PO_PUSCH(j) = PO_NOMINAL_PUSCH (j) + PO_UE_PUSCH (j)

PL: pathloss [dB] = referenceSignalPower – higher layer filtered RSRP ∆TF

(i) = 10 log 10 (2MPR Ks – 1) for Ks = 1.25 else 0, MPR = TBS/N RE, NRE : number of RE

Ks defined by deltaMCS-Enabled , UE specific Semi-persistant: j=0 / dynamic scheduling: j=1 (RL09: semi-persistant n/a) PO_NOMINAL_PUSCH (0,1): cell specific (SysInfo) PO_UE_PUSCH (0,1): UE specific (RRC) α

(0,1) = 0.0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 (partial PL compensation by open loop)

Random access grant: j=2 PO_NOMINAL_PUSCH (2): PO_PRE + ∆Preamble_Msg3

PO_UE_PUSCH(2) = 0

a (2) = 1.0 (i.e. full PL compensation)

f(i): TPC (closed loop adjustment) 11


*PH = Power Headroom

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Open Loop PC vs. Closed Loop PC Open Loop Power Control Target: provide a basic operating point for a suitable PSD for an average MCS (average SINR):

Basic _ Operating _ Po int = P O_PUSCH ( j ) + α ( j ) ⋅ PL Open Loop Power Control takes into account effects like intercell interference and shadowing Based on pathloss Closed Loop PC f(i) adjustments

Target: Fine tuning around the basic operating point Adapt dynamically to the channel conditions (take into account e.g. fast fading) Correct the estimations of power from the open loop PC ulpcEnable enable UL closed loop PC LNCEL; true, false; false

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PSD: Power Spectral Density

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Open Loop PC P PUSCH(i) = min { P MAX,10 log10 ( M PUSCH(i)) + P O_PUSCH( j) + α ( j ) ⋅ PL + ∆TF (i) + f (i)} [dBm]

PO_PUSCH(j) = PO_NOMINAL_PUSCH (j) + PO_UE_PUSCH (j) j=0 -> PUSCH transmission with semi-persistent grant (not in RL10) j=1 -> PUSCH transmission with dynamic scheduling j=2 -> PUSCH transmission for random access grant

PO_NOMINAL_PUSCH(j) -> cell specific component signalled from system information for j=0, 1 This term is a common power level for all mobiles in the cell (used to control SINR) p0NomPusch Nominal Power for UE PUSCH Tx Power Calculation LNCEL; -126..24dbm; 1; -100 dBm PO_UE_PUSCH(j)

-> UE specific component provided by higher layers (RRC) for j=0,1

This term is a UE specific offset used to correct the errors from the estimation of the pathloss p0UePusch

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Power Offset for UE PUSCH Tx Power Calculation LNCEL; -8..7; 1; 0 dB

p0NomPusch - This parameter defines the UE-specific nominal power for the PUSCH. Used for P0_PUSCH calculation in UE uplink power control equation (P1) for controlling the mean received SNR for user data during (re)transmission corresponding to a received PDCCH with DCI format 0 associated with a new packet transmission. This parameter is used to control mean received SNR for user data . P0 could be sent semistatically configured in the network based on the measurements or it is so that I set a parameter which is broadcasted??

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PUSCH formula -

PL: pathloss [dB] = referenceSignalPower – higher layer filtered RSRP

This path loss compensation factor a is adjustable by

Alpha

O&M. α is a cell - specific parameter (broadcasted on BCH). α∈

ulpcAlpha

α

= 0 , no compensation

α

= 1 , full compensation

LNCEL; 0, 0.4..1.0; 0.1; 1.0 α 14


[0.0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0]

{ 0 ,1 } , fractional compensation

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Conventional & Fractional PC • Conventional PC schemes: – Attempt to maintain a constant SINR at the receiver – UE increases the Tx power to fully compensate for increases in the path loss • Fractional PC schemes : – Allow the received SINR to decrease as the path loss increases. – UE Tx power increases at a reduced rate as the path loss increases. Increases in path loss are only partially compensated.

– [+]: Improve air interface efficiency & increase average cell throughputs by reducing Intercell interference

• 3GPP specifies fractional power control for the PUSCH with the option to disable it & revert to conventional based on

α

UL SINR

Conventional Power Control: α=1

UE Tx Power

If Path Loss increases by 10 dB the UE Tx power increases by 10 dB 15


UL SINR

UE Tx Power

Fractional Power Control: α ≠ { 0 ,1}

If Path Loss increases by 10 dB the UE Tx power increases by < 10 dB

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MCS dependent component P PUSCH(i) = min { P MAX,10 log10 ( M PUSCH(i)) + P O_PUSCH( j) + α ( j ) ⋅ PL + ∆TF (i) + f (i)} [dBm] MPR∗ K s

∆ TF (i ) = 10 log10 (2

− 1)

for

K S = 1.25 deltaTfEnabled

0

Otherwise

Enabled TB size (MCS) impact to UE PUSCH power calculation LNCEL; Yes/No; No

MPR = TBS/N RE with NRE : number of RE, TBS = Transport Block Size

Ks - Enabling/disabling of the transport format dependent offset on a per UE basis If this parameter is enabled, PUSCH power calculation in UE uplink power control equation takes the Transport Block size in account during the power calculation TF = Transport Format Could be seen as dynamic offset of the TX power: when the BTS changes the MCS for the UE then the UE indirectly may adapt the power Increase the power if the Transport Format (MCS, TBS size, Number of Resource Blocks) it is so selected to increase the number of bits per Resource Element

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Ks - Enabling/disabling of the transport format dependent offset on a per UE basis. If this parameter is enabled, PUSCH power calculation in UE uplink power control equation (P1) takes the Transport Block size in account during the power calculation.

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UL-PC: PUCCH P PUCCH (i) = min{ P MAX , P 0_PUCCH ( j ) + PL + h(nCQI , n HARQ ) + ∆ F_PUCCH ( F ) + g (i )} [dBm] PPUCCH: PUCCH Power in subframe i Pmax: max. allowed power P0_PUCCH(j) = P0_NOMINAL_PUCCH (j) + P0_UE_PUCCH (j)

p0NomPucch Nominal Power for UE PUCCH Tx Power Calculation LNCEL; -126..24; 1; -100 dB

p0UePucch Power Offset for UE PUCCH Tx Power Calculation LNCEL; -8..7; 1; 0 dB

P0_NOMINAL_PUCCH : cell specific (SysInfo) P0_UE_PUCCH : UE specific (RRC) PL: pathloss [dB] = referenceSignalPower – higher layer filtered RSRP F_PUCCH

(F) : deltaFListPUCCH

Compensation Factor for different PUCCH formats

(see next slide)

For example if format 1a (1ACK) is having offset 0 then format 1b (2ACK) could have offset 3dB

PUCCH format 1, 1a, 1b: h(n) = 0 PUCCH format 2, 2a, 2b and : h(n) = 0 if nCQI < 4 h(n) = 10log10 (nCQI/4) otherwise

(here: normal CP, for extented CP also n HARQ to be considered, n:number of information bits )

g(i): TPC (closed loop adjustment)

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* For PUCCH higher degree of orthogonality could be assumed due to the usage of the orthogonal codes so alpha=1 (full compensation)

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deltaFListPUCCH Parameters

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Name

Object

Abbreviation

Range

Description

Default

DeltaF PUCCH List

LNCEL

dFListPucch

n/a

dFListPucch: SEQUENCE (see values below)

n/a

DeltaF PUCCH Format 1

LNCEL

dFpucchF1

-2, 0, 2 dB

Used to define the PUCCH format 1

0 dB

DeltaF PUCCH Format 1b

LNCEL

dFpucchF1b

1, 3, 5 dB

Used to define the PUCCH format 1b

1 dB

DeltaF PUCCH Format 2

LNCE

dFpucchF2

-2, 0, 1, 2 dB

Used to define the PUCCH format 2

0 dB

DeltaF PUCCH Format 2a

LNCE

dFpucchF2a

-2, 0, 2 dB

Used to define the PUCCH format 2a

0 dB

DeltaF PUCCH Format 2b

LNCEL

dFpucchF2b

-2, 0, 2 dB

Used to define the PUCCH format 2b

0 dB


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UL-PC: Control Scheme Open loop: level based Interference: considered by P 0 values  not need for explicit signalling RRC-BCCH: P0_NOMINAL_PUSCH, P0_NOMINAL_PUCCH, ALPHA, deltaFListPUCCH, deltaPreambleMsg3 PDCCH: DELTA_PUSCH, DE LTA_PUCCH MPUSCH taken from scheduling grant RRC-DCCH: P0_UE_PUSCH, P 0_UE_PUCCH, DELTA_TF_ENABLED, ACCUMULATION_ENABLED, P_SRS_OFFSET, filterCoefficient

Data

UE: PL MSRS (due to SRS configuration) SIB1, UE class: P MAX

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UL-PC: Closed loop - PUSCH and SRS (example) Closed loop adjustments: f(i) = f(i-1) +

PUSCH (i - KPUSCH)

ulpcEnable i.e. recursive determination

enable UL closed loop PC LNCEL; true, false; false

or

f(i) = where

PUSCH

(i - KPUSCH)

ulpcAccuEnable

i.e. absolute setting

PUSCH/PUCCH TPC commands accumulation enabled LNCEL; False/True; True In RL10 False not supported

PUSCH is the signalled TPC in subframe i-K PUSCH

For FDD: KPUSCH = 4 whether the recursive or absolute method is used



parameter Accumulation-enabled

Note, for RL09: - Accumulation-enabled always “true” tpcStepSize

- set “(-1,0,1,3) dB” supported; “(-1,1) dB” not supported

LNCEL;TPC step size set 1,0,1,3 (0), TPC step size set -1,1 (1); 0 In RL10 (1) is not supported

P (closed loop)

t 23


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UL-PC: Closed Loop - Process SIB/RRC parameters: P0_NOMINAL_PUSCH, P0_UE_PUSCH, P0_NOMINAL_PUCCH, P0_UE_PUCCH, ALPHA, deltaFListPUCCH, DELTA_TF_ENABLED, ACCUMULATION_ENABLED, deltaPreambleMsg3, P_SRS_OFFSET, filterCoefficient

Per UE measurements of • receive power of wanted signal • interference and noise

Calculation of average receive level per TTI. Calculation of SINR (two methods for I+N values) Transformation from Watt into dBm/dB domain.

Transformation into TF independent format

ENABLE_CLPC ENABLE_CLPC_PUSCH, ENABLE_CLPC_SRS; ENABLE_CLPC_PUCCH

time scale: TTI

Including or excluding of RSSI and SINR measurements from PUSCH in the Closed Loop PC component LNCEL; true; true

SINR_MAX, SINR_MIN, RSSI_MAX, RSSI_MIN

Clipping using adjustable parameters

WF_PUSCH_UE, WF_PUSCH_CELL, WF_SRS_UE, WF_SRS_CELL, WF_PUCCH_UE, WF_PUCCH_CELL

Weighting

TAVG_PUSCH_SRS_CONT, TAVG_PUSCH_SRS_DISCONT, TAVG_PUCCH_CONT, TAVG_PUCCH_DISCONT

Long term filtering/averaging of level and SINR using adjustable filter coefficients

Periodic reading of averaged level and averaged SINR value (time constant adjustable) Comparison with twodimensional decision matrix. Calculation of DELTA_ PUSCH and DELTA_ PUCCH values for the UE

DELTA_TF_ENABLED, deltaFListPUCCH

ulpcPuschEn

FILTER_OUTPUT_PERIOD

time scale: filter output period (adjustable by O&M)

UP_LEV_PUSCH_SRS, LOW_LEV_PUSCH_SRS, UP_QUAL_PUSCH_SRS, LOW_QUAL_PUSCH_SRS, UP_LEV_PUCCH, LOW_LEV_PUCCH, UP_QUAL_PUCCH, LOW_QUAL_PUCCH, minCumDeltaPUSCH, maxCumDeltaPUSCH, minCumDeltaPUCCH, maxCumDeltaPUCCH

ulpcPucchEn Commanding DELTA_PUSCH and DELTA_PUCCH values to the UE via PDCCH

DELTA_PUSCH, DELTA_PUCCH

t 24


Including or excluding of RSSI and SINR measurements from PUCCH in the Closed Loop PC component LNCEL; true; true

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UL-PC: Closed Loop - Process M e as u r e m e n t s a n d A v e r ag i n g Averaged* received level per TTI per UE:

Averaged* received SINR per TTI per UE:

• RSSIPUSCH/UE

Relevant for PUSCH and PUCCH: (I+N)UE and (I+N)cell

• RSSIPUCCH/UE

and for SRS: (I+N)cell

• RSSISRS/UE

(I+N)cell : all potential PRBs

relevant: PRBs allocated to the particular UE

(I+N)UE : allocated PRBs to the particular UE • SINRPUSCH/UE

* l i n e ar , b u t c o n v e r t e d t o d B m , d B f o r f u r t h e r deployment

• SINRPUSCH/cell • SINRPUCCH/UE • SINRPUCCH/cell • SINRSRS/cell

T r an s f o r m a t i o n i n i n d e p e n d e n t f o r m a t Normalization applies to:

UE and/or TF specific offsets get subtracted:

• PUSCH

∆TF

• PUCCH

∆PF_PUCCH

• SRS

h(n) PO_UE_PUSCH P0_UE_PUCCH

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UL-PC: Closed Loop - Process Clippi ng Averaged received level per TTI per UE:

Averaged received SINR per TTI per UE:

RSSI*** := min(max(RSSImin,RSSI***)RSSImax)

SINR*** := min(max(SINRmin,SINR***)SINRmax)

* ** P US CH /U E,

P UC CH/ UE ,

*** PUSCH/UE, PUSCH/cell, PUCCH/UE, PUCCH/cell, SRS/cell

S RS /U E

W e i g h t in g o f M C S i n d e p e n d e n t m e as u r e m e n t s PUSCH and SRS - composite SINR and RSSI : C _ SINR PUSCH / SRS =

SINR PUSCH / UE ⋅ WF _ PUSCH _ UE + SINR PUSCH / cell ⋅ WF _ PUSCH _ CELL + SINR SRS / cell ⋅ WF _ SRS _ CELL WF _ PUSCH _ UE + WF _ PUSCH _ CELL + WF _ SRS _ CELL

C _ RSSI PUSCH / SRS =

RSSI PUSCH / UE ⋅ WF _ PUSCH _ UE + RSSI SRS / UE ⋅ WF _ SRS _ UE WF _ PUSCH _ UE + WF _ SRS _ UE

PUCCH - composite SINR and RSSI : C _ SINR

PUCCH

=

SINR

PUCCH / UE

_ PUCCH ⋅ WF

C _ RSSI PUCCH = RSSI PUCCH / UE

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_ UE + SINR

PUCCH / cell

⋅ WF _ PUCCH

_ CELL

WF _ PUCCH _ UE + WF _ PUCCH _ CELL

Weighting factors WF_*** : range [1, 100]

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UL-PC: Closed Loop - Process Filtering RSSIPUSCH/SRS,filtered

SINRPUSCH/SRS,filtered

RSSIPUCCH,filtered

SINRPUCCH,filtered

ulpcReadPeriod Decision matrix for the

Decision matrix for the

PUSCH/SRS component

PUCCH component of

of the CLPC algorithm

the CLPC algorithm

DELTA_PUSCH

DELTA_PUCCH

value

value

Low pass filter first order (exponential moving average) :

y ( n)

=

c ⋅ y (n − 1) + (1 − c ) ⋅ x (n )

x: input (composite RSSI, SINR)

c: filter coefficient

y: output (filtered RSSI, SINR)

c = exp(-T/T avg ) i.e. impact = (1/e) at t = -T avg

n: step, max frequency = 1/TTI

Example: T = 1ms, T avg = 25 ms



c = 0.96

Time interval for sending averaged RSSI and SINR values to the decision matrix to determine power corrections in Closed Loop uplink power control. LNCEL; 10…2000ms; 10ms; 50 ms

filterCoeff Filter coefficient for RSRP measurements used to calculate pathloss.Value fc0 corresponds to k = 0, fc1 corresponds to k = 1, and so on. LNCEL; fc0 (0), fc1 (1), fc2 (2), fc3 (3), fc4 (4), fc5 (5), fc6 (6), fc7 (7), fc8 (8), fc9 (9), fc11 (10), fc13 (11), fc15 (12), fc17 (13), fc19 (14); fc4(4)

Initialization: y(0) := target RSSI/SINR

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UL-PC: Closed Loop - Process Decision matrix

ulpcUpqualSch High Thresh. For SINR for PUSCH LNCEL; -47...80dB; 1dB ; 11dB

SINR + 1 dB or + 3 dB

ulpcUpqualCch High Thresh. For SINR for PUCCH LNCEL; -47...80dB; 1dB ; 11dB

- 1 dB 1

- 1 dB 2

3

UP_QUAL_**

+ 1 dB or + 3 dB

Low Thresh. For SINR for PUSCH LNCEL; -47...80dB; 1dB ; 8dB

-1 dB

4

LOW_QUAL_**

ulpcLowqualSch

0 dB

+ 1 dB or + 3 dB

5

+ 1 dB or + 3 dB 7

ulpcLowqualCch Low Thresh. For SINR for PUCCH LNCEL; -47...80dB; 1dB ; 1dB

LOW_LEV_**

9

UP_LEV_**

Low Thresh. For RSSI for PUCCH LNCEL; -127...0dBm;1dBm ;-103dBm


+ 1 dB or + 3 dB 8

ulpcLowlevCch

28

6

RSSI

ulpcUplevCch High Thresh. For RSSI for PUCCH LNCEL; -127...0dBm;1dBm ;-98dBm

ulpcLowlevSch

ulpcUplevSch

Low Thresh. For RSSI for PUSCH LNCEL; -127...0dBm;1dBm ;-103dBm

High Thresh. For RSSI for PUSCH LNCEL; -127...0dBm;1dBm ;-98dBm

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Module Contents • Overview • UL-PC: Overview • UL-PC: PUSCH • UL-PC: PUCCH • UL-PC: Control Scheme • UL-PC: Closed Loop • UL-PC: Parameters and setting impacts • DL-PC: RL10 • DL-PC: PC on PDCCH

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Trade-off between coverage and capacity (based on simulations) P0 = -52 dBm α = 0.5 11186 kbps / 1910 kbps

P0 = -50 dBm α = 0.5 11833 kbps / 1796 kbps

P0 = -86 dBm α = 0.8 9044 kbps / 2098 kbps

P0 = -48 dBm α = 0.5 12318 kbps / 1579 kbps

P0 = -46 dBm α = 0.5 12625 kbps / 1247 kbps

P0 = -36 dBm α = 0.4 12924 kbps / 1329 kbps

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Exercise 1: UL PC Input: • UE1 gets assigned 4 PRB for PUSCH • d = 2 km • closed loop f(i) = 0 dB • S/I = 10 dB • N = -174 dBm • NFeNB= 2 dB • Rx ant gain = 18 dBi • Pmax = 23 dBm • parameter values for UL PC: default Note: PL[dB] for m acro case may be used, 1 slope model, clutter = rural (open), h BS = 30 m, h UE = 1.5 m, f = 2000 MHz: L(d) [dB ] = 105.27 + 35.22 log 10 ( d [ k m ] )

Tasks: - UL power for UE1 ? - expected SINR ?

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DL-PC RL10


RL10: (static) Cell Power Reduction • based on single parameter CELL_PWR_RED = 0.0, 0.1 … 10.0 dB •  cell size adjustment and coverage control

pMax

• flat Power Spectral Density (PSD) • semi-static MIMO_COMP (if enabled)

PSD

PSD

PSD = (Max_TX_Pwr – CELL_PWR_RED) – 10*log10( 12*# PRBs)

Allocated DL PRBs

Frequency

DL Pilots 33


Maximum output power LNCEL; 37.0 (0), 39.0 (1), 40.0 (2), 41.8 (3), 43.0 (4), 44.8 (5), 46.0 (6), 47.8 (7);37.0 dBm = 5 W 39.0 dBm = 8 W 40.0 dBm = 10 W 41.8 dBm = 15 W 43.0 dBm = 20 W 44.8 dBm = 30 W 46.0 dBm = 40 W 47.8 dBm = 60 W PSD = (Max_TX_Pwr – CELL_PWR_RED) – 10*log10( 12*# PRBs)

PDCCH

Time

PDSCH, PCH BCH, SCH

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DL-PC in RL10

dlpcMimoComp Gain used with TxDiv or 2x2 MIMO SM

Cell Power Reduction

LNCEL; 0..10; 0.1; 0 dB

PSD = (pMax - CELL_PWR_RED) - 10*log10( # PRBs_DL *12) - MIMO_COMP [dBm]

PSD: Power Spectral Density, which specifies the constant absolute Power per 15kHz Resource Element (RE) pMax: maximum eNodeB transmit power per Antenna in [dBm] CELL_PWR_RED: O&M parameter # PRBs_DL: maximum Number of downlink PRBs in given LTE Carrier Bandwidth MIMO_COMP: Compensation Factor MIMO_COMP = 0 dB for SISO/SIMO MIMO_COMP = 0...12 dB for MIMO Diversity and for MIMO Spatial Multiplexing - PSD given per antenna (RF amplifier outpu t) - P R B s n o t s c h e d u l e d a r e b l an k e d

applied to UE / cell specific channels and signals: - PSD_CELL_CTRL for BCCH i.e. PBCH+PDSCH, PCFICH and PCH - PSD_CELL_RS for reference signals (RS) / pilots - PSD_CELL_SYNC for synchronization channel - PSD_UE_PDSCH for UE specific part of PDSCH - PSD_UE_CTRL for PDCCH and PHICH

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Main target of DL-PC-CCH • DL Power Control for PDCCH is an additional mechanism interacting with DL AMC for PDCCH in order to make the signaling as robust as possible

• DL-PC-CCH aims at 1% target BLER but cannot modify AGG assignments • Main actions performed by DL-PC-CCH – Power reduction on CCEs with assigned AGG level higher than required – Power boosting on CCEs with assigned AGG level lower than required – Equal power relocation among all scheduled CCEs • Macro cell case #1 • Uniform UE distribution

(or equal)

 Very good CCEs (CQI highly above 1% BLER target)

Bad CCEs (AGG level too high to meet 1% BLER target) 

If still some power available, relocate equally among all CCEs 

4-CCE 8-CCE

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2-CCE

1-CCE

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Principles of DL-PC-AMC • PDCCH Power Control can be enabled/disabled by O&M switch • Maximum transmit power of the Power Amplifier cannot be exceeded ( pMax ; O&M) • Reduction and boosting range is strictly defined and is always considered as the limit for power level modification

• DL-PC-CCH operates together with DL-AMC-CCH on TTI basis • DCI messages with more than one CCE (AGG-…>1) have a flat PSD, thus all CCEs belonging to one scheduled UE are transmitted with the same power Short Name

Description

Range/ Step

Default Value

Parameter Scope

true, false

true

Cell

Changing parameter requires object locking. Operator configurable.

Remark

enablePcPdcch

Enabling/disabling PC for PDCCH. In case the parameter is disabled, a flat downlink PSD is used.

pdcchPcBoost

Maximum power boost per CCE.

0...10 dB, step 0.1 dB

4 dB

BTS

Not modifiable. Vendor configurable.

pdcchPcRed

Maximum power reduction per CCE.

0...10 dB, step 0.1 dB

6 dB

BTS


pdcchPcReloc

Maximum limit on the equal power relocation per CCE.

0...10 dB, step 0.1 dB

3 dB

BTS


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10 RA4121AEN10GLA1 Power Control

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