Post on 06-Apr-2018
transcript
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
1/20
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
2/20
Content
Overview
Huawei II Power Control Algorithm
Huawei III Power Control Algorithm
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
3/20
HUAWEI TECHNOLOGIES CO., LTD. Page 3Huawei Confidential
What is power control?
What is the aim of power control?
Power control: Adjust the transmit power of BTS and MS according
to the requirement.
Aim: Reduce the transmit power of BTS and MS on the basis of
ensured call quality, thus reducing the interference of the wholenetwork and reducing power consumption
Basis: Measurement reports from MS and BTS
Overview
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
4/20
HUAWEI TECHNOLOGIES CO., LTD. Page 4Huawei Confidential
Value measured
at downlink
Value measured at uplinkValue measured at uplink
ClassificationPower control includes uplink power control and downlink power
control and they are performed separately.
Uplink power control
adjust the transmit power of MS
Downlink power control
adjust the transmit power of BTS
Based on time slot
Multiplexer supersaturating
UL PC Allowed
DL PC Allowed
15 levels30dB
GSM900 20 levelsGSM900 or DCS1800 32 levels
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
5/20
HUAWEI TECHNOLOGIES CO., LTD. Page 5Huawei Confidential
Power Control Algorithm
PC Execution
Processing MR
PC Decision
The principles of power control
If receive level or signal quality is higher
than the expected value, the power is
reduced to some extent.
If receive level or signal quality is lower
than the expected value, the power is
increased to some extent.
Improve the accuracy and effectiveness of
the power control on the overall basis of
receive level and signal quality.
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
6/20
HUAWEI TECHNOLOGIES CO., LTD. Page 6Huawei Confidential
Huawei II Power Control Algorithm
HWIII Power Control Switch 0
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
7/20
HUAWEI TECHNOLOGIES CO., LTD. Page 7Huawei Confidential
Where Where power control is performed BTS or BSC)
Aim: reduce the load over Abis interface
improve the load over the BSC
shortening the response time
In 16K mode, if a TRX is configured with two or more SDCCHs, or if SD Dynamic
Allocation Allowed is set to Yes, it is recommended that you enable BTS MR pre-
processing. Recommendation that MR is reported once per second.
MR Preprocessing
Transfer original MR
Transfer BS/MS power class
Sent Freq of preprocessed MR
Notice
II
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
8/20
HUAWEI TECHNOLOGIES CO., LTD. Page 8Huawei Confidential
What Processing MR includes 3 step
Interpolation
Sequence number is incontinuous.
Lost of MRs Allowed MR Number Lost
RxlevRxqualBsPwrLevel linear interpolation
MsPwrLevel No interpolation
Compensation
RXLEV power class decrease/increase 2
Filter
Averaging filter
Filter length for UL RX_LEV
Filter Length for DL RX_LEV Filter Length for UL Qual
Filter Length for DL Qual
MR Compensation Allowed
II
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
9/20
HUAWEI TECHNOLOGIES CO., LTD. Page 9Huawei Confidential
How Step1: Power control request according to the RXLEV
Adjustment based on level = [RXLEV (upper threshold + lower threshold)/2]
Minus (-) means increase output power, positive (+) means decrease output power.
Requested adjustment increaseMAX Up Adj. PC Value by RX_LEV
Requested adjustment decrease Max Down Adj. Value Qual. Zone X
Step 2: Power control request according to the RXQUAL
RxQual>= UL/DL Qual Lower Threshold increase power Requested
adjustment MAX Up Adj.C Value by Qual RxQual
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
10/20
HUAWEI TECHNOLOGIES CO., LTD. Page 10Huawei Confidential
Example Assumption
The uplink RXLEV is -85 dBm
The RXQUAL class is 4.
The data configuration is as follows:
UL RX_LEV Upper Thrsh.: -60 dBm
UL RX_LEV Lower Thrsh.: -80 dBm
UL Qual. Upper Thrsh.: 0
UL Qual. Lower Thrsh.: 2 MAX Down Adj. Value Qual. Zone 0: 16 dB
MAX Down Adj. Value Qual. Zone 1: 8 dB
MAX Down Adj. Value Qual. Zone 2: 4 dB
MAX Up Adj. PC Value by RX_LEV: 16 dB
MAX Up Adj. PC Value by Qual.: 4 dB
What is the stable uplink
RXLEV after power control?
II
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
11/20
HUAWEI TECHNOLOGIES CO., LTD. Page 11Huawei Confidential
SA0 SA1SA0 SA0SA1SA1 SA2SA2SA2 SA3SA3SA3
BTS sends commands for
adjusting power and TA through
SACCH
MS gets power control
information
MS begins to send the
measurement report in the
previous multiframe
Among 26 multiframes,
the 12th frame sends
SACCH
BTS receives the
measurement report
The period for SACCH report is:
26 4104frames480ms
MS begins to use
new power and TA
MS begins to report new information of TA and
power control through the new SACCH
Implementation To MS three MR periods are needed from the command is
sent to the command is performed.
To BTS in the first MR periods the command is performed.
II
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
12/20
HUAWEI TECHNOLOGIES CO., LTD. Page 12Huawei Confidential
Huawei III Power Control Algorithm
HWIII Power Control Switch 1
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
13/20
HUAWEI TECHNOLOGIES CO., LTD. Page 13Huawei Confidential
What Processing MR
Interpolation
Sequence number is incontinuous.
Lost of MRs 5
Rxlev(k) Rxlev(k-1) ; Rxqual(k)Rxqual 7
BsPwrLevelMsPwrLevel No interpolation
Filter
Exponential filtering
ca_filtered1 (1) = ca (1); k=1
ca_filtered1 (k) = a*ca(k) + (1-a)*ca_filtered1 (k-1) k>1
qa_filtered1 (1) = qa(1); k=1
qa_filtered1 (k) = a*qa(k) + (1-a)*qa_filtered1 (k-1) k>1
arepresent the filter coefficients, a = 1 / (2^(K/2))K is filter length
ca(k)is acuual signal strength in the kth MR
qa(k) is acuual quality in the kth MR
ca_filtered1 (k)is the filtering value for signal strength.
qa_filtered1 (k)is the filtering value for quality
HWIII UL/DL RexLev Exponent Filter Length
HWIII UL/DL Rex Qual. Exponent Filter Length
III
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
14/20
HUAWEI TECHNOLOGIES CO., LTD. Page 14Huawei Confidential
HowStep1: Whether power control is necessary
If( (SThrUp >= ca_filtered(k) >= SThrDown)
&& (QThrUp >= qa_filtered(k) + QOffFh>= QThrDown) )
step(k) = step(k-1);
end;
else
go on;
SThrUp meansHWIII DL RexLev Upper Threshold
SThrDown meansHWIII DL RexLev Lower Threshold
QThrUp meansHWIII DL RexQual. Upper Threshold
QThrDown means
HWIII DL RexQual. Lower Threshold
QOffFh means hopping gain based on the lenth of MA, mapping as follow:
4691214161822CIR (dB)
76543210Rxqual
III
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
15/20
HUAWEI TECHNOLOGIES CO., LTD. Page 15Huawei Confidential
HowStep 2: Calculation step
BTS PC
step(k) = - ( sfactor*( BsTxMaxPower - g(k) - SThr) + qfactor*( qa_filtered(k) + QOffFh - QThr));
MS PC
step(k) = - ( sfactor*( MsTxMaxPower - g(k) - SThr) + qfactor*( qa_filtered(k) + QOffFh - QThr));
If step(k) >0step(k) =0;
SfactormeansHWIII RexLev Adjust FactorqfactorHWIII Rex Qual.Adjust Factor
g(k) means channel gain based on current transmit power and receive level
SThrmeans the average ofRxLev Upper ThresholdandLower Threshold
QThrmeans the average ofRxQual Upper ThresholdandLower Threshold
III
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
16/20
HUAWEI TECHNOLOGIES CO., LTD. Page 16Huawei Confidential
HowStep3: Protection and order
Protection of step:
if step(k) - step(k-1) < MaxDownSizestep(k) = step(k-1) + MaxDownSize;
else if step(k) - step(k-1) > MaxUpSize
step(k) = step(k-1) + MaxUpSize;
End
PC order
If step(k) step(k-1)
To BTSP = step(k)
To MS
P = MsTxMaxPower + step(k)
HWIII MAX Down Step
HWIII MAX Up Step
III
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
17/20
HUAWEI TECHNOLOGIES CO., LTD. Page 17Huawei Confidential
Example Assumption
Rxlev is -83dBm, Rxqual is 4. Power Level is 0
The data configuration is as follows
HWIII DL RexLev Upper/Lower Threshold : 33/25,
HWIII DL RexQual. Upper/Lower Threshold : 18/14.
HWIII DL RexLev Adjust Factor : 0.4
HWIII DL Rex Qual.Adjust Factor : 0.6
HWIII MAX Down Step : 6
HWIII MAX Up Step 8
No hopping
What is PC order?
III
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
18/20
HUAWEI TECHNOLOGIES CO., LTD. Page 18Huawei Confidential
AnswerStep1: whether PC is necessary
HWIII DL RexLev Upper/Lower Threshold : 33/25
Corresponding the range of Rxlev77dBm 85dBm
Current Rxlev is -83dBm in the range
HWIII DL RexQual. Upper/Lower Threshold : 18/14.
Corresponding the range of Rxqual13
Current value of Rxqual is 4 beyond the range,
PC is necessary.
Step2Calculate step
st-ep(k) = - (sfactor *( BsTxMaxPower - g(k) - SThr) + qfactor*( qa_filtered(k) + QOffFh - QThr));
g(k) = p(k) c(k);
c(k) = ca_filtered(k) + qa_filtered(k) - 10*log10 (1 + 10^( qa_filtered(k)/10));
Take it
p(k) 0 ca_filtered(k) 83 qa_filtered(k) 12
SThr81 QThr16 sfactor=0.4; qfactor=0.6;
Get step(k)=8.3
because step(k) >0 step(k) =0;
Because step(k) step(k1) =0; no PC order
III
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
19/20
HUAWEI TECHNOLOGIES CO., LTD. Page 19Huawei Confidential
Features Exponential Filtering
Exponential filtering accelerates the processing rate for the filtering based on the MRs
Interpolation Optimization
Used for the lost values in the MR. Interpolation optimization uses the signal levels in the
last MR for the lost signal levels and uses a constant value 7 for the lost signal quality
values.
Comprehensive DecisionUses an universal decision formula that comprehends the receive level and quality. Thus,
the rate of the power control decision is accelerated.
Different Thresholds
The quality threshold is specified based on the service type
FH Gain
Consider the influence of frequency hopping during Power Control Judgment
III
8/3/2019 01 G-LII 301 Power Control Algorithm of BSC6000-20081028-A-2.0
20/20
Thank you
www.huawei.com