eRAN3.0
Guide to Power Configuration in LTE TDD Networks
Issue
1.1
Date
2012-02-14
HUAWEI TECHNOLOGIES CO., LTD.
Copyright © Huawei Technologies Co., Ltd. 2012. All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.
Trademarks and Permissions and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd. All other trademarks and trade names mentioned in this document are the property of their respective holders.
Notice The purchased products, services and features are stipulated by the contract made between Huawei and the customer. All or part of the products, services and features described in this document may not be within the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements, information, and recommendations in this document are provided "AS IS" without warranties, guarantees or representations of any kind, either express or implied. The information in this document is subject to change without notice. Every effort has been made in the preparation of this document to ensure accuracy of the contents, but all statements, information, and recommendations in this document do not constitute a warranty of any kind, express or implied.
Huawei Technologies Co., Ltd. Address:
Huawei Industrial Base Bantian, Longgang Shenzhen 518129 People's Republic of China
Website:
http://www.huawei.com
Email:
[email protected]
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eRAN Guide to Power Configuration in LTE TDD Networks
About This Document
About This Document Author Prepared by
Lan Laixi
Date
yyyy-mm-dd
Reviewed by
Cheng Tangbo, Lei Ke, Zhou Zhibing, Tang Chengke, Hou Fangmin, Bi Zhiling, Ma Jindou
Date
yyyy-mm-dd
Reviewed by
Date
yyyy-mm-dd
Approved by
Date
yyyy-mm-dd
Change History Data
Version
Description
Prepared by
2012-01-30
V1.0
Completed the draft.
Lan Laixi
2012-02-14
V1.1
Included the following new changes based on the first review comments:
Lan Laixi
Issue 1.1 (2012-02-14)
Antenna port mapping mode
Section 4.2.1
Section 4.4
Appendix A
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eRAN Guide to Power Configuration in LTE TDD Networks
Contents
Contents About This Document....................................................................................................................ii 1 Overview.........................................................................................................................................1 2 Background Information..............................................................................................................2 2.1 LTE Pilot Diagram.............................................................................................................................................2 2.2 Power-related Parameters..................................................................................................................................3 2.3 Antenna Port Mapping Mode.............................................................................................................................4 2.4 RS Power Boosting............................................................................................................................................5
3 Impact of Pilot Power on Network Performance....................................................................7 3.1 Impact on Network Coverage............................................................................................................................7 3.2 Impact on Network Capacity.............................................................................................................................7
4 Power Configuration....................................................................................................................8 4.1 Basic Concepts...................................................................................................................................................8 4.2 Configuration Method......................................................................................................................................10 4.2.1 Calculation of the RS Power Based on the Specified RRU Power........................................................10 4.2.2 Calculation of the RRU Power Based on the Specified RS Power........................................................11 4.3 Configuration Principle....................................................................................................................................11 4.4 Configuration Suggestion................................................................................................................................12 4.4.1 Two-Antenna RRU.................................................................................................................................12 4.4.2 Four-Antenna RRU.................................................................................................................................12 4.4.3 Eight-Antenna RRU...............................................................................................................................12
5 U-Net Power Configuration......................................................................................................13 5.1 RSRP Definition..............................................................................................................................................13 5.2 Power Modeling Method.................................................................................................................................13 5.3 Configuration Process......................................................................................................................................14 5.4 Power Configuration Table..............................................................................................................................15
6 Conclusion:...................................................................................................................................17 Appendix A......................................................................................................................................18 Reference Document.......................................................................................................................19
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eRAN Guide to Power Configuration in LTE TDD Networks
6 Overview
1
Overview
The LTE time division duplex (TDD) technology is increasingly mature, and is being largely used by China Mobile first office application (FOA) sites and sites outside China. To ensure the successful deployment, power configuration during network planning is a crucial procedure. This document describes basic concepts, configuration methods, and planning guidelines for power configuration in TDD networks. The description involves protocols and algorithms for products and the tool platform. This document is intended for frontline personnel responsible for network optimization and planning.
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eRAN Guide to Power Configuration in LTE TDD Networks
6 Background Information
2
Background Information
2.1 LTE Pilot Diagram A cyclic prefix (CP) for the orthogonal frequency division multiplexing (OFDM) system is used to suppress multi-path fading on radio channels. The multimedia broadcast multicast service (MBMS) supported in LTE networks uses an extended CP. In this document, the frame format for the extended CP at the physical layer is not considered. Figure 1.1 shows the RS diagram for a normal CP. Figure 1.1 RS diagram for a normal CP One antenna port
R0
R0
R0
R0
R0
R0
R0
R0
l0
l6 l0
l6
Resource element (k,l)
Two antenna ports
R0
R0
R0
R0
R1
R0
l 6
R0
l0
R0
R1
Antenna port 0
l0
R1 l6 l 0
even-numbered slots
R3
R2
R3
R3
R2 l6
odd-numbered slots
Antenna port 1
R2
R2
R1
R1 l6
odd-numbered slots
l6
R1
R1
R0 l 6 l0
even-numbered slots
Reference symbols on this antenna port
R1
R0
Not used for transmission on this antenna port
R1 l6 l0
R1
R0
R0
R1
R1
R1
l6 l0
R0
R1
R1
R0
l0
Four antenna ports
R1
R0
R0
l0
R0
l0
R3 l6 l0
even-numbered slots
l 6
odd-numbered slots
Antenna port 2
l0
l 6 l0
even-numbered slots
l6
odd-numbered slots
Antenna port 3
For single-antenna ports, each symbol has two RS resource elements (REs) with an interval of five subcarriers.
For two-antenna ports, each symbol over each port has two RS REs with an interval of five subcarriers. If one of the REs for the symbol of a port functions as the RS RE, the other port does not transmit signals to prevent interference between signals over the two ports.
For four-antenna ports, the RS position for the first two antennas is the same as that for the two-antenna ports. In the time domain, the RS position for ports 2 and 3 is one
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eRAN Guide to Power Configuration in LTE TDD Networks
6 Background Information
OFDM symbol later than that for ports 1 and 2. In addition, if an RE has an RS over one antenna port, data is not transmitted over the corresponding REs over the other antenna ports.
2.2 Power-related Parameters Energy per resource element (EPRE) represents the power for each RE. A TypeA symbol represents an OFDM symbol without RS. A TypeB symbol represents an OFDM symbol with RS.
A : represents the ratio of the PDSCH RE power on an OFDM symbol without RS to the power for the RS RE. It is a linear value.
B : represents the ratio of the power for the physical downlink shared channel (PDSCH) RE on an OFDM symbol with RS to the power for the RS RE. It is a linear value. Formulas to calculate A are as follows: For four-antenna transmit diversity with the precoding technology:
A power -offset PA 10 log10 (2)
In other cases: A power -offset PA Where
power -offset 0 if downlink MU-MIMO is not enabled. Currently, most of the eRAN products use adaptive selection between TM2, TM3, or TM7. Therefore,
A PA or A PA 3 .
where
PA represents the user-equipment (UE)-level parameter configured during higher-level signaling. If PA changes, an eNodeB changes the power allocated to a UE. This parameter equals the power after downlink power control. If PA increases, the RE has a large power. Assume that the total power of an eNodeB remains unchanged, the power for the RE increases, which indicates that the signal to interference plus noise ratio (SINR) can be increased. However, if PA is too large, interference to neighboring cell increases, the power for the control channel decreases, and network coverage becomes unbalanced. All calculation results of the preceding formulas have a unit dB.
When configure the RS power, ensure that the power for Type A and TypeB symbols are the same. Otherwise, the eNodeB power is not efficiently used.
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6 Background Information
PB represents the index for the ratio of B / A . Table 1.1 lists the relationship between PB B / A
and
.
Table 1.1 Relationship between
PB and B / A
B / A
PB
Single-Antenna Port
Two- or Four-Antenna Port
0
1
5/4
1
4/5
1
2
3/5
3/4
3
2/5
1/2
PB is configured during the radio resource control (RRC) signaling, and is a universal value P for UEs. For all UEs, B has the same value. As listed in Table 1.1, the value of PB determines the ratio of PDSCH RE power for TypeA and TypeB symbols. If PB is set to an incorrect value, the PDSCH RE power for the two types of symbols are consistent with each other. As a result, power allocation is unbalanced.
2.3 Antenna Port Mapping Mode An antenna port is a logical port. Signals transmitted over each antenna port are generated based on the weight matrix of signals from physical antennas. Figure 1.2 shows an eightantenna with two ports. In this figure, 45° cross-polarization physical antennas are weighted and mapped to form two ports.
w1 w 2 w3 w4 0 0 0 0
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0 0 0 0 w1 w2 w3 w4
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6 Background Information
Figure 1.2 Eight-antenna cross-polarization mapping
2.4 RS Power Boosting RS power boosting is a technique used on the downlink for power control. With this technique, the coverage area in a cell expands. Different PB s correspond to different power for the RS RE, as shown in Figure 1.3. In this figure, Tx Ant represents the antenna ports.
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Use the two-antenna ports as an example. If PB equals 1 and PA equals –3 dB, the power for the RS RE of TypeB symbols increases by two units. However, the PDSCH RE power for TypeA and TypeB symbols remains one unit. Therefore, compared with the power for data channels, RS signals become strong. This procedure is called RS power boosting. After RS power boosting, the total power for each port is the same. This allows an eNodeB to allocate balanced resources in the time and frequency domain. Use the single-antenna ports as an example. If PB equals 3, the RS power increases by four units. However, the PDSCH RE power for TypeB symbols has only 2/5 units, and the PDSCH RE power for TypeA symbols remains one unit. Therefore, compared with the PDSCH RE power, the RS power increases, improving network coverage. If PB equals 0, for an antenna with two or four ports, the PDSCH RE power for TypeB symbols has 5/4 units, and the PDSCH RE power for TypeA symbols remains one unit. Therefore, the RS power does not boost compared with the PDSCH RE power for TypeB and TypeA symbols. In this case, the scenario where PB equals 0 is regarded as the non power boosting mode.
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eRAN Guide to Power Configuration in LTE TDD Networks
Figure 1.3 Relationship between
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6 Background Information
PB and CRS power boosting
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eRAN Guide to Power Configuration in LTE TDD Networks
3
6 Impact of Pilot Power on Network Performance
Impact of Pilot Power on Network Performance
Pilot power affects the network coverage and capacity. Therefore, the setting of the RS power ensures the balance between network coverage and capacity.
3.1 Impact on Network Coverage Large RS power results in a large RSRP for UEs, and the cell radius increases. However, if the pilot power is too large, the following problems occur:
Coverage overlap, which leads to handover failures and call drops.
Interference to neighboring cells (refer to interference margin increase), which leads to a cell radius decrease.
Network coverage unbalance between the data channel and common control channel.
Network coverage unbalance between uplink and downlink links.
If the RS power is too small, the cell radius decreases, coverage holes appear, and network coverage is unbalanced between different channels. As a result, network performance deteriorates.
3.2 Impact on Network Capacity If the RS power is too large and the eNodeB power remains unchanged, the PDSCH RE power decreases. As a result, network capacity decreases. In addition, large RS power causes interference to physical channels of neighboring cells if the REs with RSs overlap. As a result, the UE demodulation threshold increases, reducing the network capacity.
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6 Power Configuration
4
Power Configuration
4.1 Basic Concepts The remote radio unit (RRU) transmit power represents the maximum transmit power of a single antenna. Its value is smaller than the RRU rated power. The RRU output power represents the total output power of eNodeB equipment, and the power is measured on the cabinet top.
DL _ RS _ PowerBCH represents the power for the RS RE of a single physical antenna. It is delivered by the physical broadcast channel (PBCH) to all UEs in a cell, and depends on the network coverage area defined in the network plan. DL _ RS _ PowerBCH is the same as ReferenceSignalPwr defined on the local maintenance terminal (LMT). Table 3.1 lists the meanings of the ReferenceSignalPwr parameter. Table 3.1 Meanings of the ReferenceSignalPwr parameter MO
PDSCHCfg
Parameter ID
ReferenceSignalPwr
Parameter Name
Reference signal power
NE
eNodeB
MML Command
MOD PDSCHCFG LST PDSCHCFG
Meaning
Indicates the reference signal power of the cell. For details, see 3GPP TS 36.213.
IsKey
NO
Mandatory
NO
Dynamic Attribute
No
Feature ID
LBFD-002003/TDLBFD-002003 LBFD-002009/TDLBFD-002009
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LBFD-002016/TDLBFD-002016 Feature Name
Physical Channel Management Broadcast of system information Dynamic Downlink Power Allocation
Value Type
Interval Type
GUI Value Range
-600~500
Enumeration Number/Bit
N/A
Unit
0.1 dBm
Actual Value Range
-60~50
Default Value
182
Recommended Value
None
Impact
PDSCHCfg
Parameter Relationship
None
Access
Read & Write
Service Interrupted After Modification
No (And no impact on the UE in idle mode)
Interruption Scope
N/A
Interruption Duration (min)
N/A
Caution
None
Validation of Modification
The parameter modification has no impact on the equipment.
Impact on Radio Network Performance
1. Coverage: If the value of ReferenceSignalPwr is too large, cross-coverage occurs. This causes interference to other cells. If the value of ReferenceSignalPwr is too small, coverage holes appear. 2. Interference: The setting of ReferenceSignalPwr varies with the interference from neighboring cells. A large interference margin is required where the interference is strong. 3. Channel estimation: A larger value of ReferenceSignalPwr leads to higher channel estimation accuracy, a lower demodulation threshold, and higher receiver sensitivity, but it causes stronger interference to neighboring cells. 4. Capacity: A larger value of ReferenceSignalPwr brings
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6 Power Configuration
better coverage, but a large value limits the power used for the transmission of data and hence decreases the system capacity. Set ReferenceSignalPwr appropriately to ensure a reasonable tradeoff between coverage and capacity, effective channel estimation, and appropriate interference control. Introduced in Version...
V100R001C00
Attribute
Radio
Initial Value Setting Source
Default/Recommended value
4.2 Configuration Method 4.2.1 Calculation of the RS Power Based on the Specified RRU Power In most cases, operators specify output power for the cabinet top PRRU . Product power
P parameters include RS, PA and B . Assume that the output power for the cabinet top is 8x5 W, PRRU equals 46 dBm and the power over a single antenna is as follows:
PSingle PRRU 10lg 8 37 dBm Number of ports to be configured must be based on operator requirements and product feature algorithms. If two ports are configured and TypeA and TypeB symbols have the same PDSCH RE power,
PB
must be set to 1 according to Table 1.1.
If there are 100 resource blocks (RBs) with a bandwidth of 20 MHz, the RS power is as follows:
DL _ RS _ PowerBCH PsingleAntenna 10 log 12 N RB 10 log 1 PB 37 10 10 log 12 100 10 log 1 1 9.2dBm In this case, RS power is set to 92 dBm while
PB is set to 1.
PA is a parameter controlling the power allocated by the eNodeB to each UE. When downlink power control is disabled, RRC allocates the same PA to all UEs. When downlink power control is enabled, PA is changed based on the channel quality indicator reported by the UE. Issue 1.1 (2012-02-14)
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4.2.2 Calculation of the RRU Power Based on the Specified RS Power In actual applications, the power for products are configured by using ,
DL _ RS _ PowerBCH
PA , and PB .
Transmit power over a single antenna is calculated as follows:
PsingleAntenna DL _ RS _ PowerBCH 10 log 1 PB 10 log 12 N RB For RRUs with eight channels, output power for the RRU cabinet top is 40 W and power for each antenna is 5 W if the following conditions are met:
Two ports are configured
DL _ RS _ PowerBCH , PA , and PB are set to 92, -3, and 1, respectively.
The bandwidth is 20 MHz.
DL _ RS _ PowerBCH 92 represents that RS RE power over a single antenna is 9.2 dBm. PB 1 represents that RS power boosting is used. Transmit power over a single antenna is calculated as follows:
PsingleAntenna 9.2 10 log 1 1 10 log 12 100 37dBm Therefore, it equals 5 W (linear value). For an RRU with eight channels, the total power is 8x5 W. PDSCH RE power for TypeA and TypeB symbols can be calculated, as follows: PDSCH RE power for TypeA symbols (dBm) =
- 10×log10(
)
PDSCH RE power for TypeB symbols (dBm) = RE power for data in the TypeA symbol (dBm) + 10×log10(ρB/ρA) N_Subcarrier represents the number of full-band subcarriers.
P 3
3dB
P 1
If two ports are configured, A indicates A . In addition, B , and therefore TypeA and TypeB symbols have the same PDSCH RE power. For a single port, PDSCH RE power for TypeA and TypeB symbols is 15.2 dBm. The antenna port is formed by eight antennas, and therefore RE power over a single antenna is 6.2 dBm. NOTE During product power configuration, obtained output power for the RRU must not be greater than the rated total transmit power for the RRU.
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6 Power Configuration
4.3 Configuration Principle Power configuration involves the following principles:
Network coverage is balanced between uplink and downlink, and power for public channels and service channels are balanced.
Coverage is ensured, interference is reduced, and capacity and coverage are balanced.
TypeA and TypeB symbols have the same PDSCH RE power.
TypeA and TypeB symbols have the same total power which is efficiently used.
4.4 Configuration Suggestion Power must be planned based on product features and application scenarios. For details about power configurations in different scenarios, see appendix A. The following are power configuration suggestions for RRUs with different channels:
4.4.1 Two-Antenna RRU RRU3231 with the transmit power of 2x20 W has two channels when two ports are configured. When system bandwidth is 20 MHz, set to 1, -3, and 122, respectively.
PB , PA , and ReferenceSignalPwr are
4.4.2 Four-Antenna RRU The RRU3235 working on 2.5 GHz has the transmit power of 4x5 W when two ports are configured. When system bandwidth is 20 MHz, 1, -3, and 122, respectively.
PB , PA , and ReferenceSignalPwr are set to
4.4.3 Eight-Antenna RRU The RRU3233 with the transmit power of 8x5 W has eight channels and two antenna ports are configured by default. respectively.
PB
,
PA
, and ReferenceSignalPwr are set to 1, -3, and 92,
In actual planning, the default configuration is recommended. During network optimization, ReferenceSignalPwr must be slightly changed to rectify faults, such as poor coverage, over coverage, and strong interference. NOTE Generally, to ensure that the power for TypeA and TypeB symbols is used up at the same time, configurations for
PB
and antenna ports remain unchanged during network optimization.
The RRUs with eight or two channels are used in China Mobile while RRUs with eight channels are used in sites outside China, for example, at the Japan WCP site.
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eRAN Guide to Power Configuration in LTE TDD Networks
5
6 U-Net Power Configuration
U-Net Power Configuration
5.1 RSRP Definition RS power is used in U-Net to calculate RSRP, interference and receive power of channel signals. Table 3.2 lists the RSRP definition in 3GPP TS 36.211 [3]. Table 3.2 RSRP definition Definition
Reference signal received power (RSRP), is defined as the linear average over the power contributions (in [W]) of the resource elements that carry cell-specific reference signals within the considered measurement frequency bandwidth. For RSRP determination the cell-specific reference signals R0 according TS 36.211 [3] shall be used. If the UE can reliably detect that R1 is available it may use R1 in addition to R0 to determine RSRP. If receiver diversity is in use by the UE, the reported value shall be equivalent to the linear average of the power values of all diversity branches.
NOTE R0 represents antenna port 0.
5.2 Power Modeling Method In U-Net, RS power equals RS RE transmit power over R0. Power for other control physical channels can be modeled by setting an offset for the RS RE power, as follows:
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6 U-Net Power Configuration
Table 3.3 Modeling method for downlink control physical channels Parameter
Description
Default Value
Unit
OffsetSCH
Offset of the RE power for the synchronization channels against RS RE power
0
dB
Offset PBCH
Offset of the RE power for the broadcast channels against RS RE power
-3
dB
Offset PCFICH
Offset of the PCFICH RE power against RS RE power
-3
dB
Offset PDCCH
Offset of the RE power for the control channels against RS RE power
-3
dB
Offset PHICH
Offset of the physical HARQ indicator channel (PHICH) RE power against RS RE power
0
dB
When downlink power control is disabled, number of ports over an antenna, settings of PA and PB must be considered during PDSCH power modeling. That is, power over a single antenna must be calculated with RS power, the number of RBs, number of antenna ports, and PB . PDSCH RE power for TypeA and TypeB symbols must be calculated with PA and the number of antenna ports.
When downlink power control is enabled, U-Net changes the PA of the UE based on channel quality reported by the UE and the user attribute of the UE to increase power utilization efficiency. NOTE If downlink power control is enabled during U-Net simulation, the enabling of inter-cell interference coordination (ICIC) is recommended. If downlink ICIC is enabled, the enabling of downlink power control is recommended. In U-Net V300R007, downlink power control and ICIC are disabled at the same time by default.
5.3 Configuration Process The RRU with the transmit power of 8x5 W is used as an example to specify the configuration theory for the RS power in U-Net. At the bandwidth of 20 MHz, if two ports are configured, and PA and PB are set to -3 and 1, respectively, RS RE transmit power is 9.2 dBm, which can be obtained based on the following formula:
PsingleAntenna DL _ RS _ PowerBCH 10 log 1 PB 10 log 12 N RB , where Issue 1.1 (2012-02-14)
PsingleAntenna 10 log(5000) 37dBm
.
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6 U-Net Power Configuration
The Number of transmission antenna port parameter is set to 2. This indicates that four antennas are mapped over one antenna port. RS power over R0 port is as follows:
RS _ PowerU Net 9.2 10 log 4 15.2dBm The general formula is as follows:
RS _ PowerU Net PRRU 10 log 12 RBn 10 log N port 10 log 1 PB 12 RBn N port PRRU 10 log 1 PB 15.2dBm where PRRU represents actual RRU output power (46 dBm), RBn represents the number of full-band RBs (100 RB at the bandwidth of 20 MHz), and antenna ports (two ports) configured in the system.
N port
represents the number of
NOTE RS power configured in U-Net must be one of the RS RE power over R0. RS RE power is set to 15.2 dBm in U-Net by default.
5.4 Power Configuration Table Table 3.4 lists power configuration for single-antenna and two-antenna ports in U-Net. Table 3.4 Power configuration in U-Net Nu mbe r of RBs
Single-Antenna Port
PB 0
PB 1
PB 2
PB 3
PB 0
PB 1
PB 2
PB 3
20
100
9.2
12.2
14
15.2
6.2
9.2
11
12.2
40
15
75
10.5
13.5
15.2
16.5
7.4
10.5
12.2
13.5
10
40
10
50
12.2
15.2
17
18.2
9.2
12.2
14
15.2
10
40
5
25
15.2
18.2
20
21.2
12.2
15.2
17
18.2
10
40
3
15
17.4
20.5
22.2
23.5
14.4
17.4
19.2
20.5
10
40
1.4
6
21.4
24.4
26.2
27.4
18.4
21.4
23.2
24.4
20
43
20
100
12.2
15.2
17
18.2
9.2
12.2
14
15.2
20
43
15
75
13.5
16.5
18.2
19.5
10.4
13.5
15.2
16.5
20
43
10
50
15.2
18.2
20
21.2
12.2
15.2
17
18.2
20
43
5
25
18.2
21.2
23
24.2
15.2
18.2
20
21.2
20
43
3
15
20.4
23.5
25.2
26.5
17.4
20.4
22.2
23.5
Total RRU Power (W)
Total RRU Power (dBm)
band Width
10
40
10
(MHz)
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Two-Antenna Port
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Nu mbe r of RBs
Single-Antenna Port
PB 0
PB 1
PB 2
PB 3
PB 0
PB 1
PB 2
PB 3
1.4
6
24.4
27.4
29.2
30.4
21.4
24.4
26.2
27.4
46
20
100
15.2
18.2
20
21.2
12.2
15.2
17
18.2
40
46
15
75
16.5
19.5
21.2
22.5
13.4
16.5
18.2
19.5
40
46
10
50
18.2
21.2
23
24.2
15.2
18.2
20
21.2
40
46
5
25
21.2
24.2
26
27.2
18.2
21.2
23
24.2
40
46
3
15
23.4
26.5
28.2
29.5
20.4
23.4
25.2
26.5
40
46
1.4
6
27.4
30.4
32.2
33.4
24.4
27.4
29.2
30.4
80
49
20
100
18.2
21.2
23
24.2
15.2
18.2
20
21.2
80
49
15
75
19.5
22.5
24.2
25.5
16.4
19.5
21.2
22.5
80
49
10
50
21.2
24.2
26
27.2
18.2
21.2
23
24.2
80
49
5
25
24.2
27.2
29
30.2
21.2
24.2
26
27.2
80
49
3
15
26.4
29.5
31.2
32.5
23.4
26.4
28.2
29.5
80
49
1.4
6
30.4
33.4
35.2
36.4
27.4
30.4
32.2
33.4
Total RRU Power (W)
Total RRU Power (dBm)
band Width
20
43
40
(MHz)
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eRAN Guide to Power Configuration in LTE TDD Networks
6 Conclusion:
6
Conclusion:
At present, transmit power for the eNodeB is evenly allocated to each subcarrier. Therefore, transmit power for each subcarrier is affected by the system bandwidth. When the total power remains unchanged, a broader bandwidth results in lower average power for each subcarrier. To improve power configuration in LTE mode, PB , PA and ReferenceSignalPwr are configured. The power configuration for service channels can be calculated based on the RS power. It is recommended that PA and PB are set to 1 and -3 dB, respectively. With this configuration, network is in the optimal performance, and RS power is the same as the power for TypeA or TypeB service channels. Power for PDCCH, PHICH, PCFICH, PBCH, primary synchronization channels, and secondary synchronization channels is set by configuring the offset against the RS power. When U-Net power is used, RS power is the power over R0, which is set to 15.2 dBm by default.
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eRAN Guide to Power Configuration in LTE TDD Networks
Appendix A
Appendix A
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eRAN Guide to Power Configuration in LTE TDD Networks
Reference Document
Reference Document TS 36.211 V8.6.0-Physical channels and modulation
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