TX RX Diversity

RAN

TX/RX Diversity

Issue

Draft

Date

2008-03-20

Part Number

Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd

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Website:

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Email:

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Copyright © Huawei Technologies Co., Ltd. 2008. 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.

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RAN TX/RX Diversity

Contents

Contents 1 Change History of TX/RX Diversity.......................................................................................1-1 2 Introduction to TX/RX Diversity.............................................................................................2-1 3 Technical Description of TX/RX Diversity............................................................................3-1 3.1 TX/RX Diversity Parameters..........................................................................................................................3-2 3.2 RX Diversity Algorithms................................................................................................................................3-3 3.3 TX Diversity Algorithms................................................................................................................................3-8

4 Implementing TX/RX Diversity..............................................................................................4-1 4.1 Enabling TX/RX Diversity..............................................................................................................................4-2 4.2 Reconfiguring TX/RX Diversity Parameters..................................................................................................4-3 4.3 Disabling TX/RX Diversity............................................................................................................................4-3

5 Maintenance Information About TX/RX Diversity.............................................................5-1 6 Reference Documents About TX/RX Diversity....................................................................6-1

Issue Draft (2008-03-20)


i

RAN TX/RX Diversity

Figures

Figures Figure 3-1 4-way RX diversity of one sector in the BTS3812E..........................................................................3-7 Figure 3-2 4-way RX diversity of one sector in the DBS3800............................................................................3-8 Figure 3-3 Structure of SCH transmitted in TSTD..............................................................................................3-8 Figure 3-4 STTD encoder for QPSK....................................................................................................................3-9 Figure 3-5 STTD encoder for 16QAM.................................................................................................................3-9 Figure 3-6 Transmitter and receiver in closed loop transmit diversity mode.....................................................3-10 Figure 3-7 Hardware connections for 2-way RX diversity and TX diversity for the BTS3812E......................3-16 Figure 3-8 Hardware connections for 2-way RX diversity and TX diversity for the DBS3800........................3-17



iii

RAN TX/RX Diversity

Tables

Tables Table 1-1 Document and product versions...........................................................................................................1-1 Table 2-1 NEs involved in TX/RX diversity........................................................................................................2-2 Table 2-2 RAN products and related versions......................................................................................................2-2 Table 3-1 TX/RX diversity parameters................................................................................................................3-2



v

RAN TX/RX Diversity

1 Change History of TX/RX Diversity

1

Change History of TX/RX Diversity

This describes the changes in different document versions.

Document and Product Versions Table 1-1 Document and product versions Document Version

RAN Version

RNC Version

NodeB Version

Draft (2008-03-20)

10.0

V200R010C01B050

V100R010C01B045

There are two types of changes, which are defined as follows: l

Feature change: refers to the change in the TX/RX diversity feature of a specific product version.

l

Editorial change: refers to the change in the information that was inappropriately described or the addition of the information that was not described in the earlier version.

Draft (2008-03-20) This is the draft release of RAN10.0.



1-1

RAN TX/RX Diversity

2 Introduction to TX/RX Diversity

2

Introduction to TX/RX Diversity

The signals on radio channels reach the receiver through multiple paths. If the signals are combined by the receiver, they are capable of anti-fading.

Introduction Definition Diversity is a transmission technique to enhance the system performance by receiving multipath signals and then combining them into one. In the WCDMA system, diversity can be performed in two directions: l

Receive diversity (RX diversity)

l

Transmit diversity (TX diversity)

Based on the number of antennas, receive diversity is of two types: l

2-way receive diversity

l

4-way receive diversity

Based on the feedback, TX diversity is of two types: l

Open loop transmit diversity (without feedback)

l

Closed loop transmit diversity (with feedback)

The open loop transmit diversity can be further categorized into: l

Space Time Transmit Diversity (STTD)

l

Time Switched Transmit Diversity (TSTD)

Purposes Diversity can improve the performance of RX channels and lower the requirement for the SIR of downlink signals and uplink signals.

Availability Network Elements Involved Table 2-1 lists the Network Elements (NEs) involved in TX/RX diversity. Issue Draft (2008-03-20)


2-1

RAN TX/RX Diversity


Table 2-1 NEs involved in TX/RX diversity UE

NodeB

RNC

MSC Server

MGW

SGSN

GGSN

HLR

√

√

√

–

–

–

–

–

NOTE

l

–: not involved

l

√: involved

RX diversity requires the NodeB to provide enough RF channels and demodulation resources that can match the number of diversity antennas. It has no special requirements for the RNC or UE. TX diversity requires the NodeB to provide RF channels two times those provided in no TX diversity mode. In addition, TX diversity requires the NodeB to support STTD, TSTD, and CP1. In TX diversity mode, the UE must support diversity reception, STTD, TSTD, and CP1. This diversity mode has no special requirements for the RNC. Software Releases Table 2-2 describes the versions of RAN products that support TX/RX diversity. Table 2-2 RAN products and related versions Product RNC

NodeB

Version BSC6800

V100R002 and later releases

BSC6810


DBS3800


BTS3812A


BTS3812E BTS3812AE


NOTE

l

RNC V100R002 and later releases support TSTD and STTD. RNC V100R008 and later releases support closed loop transmit diversity mode 1 (CP1).

l

RX diversity is performed only by the NodeB to improve the performance of RX channels. It does not involve the RNC or UE.

Impact Impact on System Performance TX diversity can improve the performance of UE in special circumstances, especially where there is unobvious multipath effect and the UE moves slowly. In such a scenario, capacity and 2-2



RAN TX/RX Diversity


coverage can be obviously increased, and CAPEX and OPEX can be reduced, under the condition that the QoS is guaranteed. TX diversity can improve the system performance significantly, although not all the users can experience it, limited by various scenarios and motion velocities. If different TX modes, however, are set for different cell circumstances, handovers between the cells with different TX modes become complex. As a result, the system performance may be degraded. Impact on Other Features None.

Capabilities None.



2-3

RAN TX/RX Diversity

3

3 Technical Description of TX/RX Diversity

Technical Description of TX/RX Diversity

About This Chapter This describes TX/RX diversity in terms of the configuration models, RX diversity algorithms, and TX diversity algorithms. 3.1 TX/RX Diversity Parameters This describes the TX/RX diversity parameters. 3.2 RX Diversity Algorithms RX diversity is a radio reception method in which a signal is obtained by combining or selecting signals from two or more independent sources. These signals have been modulated with identical information-bearing signals but may vary in their fading characteristics at any given instant. RX diversity can combat signal fading and interference. 3.3 TX Diversity Algorithms There are several TX diversity modes adopted in WCDMA 3GPP, which are TSTD, STTD, and closed loop transmit diversity. TSTD and STTD are open loop TX diversity modes, which do not need feedback information compared with the closed loop diversity mode.



3-1

RAN TX/RX Diversity


3.1 TX/RX Diversity Parameters This describes the TX/RX diversity parameters. Table 3-1 describes the TX/RX diversity parameters. Table 3-1 TX/RX diversity parameters

3-2

Parameter Name

Effective Level

Configuration on ...

Antenna Magnitude

Cell

NodeB

Antenna Channel No.1

Cell

NodeB

Subrack No. of Antenna Channel1

Cell

NodeB

Cabinet No. of Antenna Channel1

Cell

NodeB

Diversity Mode

Cell

NodeB

Work Mode

NodeB

NodeB

Cabinet No. of Power Amplifier1

Cell

NodeB

Subrack No. of Power Amplifier1

Cell

NodeB

Slot No. of Power Amplifier1

Cell

NodeB

TX diversity indication

Cell

RNC

STTD support indicator

Cell

RNC

CP1 support indicator

Cell

RNC

DPCH priority Tx diversity mode

Cell

RNC

Hspdsch priority Tx diversity mode

Cell

RNC

Closed loop time adjust mode indication

Cell

RNC

Closed loop time adjust mode

Cell

RNC



RAN TX/RX Diversity


3.2 RX Diversity Algorithms RX diversity is a radio reception method in which a signal is obtained by combining or selecting signals from two or more independent sources. These signals have been modulated with identical information-bearing signals but may vary in their fading characteristics at any given instant. RX diversity can combat signal fading and interference.

Rake Receiver The Rake receiver is adopted in WCDMA to receive signals. The Rake receiver is a radio receiver designed to counter the effects of multipath fading. It uses several baseband correlators to individually process multipath signal components. The outputs from the different correlators are combined to achieve improved reliability and performance. This helps increase SNR (or Eb/No) to a high level in a multipath environment than in a single path environment. RX diversity is a way to enhance the reception performance of uplink channels. It does not involve the RNC or UE. When RX diversity is applied, more than one antenna is used to receive signals. The Rake receiver selects powerful signals from multiple signals received by the antennas and then combines them.

Diversity Reception on the NodeB Huawei NodeBs support both RX diversity and no RX diversity. In RX diversity mode, the NodeB can be configured with 2 antennas (2-way), or 4 antennas (4-way) through the Antenna Magnitude parameter. If Antenna Magnitude is set to 1, no RX diversity is configured. Compared with 4-way RX diversity, the 4-way antennas in economical mode still adopt two RX channels to meet the wide coverage requirement (a maximum coverage radius of 180 km). If there are no obstacles such as buildings and hills and the signals do not incur any interference sources such as the frequency bands close to the transmit band or other electromagnetic radiation, the maximum coverage radius of 180 km can be supported. In 3GPP TS25.433 R6 and the previous release, the range of Tp (Propagation delay) value is from 0 to 255, and the step is 3 chip. Therefore, the maximum cell access range is 256 x 3 chip x 78.125 (m/chip) = 60000 m= 60 km, where 78.125 m/chip is derived from 300000 km/(100 ms x 38400 chip) = 78.125 (m/chip). As mentioned above, according to the range of Tp defined in 3GPP, 60 km is the maximum cell access radius. To support the cell radius in excess of 60 km or more, Huawei defines that: l

If the cell radius is within the range of [0, 60 km], the Tp step is 3 chip.

l

If the cell radius is within the range of [60 km, 120 km), the Tp step is 6 chip.

l

If the cell radius is longer than 120 km, the Tp step is 9 chip.

Therefore, the maximum cell radius shall reach 180 km (that is, 256 x 9 x 78.125) when the Tp step is 9 chip. In RX diversity mode, the NodeB does not require additional devices and works with the same algorithms. Compared with 1-way antenna with no RX diversity, 2-way RX diversity requires twice the number of RX channels. Similarly, 4-way RX diversity requires twice the number of RX channels compared with 2-way RX diversity. The number of RX channels depends on the settings of the antenna connectors on the cabinet top. Issue Draft (2008-03-20)


3-3

RAN TX/RX Diversity

3 Technical Description of TX/RX Diversity l

If Antenna Magnitude is set to 1, then the NodeB is in no RX diversity mode. In this case, only the Antenna Channel No.1 parameter, the associated cabinet number, and the subrack number need to be set.

l

If Antenna Magnitude is set to 2, then the NodeB is in 2-way RX diversity mode. In this case, the Antenna Channel No.1 parameter, the Antenna Channel No.2 parameter, the cabinet number, and the subrack number associated with each antenna need to be set.

l

If Antenna Magnitude is set to 4, then the NodeB is in 4-way RX diversity mode. In this case, the Antenna Channel No.1, Antenna Channel No.2, Antenna Channel No.3, and Antenna Channel No.4 parameters, the cabinet number, and the subrack number associated with each antenna need to be set.

The number of RX antennas is associated with Work Mode, the demodulation mode of NodeB. There are the following demodulation modes: 2-Channel Demodulation Mode (DEM_2_CHAN), Enhanced 2-channel Demodulation Mode (DEM_ENHANCED_2_CHAN), 4-Channel Demodulation Mode (DEM_4_CHAN), and Economical 4-Channel Demodulation Mode (DEM_ECON_4_ CHAN). l

If the NodeB works in 1-way, that is, no RX diversity mode, or in 2-way RX diversity mode, the demodulation mode is set to DEM_2_CHAN or DEM_ENHANCED_2_CHAN. Generally, Enhanced 2-channel Demodulation Mode is used to meet the requirements for small system capacity and high coverage performance, while 2-Channel Demodulation Mode is used to meet the requirements for large capacity.

l

If a sector of the NodeB works in 4-way RX diversity mode, the demodulation mode must be set to DEM_4_CHAN or DEM_ECON_4_CHAN. Economical 4-Channel Demodulation Mode refers to the fact that signals on the random access channel are received from two antennas and demodulated on four channels, which guarantees the maximum coverage radius of 180 km. In 4-Channel Demodulation Mode, NodeBs can cover only 30 km.

Parameter Name

Antenna Magnitude

Parameter ID

ANTM

GUI Range

1, 2, 4

Physical Range and Unit

1, 2, 4 Unit: none

3-4

Default Value

None

Optional/Mandatory

Mandatory

MML Command

ADD SEC (BTS3812E, BTS3812AE, BBU3806, BBU3806C)

Description

This parameter defines the number of RX antennas in a sector.

Parameter Name

Antenna Channel No.1

Parameter ID

ANT1N



RAN TX/RX Diversity


GUI Range

For the BTS3812E/BTS3812AE: N0A (Cabinet No.0A Ant.), N0B (Cabinet No.0B Ant.), N1A (Cabinet No.1A Ant.), N1B (Cabinet No.1B Ant.), N2A (Cabinet No.2A Ant.), N2B (Cabinet No.2B Ant.), N3A (Cabinet No.3A Ant.), N3B (Cabinet No.3B Ant.), N4A (Cabinet No.4A Ant.), N4B (Cabinet No.4B Ant.), N5A (Cabinet No.5A Ant.), N5B (Cabinet No.5B Ant.), R0A (RRU No. 0A Ant.), R0B (RRU No. 0B Ant.) For the DBS3800: R0A (RRU No. 0A Ant.), R0B (RRU No. 0B Ant.), R1A (RRU No. 1A Ant.), R1B (RRU No. 1B Ant.)


Same as the GUI Range Unit: none

Default Value

None

Optional/Mandatory

Mandatory

MML Command

l


l

MOD SEC (BTS3812E, BTS3812AE, BBU3806, BBU3806C)

Description

This parameter defines the numbered antenna connectors on the cabinet top that are associated with RX antenna 1 of a sector.

Parameter Name

Subrack No. of Antenna Channel1

Parameter ID

ANT1SRN

GUI Range

For the BTS3812E, refer to BTS3812E subrack information. For the DBS3800, refer to DBS3800 subrack information.



Default Value

BTS3812E: 3 DBS3800: none

Optional/Mandatory

Mandatory

MML Command

l


l




3-5

RAN TX/RX Diversity


Description

This parameter defines the numbered subracks that are associated with RX antenna 1 of a sector. The MAFU is in No.3 subrack.

Parameter Name

Cabinet No. of Antenna Channel1

Parameter ID

ANT1CN

GUI Range

MASTER (master cabinet)


MASTER Unit: none

Default Value

MASTER

Optional/Mandatory

Mandatory

MML Command

l


l


Description

This parameter defines the numbered cabinet that is associated with RX antenna 1 of a sector.

Parameter Name

Work Mode

Parameter ID

WM

GUI Range

DEM_2_CHAN, DEM_4_CHAN, DEM_ECON_4_ CHAN, DEM_ENHANCED_2_CHAN


2-Channels Demodulation Mode, 4-Channels Demodulation Mode, Economical 4-Channels Demodulation Mode, Enhanced 2-channels Demodulation Mode Unit: none

3-6

Default Value

DEM_2_CHAN

Optional/Mandatory

Mandatory

MML Command

MOD DEMMODE (BTS3812E, BTS3812AE, BBU3806, BBU3806C)

Description

This parameter defines the demodulation mode of a NodeB.



RAN TX/RX Diversity

3 Technical Description of TX/RX Diversity l

The parameters Antenna Channel No.2, Antenna Channel No.3, and Antenna Channel No.4 are similar to Antenna Channel No.1. They define the numbered antenna connectors associated with RX antenna 2, 3, and 4 of a sector.

l

The parameters Subrack No. of Antenna Channel2, Subrack No. of Antenna Channel3, and Subrack No. of Antenna Channel4 are similar to Subrack No. of Antenna Channel1. They define the numbered subracks associated with RX antennas 2, 3, and 4 of a sector.

l

The parameters Cabinet No. of Antenna Channel2, Cabinet No. of Antenna Channel3, and Cabinet No. of Antenna Channel4 are similar to Cabinet No. of Antenna Channel1. They define the numbered cabinets associated with RX antennas 2, 3, and 4 of a sector.

The configuration of the BTS3812AE is the same as that of the BTS3812E. The hardware connections of 4-way RX diversity per sector for different NodeBs are shown in Figure 3-1 and Figure 3-2. Figure 3-1 4-way RX diversity of one sector in the BTS3812E



3-7


RAN TX/RX Diversity

Figure 3-2 4-way RX diversity of one sector in the DBS3800

3.3 TX Diversity Algorithms There are several TX diversity modes adopted in WCDMA 3GPP, which are TSTD, STTD, and closed loop transmit diversity. TSTD and STTD are open loop TX diversity modes, which do not need feedback information compared with the closed loop diversity mode.

Time Switched Transmit Diversity TSTD is applied on SCH only. In TSTD, the transmit is switched between different antennas with a known periodicity, as shown in Figure 3-3. Figure 3-3 Structure of SCH transmitted in TSTD

In Figure 3-3, Cp represents Primary Synchronization Code (PSC) and csi,k represents Secondary Synchronization Codes (SSC), where i (= 0, 1, …, 63) indicates the number of the scrambling code group, and k (= 0, 1, …, 14) indicates the slot number. In even slots, both PSC and SSC are transmitted through antenna 1. In odd slots, both PSC and SSC are transmitted through antenna 2. 3-8



RAN TX/RX Diversity


TSTD is the simplest TX diversity mode in WCDMA. The UE can receive TSTD signals with the same method as used in no diversity mode. In this sense, the UE does not need to be aware whether TSTD is applied or not.

Space Time Transmit Diversity STTD uses the space-time block code at the NodeB to combat deep channel fading. Channel coding, rate matching, and interleaving are performed as in no diversity mode. Two STTD encoders are shown in Figure 3-4 and Figure 3-5. For QPSK, the STTD encoder operates on four symbols, b0, b1, b2, and b3, as shown in Figure 3-4. Figure 3-4 STTD encoder for QPSK

For 16QAM, STTD operates on blocks of eight consecutive symbols, b0, b1, b2, b3, b4, b5, b6, and b7, as shown in Figure 3-5. Figure 3-5 STTD encoder for 16QAM

The STTD support indicator parameter is used on the RNC LMT to indicate whether a cell supports STTD. Parameter Name

STTD support indicator

Parameter ID

STTDSupInd

GUI Range

STTD Supported, STTD not Supported


STTD Supported, STTD not Supported Unit: none



3-9

RAN TX/RX Diversity


Optional/Mandatory

Optional

MML Command

l

ADD CELLSETUP

l

MOD CELLSETUP

Description

This parameter indicates whether the cell supports STTD.

Configuration Rule and Restriction If a cell is configured to support the STTD mode, ensure that the associated local cell on the NodeB side supports TX diversity.

Closed Loop Transmit Diversity In closed loop transmit diversity, the UE periodically reports the estimated value of optimal transmit quantity (called feedback in the WCDMA network) on the uplink DPCCH, and the NodeB optimizes transmit signals according to the feedback. Figure 3-6 shows the concept of closed loop transmit diversity. Figure 3-6 Transmitter and receiver in closed loop transmit diversity mode

The UE periodically calculates the weights according to the information obtained from pilot signals. The weights are quantized and then sent to the NodeB on the reverse control channel. The NodeB adjusts the transmit power according to the feedback weights so that the UE can receive signals with the highest power. If the feedback mechanism in closed loop transmit diversity perfectly tracks the channel conditions of the downlink, the maximum Signal-to-Noise Ratio (SNR) of closed loop transmit diversity can be greater than that of STTD. Generally, closed loop transmit diversity provides the biggest gain in low velocities, while open loop transmit diversity is robust in high velocities and provides smaller gain in low velocities. 3-10



RAN TX/RX Diversity


The CP1 support indicator parameter is used on the RNC LMT to indicate whether a cell supports closed loop transmit diversity mode 1 (CP1). Parameter Name

CP1 support indicator

Parameter ID

CP1SupInd

GUI Range

CP1 Supported, CP1 not Supported


CP1 Supported, CP1 not Supported Unit: none

Default Value

None

Optional/Mandatory

Optional

MML Command

l

ADD CELLSETUP

l

MOD CELLSETUP

Description

This parameter defines whether the cell supports CP1.

Configuration Rule and Restriction If a cell is configured to support the CP1 mode, ensure that the associated local cell on the NodeB side supports TX diversity.

If a cell works in TX diversity mode, configure the following two parameters on the RNC LMT to specify the preferential TX diversity modes of DPCH and HS-PDSCH, because these two physical channels support both STTD and CP1. l

DPCH priority Tx diversity mode indicates the preferential TX diversity mode for DPCH, on which the service is carried.

l

Hspdsch priority Tx diversity mode indicates the preferential TX diversity mode for HSPDSCH, on which the HSDPA service is carried.

Parameter Name

DPCH priority Tx diversity mode

Parameter ID

DpchPrioTxDiversityMode

GUI Range

None, STTD, CP1


None, STTD, CP1 Unit: none

Default Value

None

Optional/Mandatory

Optional

MML Command

l

ADD CELLSETUP

l

MOD CELLSETUP



3-11

RAN TX/RX Diversity


Description

This parameter defines the preferential TX diversity mode of DPCH.

Parameter Name

Hspdsch priority Tx diversity mode

Parameter ID

HspdschPrioTxDiversityMode

GUI Range

None, STTD, CP1


None, STTD, CP1 Unit: none

Default Value

None

Optional/Mandatory

Optional

MML Command

l

ADD CELLSETUP

l

MOD CELLSETUP

Description

This parameter defines the preferential TX diversity mode of HS-PDSCH.

For closed loop transmit diversity, 3GPP defines two modes of reporting closed loop feedback information: j+1 and j+2, as described below: l

In j+1 mode, the feedback information of timeslot j is reported after (j+1)mod15 timeslots.

l

In j+2 mode, the feedback information of timeslot j is reported after (j+2)mod15 timeslots.

The modes are set on the RNC LMT through the two parameters: Closed loop time adjust mode indication and Closed loop time adjust mode. If the Closed loop time adjust mode indication parameter is set to FALSE, the NodeB processes the feedback information in j+1 mode. Parameter Name

Closed loop time adjust mode indication

Parameter ID

CLTAModeInd

GUI Range

TRUE, FALSE


TRUE, FALSE Unit: none

3-12

Default Value

FALSE

Optional/Mandatory

Optional

MML Command

l

ADD CELLSETUP

l

MOD CELLSETUP



RAN TX/RX Diversity


Description

This parameter indicates whether to set closed loop time adjustment mode for the cell. If this parameter is set to FALSE, the NodeB processes the feedback information in j+1 mode by default.

Parameter Name

Closed loop time adjust mode

Parameter ID

ClosedLoopTimeAdjustMode

GUI Range

OFFSET1, OFFSET2


OFFSET1 = (j+1)mod15; OFFSET2 = (j+2)mod15 Unit: slot

Default Value

None

Optional/Mandatory

Optional

MML Command

l

ADD CELLSETUP

l

MOD CELLSETUP

Description

This parameter specifies the time for adjusting the phase and amplitude of DL DCH upon reception of a response from UL DCH.

Transmit Diversity of a Cell If a cell works in TX diversity mode, the CPICH, PCCPCH, and SCH of the cell must work in TX diversity mode. If a cell works in TX diversity mode, the TX diversity indication parameter is set on the RNC LMT and the Diversity Mode parameter is set on the NodeB LMT. Parameter Name

TX diversity indication

Parameter ID

TxDiversityInd

GUI Range

TRUE, FALSE


TRUE, FALSE Unit: none

Default Value

None

Optional/Mandatory

Mandatory

MML Command

l

ADD CELLSETUP

l

MOD CELLSETUP



3-13

RAN TX/RX Diversity


Description

This parameter indicates whether to activate TX diversity of the downlink common physical channels of the cell.

Configuration Rule and Restriction If the downlink common physical channels of a cell are configured to support TX diversity, ensure that the associated local cell on the NodeB side also supports TX diversity.

Parameter Name

Diversity Mode

Parameter ID

DIVM

GUI Range

NO_TX_DIVERSITY, TX_DIVERSITY, HALFFREQ


No TX diversity, TX diversity, 0.5/0.5 Mode Unit: none

Default Value

NO_TX_DIVERSITY

Optional/Mandatory

Optional

MML Command


Description

This parameter defines the diversity mode of the sector.

When setting up a sector of the NodeB, you can set only the Diversity Mode parameter. The RF channels to be used are defined by the following parameters when local cells are set up on the NodeB, that is, the BTS3812E, BTS3812AE or DBS3800. Parameter Name

Cabinet No. of Power Amplifier1

Parameter ID

CN1

GUI Range

MASTER (master cabinet)


MASTER Unit: none

3-14

Default Value

MASTER

Optional/Mandatory

Mandatory

MML Command

ADD LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C)



RAN TX/RX Diversity


Description

This parameter specifies the numbered cabinet associated with the power amplifiers (PAs) in the main path when the sector works in no TX diversity mode or in TX diversity mode.

Parameter Name

Subrack No. of Power Amplifier1

Parameter ID

SRN1

GUI Range

For the BTS3812E, refer to BTS3812E subrack information. For the DBS3800, refer to DBS3800 subrack information.



Default Value

BTS3812E: 2 DBS3800: none

Optional/Mandatory

Mandatory

MML Command

ADD LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C)

Description

This parameter specifies the numbered subrack associated with the MTRU/RRU PAs in the main path when the sector works in no TX diversity mode or in TX diversity mode. The MTRU is in No.2 subrack.

Parameter Name

Slot No. of Power Amplifier1

Parameter ID

SN1

GUI Range

Refer to BTS3812E board information.



Default Value

None

Optional/Mandatory

Mandatory

MML Command

ADD LOCELL (BTS3812E, BTS3812AE)



3-15

RAN TX/RX Diversity


Description

This parameter specifies the numbered slot that are associated with the MTRU PAs in the main path when the sector works in no TX diversity mode or in TX diversity mode. The MTRU connects to the HBBI board in slot 0 or 1 of the baseband subrack. You do not need to specify the slot number if the RRU is used.

l

The Cabinet No. of Power Amplifier2 parameter is similar to Cabinet No. of Power Amplifier1. It define the numbered cabinet associated with power amplifier 2.

l

The Subrack No. of Power Amplifier2 parameter is similar to Subrack No. of Power Amplifier1. It defines the numbered subrack associated with power amplifier 2 .

l

The Slot No. of Power Amplifier2 parameter is similar to Slot No. of Power Amplifier1. It defines the numbered slot associated with power amplifier 2.

For the BTS3812AE, the configuration is the same as that of the BTS3812E. If a sector works in 2-way RX diversity mode and TX diversity is applied, you must set up the following hardware connections: l

l

If two pairs of MTRU and MAFU are used to implement TX diversity, you must crossconnect them as follows: –

Connect RXA1 on MAFU0 to RXB on MTRU1.

–

Connect RXA1 on MAFU1 to RXB on MTRU0.

–

Connect RXBs on both MAFUs in suspended state.

If two RRUs are used to implement TX diversity, jumpers for cross-connection are required.

The hardware connections for diversity configuration for different NodeBs are shown in Figure 3-7 and Figure 3-8. Figure 3-7 Hardware connections for 2-way RX diversity and TX diversity for the BTS3812E

3-16



RAN TX/RX Diversity


Figure 3-8 Hardware connections for 2-way RX diversity and TX diversity for the DBS3800



3-17

RAN TX/RX Diversity

4 Implementing TX/RX Diversity

4

Implementing TX/RX Diversity

About This Chapter This describes how to enable, disable, and reconfigure TX/RX diversity and provides some examples. 4.1 Enabling TX/RX Diversity This describes how to enable TX/RX diversity. 4.2 Reconfiguring TX/RX Diversity Parameters This describes how to reconfigure TX/RX diversity, for example, change the RX and TX diversity modes. 4.3 Disabling TX/RX Diversity This describes how to disable TX/RX diversity.



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4.1 Enabling TX/RX Diversity This describes how to enable TX/RX diversity.

Procedure Step 1 Install the hardware. The requirements for hardware for different configurations are as follows: l

RX diversity: The number of installed RX antennas must be the same as the number of antennas required by the RX diversity mode.

l

TX diversity: Two MTRUs and two MAFUs must be installed in the macro NodeB, and two RRUs must be installed in the DBS3800.

Step 2 Install the software. None. Step 3 Configure the data on the NodeB LMT. NOTE

You only need to perform Step 3.1 to enable RX diversity, either in 2-way or 4-way mode. You need to go through all the following steps to enable both RX diversity and TX diversity.

1.

Run the ADD SEC (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to add a sector on the NodeB, set the TX and RX diversity modes of the sector, and specify RX channel resources.

2.

Run the ADD LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to add a local cell on the NodeB, and specify TX channel resources.

Step 4 Configure the data on the RNC LMT. 1.

Run the ADD LOCELL command to add a local cell to the NodeB. NOTE

Local cell ID must be in accordance with Local Cell ID specified in Step 3.2.

2.

Run the ADD QUICKCELLSETUP command to quickly set up a cell. During the quick setup of the cell, most parameters are set to their default values, which speeds up the setup procedure.

3.

Run the MOD CELLSETUP command to set the TX diversity parameters of the cell.

4.

Run the ACT CELL command to activate the cell.

----End

Example The following example is based on TX diversity in the downlink and 2-way RX diversity in the uplink. //(1) Set up a local cell on the NodeB. ADD SEC: STN=0, SECN=1, SECT=LOCAL_SECTOR, ANTM=2, DIVM=TX_DIVERSITY, ANT1SRN=3, ANT1N=N0A, ANT2SRN=3, ANT2N=N1A; ADD LOCELL: LOCELL=0, STN=0, SECN=1, SECT=LOCAL_SECTOR, BBPOOLTYPE=GEN_POOL, SRN1=2, SN1=0, SRN2=2, SN2=1, ULFREQ=9850, DLFREQ=10800, HISPM=FALSE, MXPWR=430;

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//(2) Set up the cell on the RNC quickly, and modify its TX diversity parameters after the cell is set up. ADD LOCELL: NodeBName="3812E104", LoCell=0; ADD QUICKCELLSETUP:CellId=110, CellName="cell110", CnOpIndex=0, BandInd=Band1, UARFCNUplink=9850, UARFCNDownlink=10800, PScrambCode=110, TCell=CHIP256, LAC=9479, SAC=1, CfgRacInd=REQUIRE, RAC=1, URANUM=D1, URA1=1, NodeBName="3812E104", LoCell=0, SupBmc=FALSE; MOD CELLSETUP: CellId=110, TxDiversityInd=TRUE, LoCell=0, CLTAModeInd=TRUE, ClosedLoopTimeAdjustMode=OFFSET1, STTDSupInd=STTD_Supported, CP1SupInd=CP1_Supported, DpchPrioTxDiversityMode=STTD, HspdschPrioTxDiversityMode=STTD; ACT CELL: CellId=110;

Postrequisite Verify the Enabled Feature Use a UE that supports TX diversity to send a service setup request message. Then, check the diversity settings of related channels during the signaling procedure.

4.2 Reconfiguring TX/RX Diversity Parameters This describes how to reconfigure TX/RX diversity, for example, change the RX and TX diversity modes.

Context The RX and TX channels cannot be modified through MML commands. You need to delete the local cells and then add new ones.

Procedure Step 1 On the RNC LMT, run the DEA CELL command to deactivate the logical cell that is associated with the local cell on the NodeB that requires reconfiguration. Step 2 On the NodeB LMT, run the RMV LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to delete the local cell in the sector. Step 3 On the NodeB LMT, run the RMV SEC (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to delete the sector. Step 4 On the NodeB LMT, run the ADD SEC (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to set the TX and RX diversity modes and specify the RX antennas of the sector. Step 5 On the NodeB LMT, run the ADD LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to set the resources of TX channels of the local cell. Step 6 On the RNC LMT, run the MOD CELLSETUP command to modify the TX diversity parameters. Step 7 On the RNC LMT, run the ACT CELL command to activate the logical cell. ----End

4.3 Disabling TX/RX Diversity This describes how to disable TX/RX diversity. Issue Draft (2008-03-20)


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Procedure l

l

To change the RX diversity mode to the no RX diversity mode, perform the following steps: 1.

On the RNC LMT, run the DEA CELL command to deactivate the logical cell that is associated with the local cell on the NodeB.

2.

On the NodeB LMT, run the RMV LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to delete the local cell in the sector.

3.

On the NodeB LMT, run the RMV SEC (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to delete the sector.

4.

On the NodeB LMT, run the ADD SEC (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to set the Antenna Magnitude parameter to 1.

5.

On the NodeB LMT, run the ADD LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to add local cell to the sector.

6.

On the RNC LMT, run the ACT CELL command to activate the logical cell.

To change the TX diversity mode to the no TX diversity mode, perform the following steps: 1.

On the RNC LMT, run the MOD CELLSETUP command to set the TX diversity ind parameter to FALSE.

2.

On the NodeB LMT, run the RMV LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to delete the local cell in the sector.

3.

On the NodeB LMT, run the RMV SEC (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to delete the sector.

4.

On the NodeB LMT, run the ADD SEC (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to set Diversity Mode to NO_TX_DIVERSITY.

5.

On the NodeB LMT, run the ADD LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command to set the resources of TX channels of the local cell. NOTE

When the TX diversity mode is changed to the no TX diversity mode, you may not modify the parameters on the NodeB side; but the resources may be wasted.

----End

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5 Maintenance Information About TX/RX Diversity

Maintenance Information About TX/RX Diversity This describes maintenance information, including alarms and counters related to TX/RX diversity.

Alarms None.

Counters None.



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6 Reference Documents About TX/RX Diversity

6

Reference Documents About TX/RX Diversity

This describes references, including the 3GPP protocols and documents related to TX/RX diversity. l

3GPP TS 25.211, "Physical channels and mapping of transport channels onto physical channels (FDD)"

l

3GPP TS 25.214, "Physical layer procedures (FDD)"



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