Download - TX RX Diversity

RAN

TX/RX Diversity

Issue Draft

Date 2008-03-20

Part Number

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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............................................................................3-13.1 TX/RX Diversity Parameters..........................................................................................................................3-23.2 RX Diversity Algorithms................................................................................................................................3-33.3 TX Diversity Algorithms................................................................................................................................3-8

4 Implementing TX/RX Diversity..............................................................................................4-14.1 Enabling TX/RX Diversity..............................................................................................................................4-24.2 Reconfiguring TX/RX Diversity Parameters..................................................................................................4-34.3 Disabling TX/RX Diversity............................................................................................................................4-3

5 Maintenance Information About TX/RX Diversity.............................................................5-1

6 Reference Documents About TX/RX Diversity....................................................................6-1

RANTX/RX Diversity Contents

Issue Draft (2008-03-20) Huawei Proprietary and ConfidentialCopyright © Huawei Technologies Co., Ltd

i

Figures

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

RANTX/RX Diversity Figures


iii

Tables

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

RANTX/RX Diversity Tables


v

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

DocumentVersion

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.

RANTX/RX Diversity 1 Change History of TX/RX Diversity


1-1

2 Introduction to TX/RX Diversity

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

Introduction

Definition

Diversity is a transmission technique to enhance the system performance by receiving multipathsignals 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 SIRof downlink signals and uplink signals.

Availability

Network Elements Involved

Table 2-1 lists the Network Elements (NEs) involved in TX/RX diversity.

RANTX/RX Diversity 2 Introduction to TX/RX Diversity


2-1

Table 2-1 NEs involved in TX/RX diversity

UE NodeB RNC MSCServer

MGW SGSN GGSN HLR

√ √ √ – – – – –

NOTE

l –: not involved

l √: involved

RX diversity requires the NodeB to provide enough RF channels and demodulation resourcesthat can match the number of diversity antennas. It has no special requirements for the RNC orUE.

TX diversity requires the NodeB to provide RF channels two times those provided in no TXdiversity 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. Thisdiversity 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 Version

RNC BSC6800 V100R002 and later releases

BSC6810 V200R009 and later releases

NodeB DBS3800 V100R006 and later releases

BTS3812A V100R005 and later releases

BTS3812E

BTS3812AE V100R008 and later releases

NOTE

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

l RX diversity is performed only by the NodeB to improve the performance of RX channels. It doesnot involve the RNC or UE.

ImpactImpact on System Performance

TX diversity can improve the performance of UE in special circumstances, especially wherethere is unobvious multipath effect and the UE moves slowly. In such a scenario, capacity and

2 Introduction to TX/RX DiversityRAN

TX/RX Diversity

2-2 Huawei Proprietary and ConfidentialCopyright © Huawei Technologies Co., Ltd

Issue Draft (2008-03-20)

coverage can be obviously increased, and CAPEX and OPEX can be reduced, under thecondition that the QoS is guaranteed.

TX diversity can improve the system performance significantly, although not all the users canexperience 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 TXmodes become complex. As a result, the system performance may be degraded.

Impact on Other Features

None.

CapabilitiesNone.

RANTX/RX Diversity 2 Introduction to TX/RX Diversity


2-3

3 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 ParametersThis describes the TX/RX diversity parameters.

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

3.3 TX Diversity AlgorithmsThere are several TX diversity modes adopted in WCDMA 3GPP, which are TSTD, STTD, andclosed loop transmit diversity. TSTD and STTD are open loop TX diversity modes, which donot need feedback information compared with the closed loop diversity mode.

RANTX/RX Diversity 3 Technical Description of TX/RX Diversity


3-1

3.1 TX/RX Diversity ParametersThis describes the TX/RX diversity parameters.

Table 3-1 describes the TX/RX diversity parameters.

Table 3-1 TX/RX diversity parameters

Parameter Name Effective Level Configuration on ...

Antenna Magnitude Cell NodeB

Antenna Channel No.1 Cell NodeB

Subrack No. of AntennaChannel1

Cell NodeB

Cabinet No. of AntennaChannel1

Cell NodeB

Diversity Mode Cell NodeB

Work Mode NodeB NodeB

Cabinet No. of PowerAmplifier1

Cell NodeB

Subrack No. of PowerAmplifier1

Cell NodeB

Slot No. of PowerAmplifier1

Cell NodeB

TX diversity indication Cell RNC

STTD support indicator Cell RNC

CP1 support indicator Cell RNC

DPCH priority Tx diversitymode

Cell RNC

Hspdsch priority Txdiversity mode

Cell RNC

Closed loop time adjustmode indication

Cell RNC

Closed loop time adjustmode

Cell RNC

3 Technical Description of TX/RX DiversityRAN

TX/RX Diversity



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

Rake Receiver

The Rake receiver is adopted in WCDMA to receive signals. The Rake receiver is a radio receiverdesigned to counter the effects of multipath fading. It uses several baseband correlators toindividually process multipath signal components. The outputs from the different correlators arecombined 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 notinvolve the RNC or UE. When RX diversity is applied, more than one antenna is used to receivesignals. The Rake receiver selects powerful signals from multiple signals received by theantennas and then combines them.

Diversity Reception on the NodeB

Huawei NodeBs support both RX diversity and no RX diversity. In RX diversity mode, theNodeB can be configured with 2 antennas (2-way), or 4 antennas (4-way) through the AntennaMagnitude 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 RXchannels 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 interferencesources 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 isfrom 0 to 255, and the step is 3 chip. Therefore, the maximum cell access range is 256 x 3 chipx 78.125 (m/chip) = 60000 m= 60 km, where 78.125 m/chip is derived from 300000 km/(100ms x 38400 chip) = 78.125 (m/chip). As mentioned above, according to the range of Tp definedin 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 Tpstep is 9 chip.

In RX diversity mode, the NodeB does not require additional devices and works with the samealgorithms. Compared with 1-way antenna with no RX diversity, 2-way RX diversity requirestwice the number of RX channels. Similarly, 4-way RX diversity requires twice the number ofRX channels compared with 2-way RX diversity. The number of RX channels depends on thesettings of the antenna connectors on the cabinet top.



3-3

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 subracknumber need to be set.

l If Antenna Magnitude is set to 2, then the NodeB is in 2-way RX diversity mode. In thiscase, the Antenna Channel No.1 parameter, the Antenna Channel No.2 parameter, thecabinet 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 thiscase, the Antenna Channel No.1, Antenna Channel No.2, Antenna Channel No.3, andAntenna Channel No.4 parameters, the cabinet number, and the subrack numberassociated 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 DemodulationMode (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 forsmall system capacity and high coverage performance, while 2-Channel DemodulationMode 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 mustbe set to DEM_4_CHAN or DEM_ECON_4_CHAN. Economical 4-ChannelDemodulation Mode refers to the fact that signals on the random access channel are receivedfrom two antennas and demodulated on four channels, which guarantees the maximumcoverage radius of 180 km. In 4-Channel Demodulation Mode, NodeBs can cover only 30km.

Parameter Name Antenna Magnitude

Parameter ID ANTM

GUI Range 1, 2, 4

Physical Range and Unit 1, 2, 4Unit: none

Default Value None

Optional/Mandatory Mandatory

MML Command ADD SEC (BTS3812E, BTS3812AE, BBU3806,BBU3806C)

Description This parameter defines the number of RX antennas in asector.

Parameter Name Antenna Channel No.1

Parameter ID ANT1N


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.)

Physical Range and Unit Same as the GUI RangeUnit: none

Default Value None


MML Command l ADD SEC (BTS3812E, BTS3812AE, BBU3806,BBU3806C)

l MOD SEC (BTS3812E, BTS3812AE, BBU3806,BBU3806C)

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

Parameter Name Subrack No. of Antenna Channel1

Parameter ID ANT1SRN

GUI Range For the BTS3812E, refer to BTS3812E subrackinformation.For the DBS3800, refer to DBS3800 subrackinformation.


Default Value BTS3812E: 3DBS3800: none






3-5

Description This parameter defines the numbered subracks that areassociated with RX antenna 1 of a sector. The MAFU isin No.3 subrack.

Parameter Name Cabinet No. of Antenna Channel1

Parameter ID ANT1CN

GUI Range MASTER (master cabinet)

Physical Range and Unit MASTERUnit: none

Default Value MASTER




Description This parameter defines the numbered cabinet that isassociated 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

Physical Range and Unit 2-Channels Demodulation Mode, 4-ChannelsDemodulation Mode, Economical 4-ChannelsDemodulation Mode, Enhanced 2-channelsDemodulation ModeUnit: none

Default Value DEM_2_CHAN


MML Command MOD DEMMODE (BTS3812E, BTS3812AE,BBU3806, BBU3806C)

Description This parameter defines the demodulation mode of aNodeB.


TX/RX Diversity



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

l The parameters Subrack No. of Antenna Channel2, Subrack No. of AntennaChannel3, and Subrack No. of Antenna Channel4 are similar to Subrack No. ofAntenna 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 AntennaChannel3, and Cabinet No. of Antenna Channel4 are similar to Cabinet No. of AntennaChannel1. They define the numbered cabinets associated with RX antennas 2, 3, and 4 ofa 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 inFigure 3-1 and Figure 3-2.

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

3.3 TX Diversity AlgorithmsThere are several TX diversity modes adopted in WCDMA 3GPP, which are TSTD, STTD, andclosed loop transmit diversity. TSTD and STTD are open loop TX diversity modes, which donot need feedback information compared with the closed loop diversity mode.

Time Switched Transmit DiversityTSTD is applied on SCH only. In TSTD, the transmit is switched between different antennaswith 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 scramblingcode group, and k (= 0, 1, …, 14) indicates the slot number. In even slots, both PSC and SSCare transmitted through antenna 1. In odd slots, both PSC and SSC are transmitted throughantenna 2.


TX/RX Diversity



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

Space Time Transmit DiversitySTTD uses the space-time block code at the NodeB to combat deep channel fading. Channelcoding, rate matching, and interleaving are performed as in no diversity mode. Two STTDencoders 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 Figure3-4.

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 cellsupports STTD.

Parameter Name STTD support indicator

Parameter ID STTDSupInd

GUI Range STTD Supported, STTD not Supported

Physical Range and Unit STTD Supported, STTD not SupportedUnit: none



3-9

Optional/Mandatory Optional

MML Command l ADD CELLSETUP

l MOD CELLSETUP

Description This parameter indicates whether the cell supportsSTTD.

Configuration Rule and Restriction

If a cell is configured to support the STTD mode, ensure that the associated local cell on theNodeB side supports TX diversity.

Closed Loop Transmit DiversityIn closed loop transmit diversity, the UE periodically reports the estimated value of optimaltransmit quantity (called feedback in the WCDMA network) on the uplink DPCCH, and theNodeB optimizes transmit signals according to the feedback. Figure 3-6 shows the concept ofclosed 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 pilotsignals. 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 canreceive signals with the highest power.

If the feedback mechanism in closed loop transmit diversity perfectly tracks the channelconditions of the downlink, the maximum Signal-to-Noise Ratio (SNR) of closed loop transmitdiversity can be greater than that of STTD.

Generally, closed loop transmit diversity provides the biggest gain in low velocities, while openloop transmit diversity is robust in high velocities and provides smaller gain in low velocities.


TX/RX Diversity



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

Parameter Name CP1 support indicator

Parameter ID CP1SupInd

GUI Range CP1 Supported, CP1 not Supported

Physical Range and Unit CP1 Supported, CP1 not SupportedUnit: none

Default Value None



l MOD CELLSETUP

Description This parameter defines whether the cell supports CP1.


If a cell is configured to support the CP1 mode, ensure that the associated local cell on theNodeB side supports TX diversity.

If a cell works in TX diversity mode, configure the following two parameters on the RNC LMTto specify the preferential TX diversity modes of DPCH and HS-PDSCH, because these twophysical 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 HS-PDSCH, on which the HSDPA service is carried.

Parameter Name DPCH priority Tx diversity mode

Parameter ID DpchPrioTxDiversityMode

GUI Range None, STTD, CP1

Physical Range and Unit None, STTD, CP1Unit: none

Default Value None



l MOD CELLSETUP



3-11

Description This parameter defines the preferential TX diversitymode of DPCH.

Parameter Name Hspdsch priority Tx diversity mode

Parameter ID HspdschPrioTxDiversityMode

GUI Range None, STTD, CP1

Physical Range and Unit None, STTD, CP1Unit: none

Default Value None



l MOD CELLSETUP

Description This parameter defines the preferential TX diversitymode of HS-PDSCH.

For closed loop transmit diversity, 3GPP defines two modes of reporting closed loop feedbackinformation: 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 modeindication and Closed loop time adjust mode. If the Closed loop time adjust modeindication parameter is set to FALSE, the NodeB processes the feedback information in j+1mode.

Parameter Name Closed loop time adjust mode indication

Parameter ID CLTAModeInd

GUI Range TRUE, FALSE

Physical Range and Unit TRUE, FALSEUnit: none

Default Value FALSE



l MOD CELLSETUP


TX/RX Diversity



Description This parameter indicates whether to set closed loop timeadjustment mode for the cell. If this parameter is set toFALSE, the NodeB processes the feedback informationin j+1 mode by default.

Parameter Name Closed loop time adjust mode

Parameter ID ClosedLoopTimeAdjustMode

GUI Range OFFSET1, OFFSET2

Physical Range and Unit OFFSET1 = (j+1)mod15; OFFSET2 = (j+2)mod15Unit: slot

Default Value None



l MOD CELLSETUP

Description This parameter specifies the time for adjusting the phaseand amplitude of DL DCH upon reception of a responsefrom UL DCH.

Transmit Diversity of a CellIf a cell works in TX diversity mode, the CPICH, PCCPCH, and SCH of the cell must work inTX diversity mode.

If a cell works in TX diversity mode, the TX diversity indication parameter is set on the RNCLMT and the Diversity Mode parameter is set on the NodeB LMT.

Parameter Name TX diversity indication

Parameter ID TxDiversityInd

GUI Range TRUE, FALSE

Physical Range and Unit TRUE, FALSEUnit: none

Default Value None



l MOD CELLSETUP



3-13

Description This parameter indicates whether to activate TXdiversity of the downlink common physical channels ofthe cell.


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

Physical Range and Unit No TX diversity, TX diversity, 0.5/0.5 ModeUnit: none

Default Value NO_TX_DIVERSITY


MML Command ADD SEC (BTS3812E, BTS3812AE, BBU3806,BBU3806C)

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. TheRF channels to be used are defined by the following parameters when local cells are set up onthe NodeB, that is, the BTS3812E, BTS3812AE or DBS3800.

Parameter Name Cabinet No. of Power Amplifier1

Parameter ID CN1

GUI Range MASTER (master cabinet)

Physical Range and Unit MASTERUnit: none

Default Value MASTER


MML Command ADD LOCELL (BTS3812E, BTS3812AE, BBU3806,BBU3806C)


TX/RX Diversity



Description This parameter specifies the numbered cabinetassociated with the power amplifiers (PAs) in the mainpath when the sector works in no TX diversity mode orin TX diversity mode.

Parameter Name Subrack No. of Power Amplifier1

Parameter ID SRN1

GUI Range For the BTS3812E, refer to BTS3812E subrackinformation.For the DBS3800, refer to DBS3800 subrackinformation.


Default Value BTS3812E: 2DBS3800: none


MML Command ADD LOCELL (BTS3812E, BTS3812AE, BBU3806,BBU3806C)

Description This parameter specifies the numbered subrackassociated with the MTRU/RRU PAs in the main pathwhen the sector works in no TX diversity mode or in TXdiversity 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


MML Command ADD LOCELL (BTS3812E, BTS3812AE)



3-15

Description This parameter specifies the numbered slot that areassociated with the MTRU PAs in the main path whenthe sector works in no TX diversity mode or in TXdiversity mode. The MTRU connects to the HBBI boardin slot 0 or 1 of the baseband subrack.You do not need to specify the slot number if the RRUis used.

l The Cabinet No. of Power Amplifier2 parameter is similar to Cabinet No. of PowerAmplifier1. It define the numbered cabinet associated with power amplifier 2.

l The Subrack No. of Power Amplifier2 parameter is similar to Subrack No. of PowerAmplifier1. It defines the numbered subrack associated with power amplifier 2 .

l The Slot No. of Power Amplifier2 parameter is similar to Slot No. of PowerAmplifier1. 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 thefollowing hardware connections:l If two pairs of MTRU and MAFU are used to implement TX diversity, you must cross-

connect 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.

l 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 Figure3-7 and Figure 3-8.

Figure 3-7 Hardware connections for 2-way RX diversity and TX diversity for the BTS3812E


TX/RX Diversity



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



3-17

4 Implementing TX/RX Diversity

About This Chapter

This describes how to enable, disable, and reconfigure TX/RX diversity and provides someexamples.

4.1 Enabling TX/RX DiversityThis describes how to enable TX/RX diversity.

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

4.3 Disabling TX/RX DiversityThis describes how to disable TX/RX diversity.

RANTX/RX Diversity 4 Implementing TX/RX Diversity


4-1

4.1 Enabling TX/RX DiversityThis 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 togo through all the following steps to enable both RX diversity and TX diversity.

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

2. Run the ADD LOCELL (BTS3812E, BTS3812AE, BBU3806, BBU3806C) command toadd 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, whichspeeds 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

ExampleThe following example is based on TX diversity in the downlink and 2-way RX diversity in theuplink.

//(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;

4 Implementing TX/RX DiversityRAN

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//(2) Set up the cell on the RNC quickly, and modify its TX diversity parameters after the cellis 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;

PostrequisiteVerify the Enabled Feature

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

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

ContextThe RX and TX channels cannot be modified through MML commands. You need to delete thelocal cells and then add new ones.

ProcedureStep 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 diversityparameters.

Step 7 On the RNC LMT, run the ACT CELL command to activate the logical cell.

----End

4.3 Disabling TX/RX DiversityThis describes how to disable TX/RX diversity.

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Procedurel 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 thatis 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.l 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 diversityind 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 localcell.

NOTE

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

----End

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5 Maintenance Information About TX/RXDiversity

This describes maintenance information, including alarms and counters related to TX/RXdiversity.

AlarmsNone.

CountersNone.

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6 Reference Documents About TX/RXDiversity

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

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

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

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