Bravo | BMB0900 | BMB0900 Installation and Debugging

BMB Multi -Carrier Power Amplifier
Installation And Debugging
Bravo Tech (Shen Zhen) Co.,Ltd
A leading provider for smart coverage enhancement solution in
the worldwide wireless communication industry
Catalogue
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Explain of function
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The skills of installation and debugging
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Classical case of fault location
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Questions & Discussion
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Functions
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Amplify the downlink signal, could enhance the output power of BTS to 150W, extent
coverage range of BTS.
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Amplify uplink signal, reduce the noise figure of BTS, enhance the receiver sensitive.
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Provider automatic bypass protection.
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Input attenuator inside, so there is no need to adjust the output power of BTS. The
operation of BTS reset, frequency adjustment won’t make system fault or halt.
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Local & remote monitoring, user can select local and remote monitoring according to
their requirement .
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Support diversity reception and amplifier.
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System Block Diagram
Duplexer
Rx
BTS0
Tx/Rx
Duplexer
LNA
ANT0
Tx/Rx
Combiner
BTS
MCPA
BTS1
Tx/Rx
Filter
Rx
ANT1
Rx
LNA
Duplexer
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Main Function Module
Multi carrier amplifier adopt module design, so it is convenience
and efficient to installation and maintenance :
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BMB multi carrier power amplifier ( high linear power amplifier adopt the
technique of pre-distortion and feed-forward )
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LNA lower noise amplifier ( high sensitive, lower noise, gain linear
adjustment )
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Duplex combiner unite ( high separation and high power duplex,
automatic attenuator combiner )
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RF relay ( equipment fault, realize the power cut and automatic bypass )
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Supply power unite
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Central control unite ( local and remote monitoring and maintenance
control )
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MCPA Principle of signal processing
Pilot Tone
Insert
1st Loop
Amplitude
Adjust
1st Loop
Phase
Adjust
Main
Amp
Signal
Sampling
Output
Error Signal
Cancellation
Second
Loop
First Loop
Input
Carrier
Signal
Cancellation
1st Loop
Amplitude
Adjust
1st Loop
Phase
Adjust
2nd Loop
Amplitude
Adjust
1st Loop
Cancellation
Detection
2nd Loop
Phase
Adjust
2nd Loop
Amplitude
Adjust
Error
Amp
2nd Loop
Phase
Adjust
Pilot
Tone
Insert
Pilot Tone
Receive
Pilot Tone
Generator/
Receiver
Microcontroller
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•MCPA Principle of signal processing
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Technique advantage of MCPA and SCPA
If there are two carriers and output power is 150W. The inter-modulation (IMD) of
SCPA and MCPA as following:
SCPA IMD ≤ 30dBc
MCPA IMD ≥ 70dBc
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MCPA Testing Report
If there are two or four carriers in f2~f4 and output power is 150W then the
MCPA IMD≥70dBc
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MCPA vs SCPA
•Ability of Multi-carrier amplifier and processing: MCPA can amplifier all carriers
of one sector at the same time.
•Flexible configuration: when BTS add channel, it needn’t to add MCPA module,
so can save cost for BTS update.
•Small enclosure: save space of BTS installation, simple and quick installation.
Tx/Rx
SCPA
49dBm/carrier
combi ner
Duplexer
45.5dBm/carrier
loss3.5dB
Tx/Rx
SCPA
SCPA
49dBm/carrier
42dBm/carrier
loss3.5dB
BTS
MCPA
BTS1
Tx/Rx
Filter
combi ner
loss3.5dB
SCPA
ANT0
Tx/Rx
49dBm/carrier
Rx
Tx/Rx
LNA
Combiner
combi ner
Tx/Rx
Duplexer
Rx
BTS0
Tx/Rx
ANT1
Rx
LNA
Duplexer
49dBm/carrier
SCPA
MCPA
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Installation Process
Site Measuring
Solution design
OME statistic
CQT test statistic
BTS coverage range
Solution evaluation
System Optimize
Installation and debugging
OME statistic
DT test statistic
CQT test statistic
BTS coverage range
Effect evaluation
Compare the test data
Best effect
Test process end
Document management
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Installation --- Step 1
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Record BTS information: number of carriers, power of carrier, type of
combiner, length of feeder, situation of power supply and feeder distribution.
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Feasibility analysis: Gdown=Pout-Pin=Pout-(PBTS-Loss)
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Analyses the geography environment and wireless environment of optimize
area ( Choose reasonable site to get the best optimize effect )
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DT 、 CQT Test ( convenience for effect evaluation after equipment
operated )
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OMC Traffic statistic analysis ( Mainly for capacity of traffic analysis )
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Solution design and evaluation.
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Installation --- Step 2
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The installation location’s choosing and fixation
The MCPA can be mounted on the outside floor or wall. The
amplifier should be fixed near to the antenna as far as possible
and the followings are the installation requirements :
Firstly, the location for installation should be non corrosive and
non high tension electricity leakage.
Secondly, if the amplifier should be mounted on the wall, the wall
bearing should be no less than 55 kg, and the wall should be built
by concrete or bricks so that the plug bolts can be fixed. The
stone wall or mud wall can’t be considered.
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Installation --- Step 3
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Wiring manner and Power source choosing
1. The power cable should be connected firmly, the power connector can not
be loosed and broken, and be careful about the connector ground terminal.
2. The power cable must be connect with air-break switch (10A ).
3. All the wire covering of the cables shouldn’t be damaged and the ground
wire should be better contact.
4. All the cables should be placed properly, and the turning should be relaxed.
The through cable should be straight, smooth and without cross. The cables
in the same directions should be bound to branches and the branches also
should be tidy and unified.
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Installation --- Step 4: Project measuring and testing
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The gain setting of PA : Before testing the PA, first put
the switch of PA gain on the ‘ ON’ side, that means the
PA gain is ‘0’. Then adjust the gain step-by-step
according to the estimated value. While adjusting, leave
‘1’ margin in order to prevent overpower and device
damage.
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The gain setting of LNA : For engineering experience,
the gain setting of LNA = 8~12dB is recommended.
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The test of VSWR and Power : The VSWR and power
can be read from a handheld monitor or a computer.
The VSWR can be tested by the spectrum analyzer at
the BTS ANT terminal also.
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Installation --- Step 4 : Project measuring and testing
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The test of MODEL : Insert a SIM into the MODEL (pay attention to the
direction), read the working state of the device from a test cell phone and
make sure that the phone can control the device.
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The test of DT 、 CQT : After testing and setting, when the device is
employed, the test of DT and CQT should be conducted in this area. And the
test location should coincide with the test location before device installation
so as to compare and analyze the data.
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The OMC speech system and interference analysis : Measure the
speech quantities, connection success rates, cut-off rates, switching over
rates and the balance situation of interference link before and after the
device installation, then analyze those data in order to estimate the effects of
the device.
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Effects evaluation : Make a comprehensive contrastive analysis and
record the test report, according to the data above.
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Maintenance --- Error positioning
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Remote positioning
:
1. Checking the OMC of the base station and alarm information may help to
estimate.
2. Checking the speech quantity, connection success and failure rate,
switchover success rate, link balancing and interference parameter of
the Mobile base station would help us to identify the error of base station
or error of the Power amplifier.
3. Comparing the speech parameter between normal period and error
period can help us to know which part of the base station was damaged.
Therefore, we can prepare a new device advance and improve the
maintenance efficiency.
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•Maintenance --- Error positioning
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On-the-spot Estimation :
1. Before maintenance, first check the indicating lamp and judge the error according to
the state of indicating lamp.
2. Find the error location through reading the state parameters value in a handheld
terminal.
3. Decide the error through dialing DT and CQT.
4. Set the device in the state of by-pass, then give a judgment by comparing the by-pass
state with the working state.
5. Take apart the device, draw off the Power Amplifier unit, then take a detailed
examination.
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Conclusion : According to the methods above, the error of amplifier, LNA, or
Power source and so on can be found correctly.
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Maintenance --- Ordinary errors
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No downlink output power : Power amplifier without electricity,
amplifier’s own error, duplexer’s error, mixer’s error and relay’s error may
cause this trouble. If there is something wrong with the PA, the load or ring
isolator usually was damaged and standing wave alarm often
accompanied. Then the trouble unit can be found through testing PA’S
temperature. Besides, the errors of duplexer and mixer can cause that the
PA has no input signal or the input signal become weak. And the error of
RF relay can be examined by the working state of by-pass.
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Error of Low Noise Amplifier : This trouble can be examined through
dialing cell phone or the current value of the handheld terminal.
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Error of the Power Source: Firstly check the indicator lamp in the panel
and fan, then use the multi-meter to examine which current is wrong.
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Maintenance --- Ordinary errors
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Error of Duplexer : It is a passive device, and the error chance is
less. Once this device broken down, the Mobile base station would warn
an alarm.
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Error of Mixer : As our mixer contained an ATT attenuator, so the
error may cause the failure of adjusting gain or PA without input signal.
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Error of controlling panel (including lamp panel) : This error
may cause the failure of gain adjusting, failure of state information reading,
or no power and by-pass error.
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Error of controlling unit : If the remote monitoring failed, there must
something wrong with Model and controlling panel, or the SIM card isn’t
fixed well, Model has no power and the port may be blocked.
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Maintenance --- Typical Case
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Warning alarm of the base station lead to the failure of device working :
After the BMB900 was installed in the base station, once the TMB was powered
on, the BTS has VSWR alarm and the channel was shut down. Firstly, we
thought there must be something wrong with the soft jumping wire. But after
exchanging the BST0BST1 port, the main channel still has VSWR alarm. We
by-pass the device and found that the bypass working is normally. Then after
rechecking, we found that the duplexer is faulty (cold soldering) caused the
VSWR alarm.
The cut-off rate of speech had been increased after device working :
Since the BMB900 MCPA was installed in the BTS, the drop-call had been
increased. After we dial-up test by phone in coverage area, we found that once
the signal occupied the TCH28. and signal path, the power level of TCH36
channel was dropped down. Then we went back to the BTS, exchanged the
BTS connect cables and found 6 dB discrepancy by handheld terminal test. At
last, we sent the TMB back to our company and found a semi-steel cable which
connected the duplexer and mixer was damaged.
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Maintenance --- Typical Case
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The BTS happened to lose coverage : After a TMB was installed, the
signal there became weak and there was nearly no call on BTS. Our engineer
used handheld terminal to test and found the forward power of the TMB is quite
low, but the VSWR is high. Then we opened the power amplifier and found that
the sampling load burned out and the ring isolator also burned out. We changed
it with a new power amplifier. The faulty was eliminated.
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Failure of remote gain change: After the BTS with TMB installed was
expanded, the gain can’t be adjusted through remote monitoring center. After an
on-the-spot inspection, we found that the manual dial-up switch couldn’t work
and the gain couldn’t be changed. Then we replaced the lamp boad, and
troubles resolved. So we made sure that the controlling chip in the lamp panel
was damaged.
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The state information of BMB can’t be read through remote
monitoring center: After the BMB was installed in the BTS, the TMB status
can be monitored by handheld terminal, but the remote monitor couldn’t work.
Then we replaced the modem, and the faulty was eliminated.
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•Applications --- Operation Contrast
Railway Coverage Application
Road Test (RT) before installation of MCPA
Before MCPA was employed in the region of
25371, as the picture, the signal coverage
along the railway is weak and small.
Road Test (RT) after installation of MCPA
After MCPA was installed in the region of
25371, as the picture, the coverage area along
the railway has been widened, and the speech
quality in this area has been improved a lot.
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Questions !
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