GB/T 15874-1995 General specification for trunked mobile communication system equipment
Some standard content:
ICS33.060.50
National Standard of the People's Republic of China
GB/T15874—1995
General specification for trunked mobile communication systemGeneral specification
for trunked mobile communication system1 Subject content and scope of application
GB/T15874—1995
This standard specifies the terminology, general technical requirements, technical requirements for system equipment, safety requirements and measurement methods, system test methods, environmental test requirements and test methods, reliability requirements and test methods, quality assessment rules, marking, packaging, transportation and storage requirements and test methods for trunked mobile communication system (referred to as trunked system). This standard applies to single-zone basic trunking systems with centralized control mode for land use. Multi-zone systems and trunking systems with other control modes can also be implemented as a reference.
2 Reference standards
GB3378 Automatic telephone exchange user signal mode GB6282 Interface parameters for 25~1000MHz land mobile communication network to access the public communication network through user lines GB9410 General technical specifications for mobile communication antennas GB12192 Measurement methods for mobile communication FM radio telephone transmitters GB12193 Measurement methods for mobile communication FM radio telephone receivers GB/T15844.1 General technical conditions for mobile communication FM radio telephones GB/T15844.2 Environmental requirements and test methods for mobile communication FM radio telephones GB/T15844.3 Reliability requirements and test methods for mobile communication FM radio telephones GB/T1584 4.4Quality Assessment Rules for FM Radiotelephones for Mobile CommunicationsGB/T15491Electrical Performance Requirements and Measurement Methods for Mobile Communications DuplexersGB/T13722
Technical Requirements and Measurement Methods for Mobile Communications Power SuppliesGB/T14013Transportation and Packaging of Mobile Communications EquipmentGB15842Safety Requirements and Test Methods for Mobile Communications EquipmentGB15539Technical System Specifications for Trunked Mobile Communications Systems3Terms
3.1Trunked Mobile Communications SystemsA mobile communications system in which multiple users (departments, groups) share a set of wireless channels and use these channels dynamically, mainly used for professional dispatch communications.
3.2Single Area System
A system covering a single wireless coverage area.
3.3Local Area Network
A multi-area trunked communications network consisting of more than two single area systems. Approved by the State Administration of Technical Supervision on December 22, 1995, and implemented on August 1, 1996
GB/T15874—1995
The regional network is managed by the regional controller (or regional switch). 3.4 Dispatcher
Equipment in the system that can command and manage mobile stations and fixed stations. Dispatchers are divided into wired dispatchers and wireless dispatchers. 3.5 Subscriber
General term for dispatchers and mobile stations.
3.6 Telephone interconnectiontelephoneinterconnectWired telephone users and wireless users in the system interconnect and communicate. 3.7 Telephone interconnectterminalInterface equipment that completes telephone interconnection.
3.8 Transmitter combinertransmittercombinerA device that feeds the power of multiple transmitters of a base station to the transmitting antenna of the base station. It mainly includes: isolator, cavity resonator, power mixer and impedance matching regulator.
3.9 Receiver multicupler A device that distributes the signal received by the base station receiving antenna to each receiver of the base station. The signal is usually amplified before the splitting to compensate for the splitter loss. The receiver splitter mainly includes: isolator, broadband low noise amplifier, filter and multiplexer. 4 General technical requirements of the system
4.1 System composition
It mainly consists of four parts: base station, system controller, dispatch station and mobile station. The base station consists of multiple base stations, antenna feed system and power supply. The mobile station is divided into groups (clusters), and each group has its own dispatch station. 4.2 Main equipment of the system
a. Base station: It consists of a transceiver and a power supply, with one base station for each channel. Antenna feed system: It includes transmitting antenna, receiving antenna, feeder, transmitter combiner and receiver splitter, etc. b.
System controller: mainly includes cluster control logic circuit, monitoring circuit, interface circuit with base station transceiver, telephone interconnector C.
and power supply.
Dispatching station: divided into wireless dispatching station and wired dispatching station. Wireless dispatching station: composed of transceiver, control unit, antenna, power supply and operating device; wired dispatching station: including interface unit connected to system control center and dispatching control unit; e. Mobile station: composed of transceiver, control unit, antenna and power supply In addition to the above basic equipment, system management terminal and other auxiliary equipment such as auxiliary receiver, conventional relay station and voice recording, billing and printing equipment can be added according to system design and user requirements. 4.3 System function
According to GB15539.
4.4 Working frequency band
800MHz frequency band;
Other frequency bands: to be determined.
4.5 Signaling
According to GB15539.
5 Technical requirements for system equipment
5.1 Technical requirements for system controller
5.1.1 Function
GB/T15874—1995
a. Complete the generation, coding, detection and various controls of signaling b. Realize the system functions specified in Article 4.3.
5.1.2 Electrical performance requirements
5.1.2.1 Wireless signaling coding and format:
According to GB15539.
5.1.2.2 Digital signaling clock frequency tolerance: 1X10-4. 5.1.2.3 The frequency tolerance of the subcarrier is specified by the product standard. 5.1.2.4 Maximum allowable frequency deviation: ±5kHz. 5.1.2.5
Requirements for connection with base stations:
Can connect 5 to 20 base stations;
Interface mode: 4-wire connection;
Interface level: The level of the signaling and audio signals sent to the transmitter is specified by the product standard. The crosstalk loss between each wired output port: greater than 50dB (300-3000Hz); The isolation between the audio ports from the transmitter to the receiver is at least 30dB (300-3000Hz). 5.1.2.6
Requirements for connection with PABX and PSTN:
Interface mode: User line interface;
Interface level: The audio signal level output to the wired telephone network is -4.5dBm/600Q. The audio signal level input from the wired telephone network is 0dBm/6002;
Audio bandwidth: 300~3000Hz
Audio response: The amplitude change relative to 1020Hz should be -0.2~+0.5dB in the range of 300~3000Hz; Other interface requirements are in accordance with GB6282
The user loop resistance, insulation resistance and line capacitance of the user line should comply with the relevant provisions of GB3378. 5.2 Base station technical requirements (working frequency band 800MHz) Transmitter electrical performance requirements
Carrier power: 25W/50W/75W/100W, adjustable or fixed; output impedance: 502;
Working mode: continuous;
Frequency tolerance: 2×10-6 (-25~+55℃)), emission category: 16KOF3E;
Adjacent channel power (ratio): ≥70dB;
Spurious RF component: ≤-70dB,
Audio bandwidth and distortion: bandwidth 300~3000Hz, audio distortion: <5%; audio response: +1~-3dB (relative to 6dB/oct pre-emphasis); residual FM: <-45dB.
Receiver electrical performance requirements
Reference sensitivity: ≤0.4μV (duplex sensitivity deterioration should be less than 3dB); RF input impedance: 50Q;
Frequency tolerance 2×10-(-25~+1055℃); Modulation reception bandwidth: >2×6kHz;
Adjacent channel selectivity: ≥75dB;
Spurious response immunity: ≥75dB;
Intermodulation immunity: ≥70dB;
Receiver conducted spurious radiation: <2μW;
Blocking: >95dB;
GB/T15874—1995
Relative audio intermodulation product level: specified by the product standard; i
Audio bandwidth and distortion: bandwidth 300~3000Hz, audio distortion <5%; Audio response: +1~-3dB (relative to 6dB/octave de-emphasis). 5.3 Technical requirements for antenna and feeder system
Electrical performance requirements for base station transmitting antenna and receiving antenna a.
Frequency range: 806~866MHz;
Antenna gain: 6~12dB(d) (omnidirectional), 10~12dB (directional); Impedance: 50Q;
Polarization: vertical;
Voltage standing wave ratio: ≤<1.5;
Directional pattern: specified by the product standard,
Maximum input power: specified by the product standard. Electrical performance requirements for base station transmitter combiners
Frequency range: 851~866MHz;
Insertion loss: specified by product standards,
Isolation: ≥60dB between transmitting branches (at 500kHz interval): Reverse transmission loss: between antenna and transmitter, ≥50dB Voltage standing wave ratio: <1.5,
Port characteristic impedance: 50;
Maximum input power: specified by product standards. Electrical performance requirements for base station receiver splitters
Frequency range: 806~821MHz,
Bandwidth: 5MHz, 10MHz, 15MHz;
Gain: specified by product standards;
Voltage standing wave ratio: <1.5,
Isolation between ports: >30dB;
Port characteristic impedance: 502.
5.4 Technical requirements for wireless dispatch station and mobile station (working frequency band: 800MHz) 5.4.1
Electrical performance requirements for transmitter
Carrier power: 10W/15W/25W (handheld station 1W/2W/3W); RF output impedance: 50Ω;
Frequency tolerance: 3×10-6 (-25~+55℃); Emission category: 16KOF3E;
Adjacent channel power (ratio): ≥65dB (handheld station: <2.5μW); Spurious RF component: ≤-70dB (handheld station: <2.5μW); Residual FM: <-40dB;
Audio distortion: ≤5% (handheld station: ≤7%); Audio response: ±3dB (relative to 6dB/oct pre-emphasis): Transmitter start-up time: <20ms.
5.4.2 Receiver electrical performance requirements
Reference sensitivity: <0.4μV, (duplex sensitivity deterioration should be less than 3dB); b.
RF input impedance: 50Q;
GB/T15874—1995
Frequency tolerance: 3×10-(-25~+55℃); Modulation reception bandwidth: >2×6kHz;
Adjacent channel selectivity: ≥70dB (handheld station: ≥60dB); Spurious response immunity: ≥70dB (handheld station: >60dB): Intermodulation immunity: ≥70dB (handheld station: ≥60dB) Audio output power: specified by the product standard; Audio distortion: <7%.
5.4.3 Technical requirements for control unit
5.4.3.1 Basic functions
Cooperate with system controller to realize system functions in Article 4.3; complete signaling generation, detection, channel scanning and various control functions, and have sound and light indications such as ringing, ringback, busy tone, and prompt tone for dialing keys.
Electrical performance requirements
Signaling coding and format shall comply with GB15539; digital signaling clock frequency tolerance: 1X10-, subcarrier frequency tolerance shall be specified by product standards Maximum allowable frequency deviation: ±5kHz;
Signaling level sent to transmitter: specified by product standards, e.
Level output from receiver to decoder: specified by product standards. f.
5.4.4 Technical requirements for antenna and duplexer
Antenna technical requirements shall comply with GB9410. Duplexer technical requirements shall comply with GB/T15491. 5.5 General requirements for structure and process
Refer to the provisions of GB/T15844.1 on equipment structure and process requirements. Antenna structure shall comply with the provisions of GB9410. 5.6 Technical requirements for power supply
Power supply voltage: 220V (AC), 50Hz; 9.6, 12, 24, 48, 60V (DC) Technical requirements for power supply of various equipment in the system shall comply with the provisions of GB/T13722 5.7 Technical requirements for wired dispatching desk and auxiliary equipment shall be specified by product standards.
6 Electrical performance measurement method for basic equipment of the system
6.1 Test conditions
6.1.2 Unless otherwise specified, the electrical performance tests of the main equipment of the system shall be carried out under standard test atmospheric conditions (15℃～35℃). 6.1.2 When conducting various electrical performance tests, shielding measures shall be adopted to prevent external interference from affecting the effect and accuracy of the test. 6.1.3 The accuracy of all test equipment and measuring instruments used shall meet the measurement requirements of the equipment under test and must be calibrated within the measurement cycle.
6.2 Electrical performance measurement methodbzxz.net
6.2.1 Measuring instruments
Measuring instruments specified in GB12192;
Measuring instruments specified in GB12193;
Measuring instruments specified in GB9410
Measuring instruments specified in GB/T15491;
GB/T15874—1995
e.Measuring instruments specified in GB/T13722. 6.2.2 System controller electrical performance measurement
6.2.2.1 Digital signaling clock frequency value
Measurement steps:
a. Use a frequency meter to measure the clock frequency value;
b. The absolute value of the difference between the frequency value measured in item a and the nominal value of the clock frequency is the frequency deviation. This deviation should be less than the tolerance, and the frequency meter accuracy should be ten times higher than the tolerance of the measured frequency.
6.2.2.2 Subcarrier frequency value
Measurement steps:
a. Connect the equipment and instruments according to Figure 1:
Figure 1 Measurement configuration of subcarrier frequency value
1—System controller under test 2—Digital frequency meter; 3—Equivalent load with modulator input impedance; 4—Audio level meter Turn on the power supply to make the system controller work normally b.
Make the system controller generate a modulation signal connected to the "0" code, and record the frequency value fod counted by the digital frequency meter at this time.
Make the system controller generate a modulation signal with continuous "1" code, and record the frequency value fod counted by the digital frequency meter at this time. The difference between f1 and the nominal frequency of the subcarrier is the subcarrier frequency deviation. e.
6.2.2.3 Steps for measuring the signaling level sent from the controller to the base station transmitter:
Connect the equipment and instruments according to Figure 1;
Turn on the power supply to make the system controller work normally. Make the system controller continuously generate digital signaling signals. The reading of the audio level meter is the signaling level sent to the transmitter. c.
6.2.2.4 Steps for measuring the interface level and audio response of the system control transmission path:
a. Connect the equipment and instruments according to Figure 2. Select the output impedance of the audio signal generator and the input impedance of the audio frequency selection meter to be 6002; 1
With full
Without war box
Figure 2 Configuration for measuring the controller signaling level
1—audio signal generator, 2—system controller under test, 3 audio frequency selection level meter b. Turn on the power supply to make the system controller work normally; c. Adjust the frequency of the audio signal generator to 1020Hz and the output level to 0dBm. Record the audio frequency selection level meter reading Po at this time, which is the audio signal interface level sent from the system controller to the base station repeater transmitter; d. Adjust the audio signal generator frequency f to 300, 400, 600, 1000, 1200, 1600, 2000, 2400, 2700, 3000Hz, and keep the output level at 0dBm, and record the audio frequency selection level meter reading Pte at each frequency point f.The audio response of the transmission path in the system controller is calculated by the following formula: Le relative = 0-P,
GB/T15874-1995
Wherein: L relative - the output level at the frequency f point relative to the output attenuation value of 1020Hz, dB; Pt - the output level at the frequency f point, dBm/600Q. 6.2.2.5 Measurement steps of the audio port isolation from the transmitter to the receiver;
a. Connect the equipment and instruments according to Figure 3. Turn the connecting line switch to the wireless transmitting end, adjust the instrument output and input impedance to 6002; no warping end
with or without
no entertainment increase
Figure 3 Measurement configuration of controller audio port isolation 1—audio signal generator; 2—system controller under test; 3—audio frequency selection level meter b.
Turn on the power to make the system controller work normally; adjust the audio signal generator frequency and the audio frequency selection level meter to 1020Hz, and adjust the audio signal generator output level to 0dBm. Record the audio frequency selection level meter reading Pr at this time; turn the connection line switch to the wireless receiving end, and record the level meter reading PRd.
The frequency of the audio signal generator changes from 300~3000Hz, and find the maximum PR value PRMAXe.
The isolation between the transmitter and the receiver is Pr
-PRMAXdB
6.2.2.6Measurement steps for crosstalk loss between each wired output port:
Connect the equipment and the instrument according to Figure 4;
Wireless end
Relay end
Figure 4 Measurement configuration of crosstalk loss between wired output ends of each controller 1—audio signal generator; 2—audio frequency selection level meter: 3 Turn on the power of the system controller under test to make the system controller work normally, b.
c. The audio signal generator outputs an audio signal with a frequency of 1020Hz and a level of 0dBm (the output impedance is 600Q); d. Record the level of the audio level meter receiving frequency of 1020Hz (the impedance of the level meter is 600Ω), which is the crosstalk loss between the two wired output ports.
6.2.2.7 Steps for measuring the audio response of the interface with PABX or PSTN:
Connect the equipment and instruments according to Figure 5, and select the input impedance of the audio frequency selective level meter and the output impedance of the audio signal generator as a.
Figure 5 Measurement configuration of the audio response of the controller and the wired network interface 1—audio signal generator; 2—system controller under test; 3—audio frequency selective level meter Turn on the power supply to make the system controller work normally, b.
Adjust the frequency of the audio signal generator and the frequency of the audio frequency selective level meter to 1020 Hz, and then adjust the audio signal generator output level to make the audio frequency selection meter read -4.5dBm/600Q, record the output level of the audio signal generator at this time P/(dBm/6007
GB/T15874—1995
), which is the level output from the base station receiver to the system controller. The audio signal generator frequency f is adjusted to 300, 400, 600, 1000, 1200, 1600, 2000, 2400, 3000Hz respectively, and keep the output level P. unchanged, record the reading of the audio frequency selection level meter at each frequency point P/dBm/600Q). The audio response can be calculated by the following formula:
L relative = — 4. 5 — P
The attenuation value of the output level at a frequency point f relative to the output level at 1020Hz, dB; In the formula: L relative
The output level at a frequency point, dBm/600Q. 6.2.3 The electrical performance measurement of the transmitter and receiver of the base station, wireless dispatch station, mobile station and fixed station shall be measured in accordance with the provisions of GB12192 and 12193. 6.2.4 Performance measurement of the control unit of the dispatch station, mobile station and fixed station a. The measurement steps of the digital signaling clock frequency value are the same as those in Article 6.2.2.1; the measurement steps of the subcarrier frequency value are the same as those in Article 6.2.2.2; b.
c. The measurement principle of the signaling level sent to the transmitter is the same as that in Article 6.2.2.3. 6.2.5 The electrical performance measurement of the base station antenna
shall be measured in accordance with the provisions of Article 3.3 of GB9410.
6.2.6 Measurement of electrical performance of base station transmitter combiner 6.2.6.1 Isolation between transmitter branches
Measurement steps:
Connect the equipment and instruments according to Figure 6, and connect the antenna port ANT to point Q:; a.
Figure 6 Measurement configuration of isolation between transmitter branches Txn
1-RF power signal generator, 2-variable attenuator (as needed), 3-RF spectrum analyzer; 4-standard output load; 5-Tested transmitter combiner (2)
b: Connect point 01 and point 0? directly. Adjust the frequency of the RF power signal generator to the operating frequency of transmitter branch 1 (T), adjust its output and the attenuation of the variable attenuator, so that the spectrum analyzer obtains a certain appropriate input level, and record the level P1/dBm and the attenuation of the attenuator A13
c. Connect point Q1 to the transmitting branch T port of the combiner, and point Q2 to the transmitting branch T2 port. The output level of the RF power signal generator maintains the value of step b, and adjusts the attenuator to make the spectrum analyzer obtain an appropriate input level, and record the level P2/dBm and the attenuation of the attenuator A2,
d. According to the records in steps b and c, the attenuation value A is calculated as the isolation of Tx-Tx as follows: A=P1-P2+A1-A2
Where: Pi - the level reading recorded in step b, dBm; P2 - the level reading recorded in step c, dBm; Ar
- the attenuation recorded in step b, dB
A2 - the attenuation recorded in step c, dB. According to the above steps, the isolation between each branch is measured, and the smallest value is the isolation between the transmitting branches. e.
·（3）
6.2.6.2 Reverse transmission loss
Measurement steps:
GB/T15874—1995
a. Connect the equipment and instruments according to Figure 6, and connect the transmitter branch Tx2 to point Q2; read P1/dBm and A1 according to the method in step b of 6.2.6.1; b.
c. Connect point Q1 to the antenna port of the combiner, and point Q2 to the port of the transmitting branch Tx, and read P2/dBm and A2* according to the method in step c of 6.2.6.1
According to the records of steps bc, calculate the A value from the antenna to the transmitting branch Tx (ANT-Tx1) according to the principle of 6.2.6.1; according to steps b, c, and d, calculate the A value from the antenna to other branches, and the smallest value is the isolation from the antenna to the transmitter branch. e.
6.2.6.3 Insertion loss
Measurement steps:
Connect the equipment and instruments according to Figure 6, and connect the transmitter 2 branch (Tx2) to point Q3; a.
b. Read P1/dBm and A13 according to the method in step b of 6.2.6.1. Connect point Q1 to the port of the transmitting branch T of the combiner, and point Q2 to the antenna port ANT of the combiner. The output level of the signal generator C.
maintains the value of step b, adjusts the attenuator, so that the spectrum analyzer obtains the level to maintain the P1 value, and records the attenuation of the attenuator at this time A23
According to the records of steps b and c, the insertion loss A of the transmitting branch Tx is obtained by the following formula: A=AL
Wherein: A1——the attenuation recorded in step b, dBA2—the attenuation recorded in step c, dB.
e. According to the above steps, calculate the transmission loss A value from Tx2, Tx3....T to the antenna ANT, where the largest loss value is the combiner insertion loss.
6.2.6.4 Voltage standing wave ratio (transmitter combiner) measurement steps:
a. Connect the equipment and instruments according to Figure 7;
Figure 7 Measurement configuration of voltage standing wave ratio of transmitter combiner 1 Sweeper: 2—standing wave bridge: 3—matching load: 4 Combiner under test Trr
b. Separate the Q point from the port of the transmitter branch T, adjust the output signal frequency of the sweeper to the specified operating frequency of the transmitting branch Tx, and measure and record its open circuit reflected power level P1/dBm on the sweeper; c. Connect point Q to the port of the transmitter branch Tx, measure and record the reflected power level P2/dBm, d. Calculate the return loss value:
A=P1-P2
-the power level recorded in step b, dB; where: Pi
-the power level recorded in step c, dB. P2
From the A/dB value, look up the conversion table of return loss value and standing wave ratio to obtain the standing wave ratio value of the transmitting branch Tx; e.
(5)
GB/T15874—1995
f.According to the methods of steps b, c, d, and e, measure the VSWR value of each transmitting branch, among which the maximum value is the VSWR of the combiner. Note: Under the condition of ensuring the measurement accuracy, the VSWR can also be measured by other methods. 6.2.7 Measurement of electrical performance of base station receiver splitter 6.2.7.1 Isolation between ports
Measurement steps:
a. Connect the equipment and instruments according to Figure 8;
Figure 8 Measurement configuration of isolation between ports of receiver splitter Ruh
1-RF signal generator; 2-variable attenuator (as needed), 3-RF spectrum analyzer, 4-standard output load; 5-receiver splitter under test b. Directly connect point Q1 with point Q2, adjust the frequency of the signal generator to the operating frequency of the receiver branch Rx, adjust the output of the signal generator and the attenuation of the attenuator, so that the spectrum analyzer obtains a certain reduction A1$
appropriate input level, and record the level P1/dBm and attenuation c. Connect point Q1 to the receiving branch Rx port of the splitter, and point Q2 to the receiving branch Rx2 port of the splitter. Maintain the frequency and output level of the signal generator at the values of step b, and adjust the attenuator appropriately so that the spectrum analyzer has a suitable input level, record the reading P2/dBm of the spectrum analyzer and the attenuation A2 of the attenuator; d. The isolation A between the two branches of the splitter Rxi and Rx2 is calculated as follows: A=P-P2+A-A2
Where: P1-
-the level value recorded in step b, dBm, P2-the level value recorded in step c, dBm; Ar-the level value recorded in step b, dB,
A2-the level value recorded in step c, dB (6)
e. According to the methods of steps b, c, and d, measure the isolation A value between each receiving branch, where the smallest A value is the isolation between the receiving branches.
6.2.7.2 Voltage Standing Wave Ratio (receiver splitter) measurement steps:
Connect the equipment and instruments according to Figure 9;
GB/T15874—1995
Figure 9 Measurement configuration of voltage standing wave ratio of receiver splitter Appendix.
1—sweeper; 2—standing wave bridge; 3—matching load 4—receiver splitter under test Measure the open circuit reflection power according to the method in step b of 6.2.6.4. The power level P1/dBm; measure the reflected power level P2/dBm of the receiving branch R according to the method of step c of 6.2.6.4; calculate the return loss value A/dB according to the method of step d of 6.2.6.4, and check the conversion table of return loss value and standing wave ratio from the A/dB value to obtain the standing wave ratio value of the receiving branch Rx1; measure the standing wave ratio value of each branch according to the methods of steps b, cd, and e, and the maximum value is the voltage standing wave ratio of the receiver splitter. f.
Note: Other measurement methods can also be used under the same conditions of ensuring the same measurement accuracy. 6.2.7.3 Gain
Measurement steps:
Connect the equipment and instruments according to Figure 10;
Figure 10 Measurement configuration of receiver splitter gain
1-RF signal generator; 2-matching load; 3-RF voltmeter; 4-receiver splitter under test Connect Q1 point and Q2 point directly, adjust the signal generator frequency to the working frequency of the receiving branch (Rx1), and adjust the output level b.
Make the RF voltmeter obtain a certain appropriate input level, and record the RF voltmeter reading V1/dBuV; c. Connect Q1 point to the antenna port ANT, and Q2 point to the receiving branch Rx2 port. Keep the frequency and output level of the signal generator unchanged at the values in step b, and record the RF voltmeter reading V2/dBuV; d. Calculate the gain from the antenna to the Rx branch port A/dB#A=VV2
Where: Vi——the level recorded in step b, dBuV; V2—the level recorded in step c, dBuV.
According to the methods in steps b, c, and d, measure the gain from the antenna port to each receiving branch, the minimum of which is the gain of the receiver splitter. 6.2.8
Electrical performance measurement of power supply equipment
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