This standard specifies the technical requirements and test methods for TACS-based cellular mobile station transmitters and receivers in the 900MHz frequency band of the public network. This standard applies to the network entry inspection of analog cellular mobile station transceivers in the 900MHz frequency band, and is also applicable to the inspection of such equipment by production and operation departments. GB/T 15942-1995 Technical requirements and test methods for mobile stations in the 900MHz public mobile communication system GB/T15942-1995 Standard download decompression password: www.bzxz.net

ICS33.060.50
National Standard of the People's Republic of China
GB/T15942—1995
Technical requirement and testing methods for mobilestationaccess to900 MHzpublic mobiletelecommunicationsystem
Published on December 21, 1995
State Administration of Technical Supervision
Implementation on August 1, 1996
National Standard of the People's Republic of China
Technical requirement and testing methods for mobilestationaccess to 900 MHz public mobiletelecommunication system
1 Subject content and scope of application
GB/T15942—1995
This standard specifies the technical requirements and test methods for TACS-based cellular mobile station transmitters and receivers in the 900MHz frequency band of the public network.
This standard applies to the network entry inspection of analog cellular mobile station transceivers in the 900MHz frequency band, and is also applicable to the inspection of such equipment by production and operation departments.
2 Reference standards
GB2423.1 Basic environmental test procedures for electric and electronic products Test A: Low temperature test method GB2423.2 Basic environmental test procedures for electric and electronic products Test B: High temperature test method GB2423.3 Basic environmental test procedures for electric and electronic products Test C: Steady-state damp heat test method British Total Access Communication System (TACS) Mobile and Fixed Station Technical Specifications E1A/1S—19—B
3800MHz Cellular User Unit Recommended Minimum Standards 3 Test Conditions
3.1 Normal Test Conditions
Temperature: +15℃~+35℃
Humidity: 20%~75%
Air Pressure: 86kPa~106kPa
Power supply: The DC power supply voltage is ±2% of the value specified by the manufacturer. The AC power supply voltage is 220V ±2%, and the AC power supply frequency is 50Hz±1Hz. 3.2 Extreme test conditions
Temperature: -30℃~+60℃
b. Power supply: DC power supply voltage is 1.3 times and 0.9 times the value specified by the manufacturer; AC power supply voltage is 220V±10%, and AC power supply frequency is 50Hz±1Hz. Note: According to TACS regulations, only the receiver's "usable sensitivity" indicator is allowed to relax requirements under extreme test conditions. 3.3 Other test conditions and regulations
3.3.1 Selection of test channels
a. For single-channel test, select the middle channel; b. For multi-channel test, select channels evenly within the frequency band. Approved by the State Administration of Technical Supervision on December 21, 1995 and implemented on August 1, 1996
3.3.2 The nominal impedance of the test signal added to the input of the receiver is 50Ω;
GB/T15942—1995
b. The test signal level refers to the level generated on the standard load (50Ω) of -50dBmc.
Standard test modulation refers to a 1kHz sinusoidal input signal at a certain The modulation level produces a carrier frequency deviation equal to 60% of the maximum allowable frequency deviation. The harmonic distortion of the sinusoidal input signal should be less than 1%. 3.3.3 Standard load
a. The standard output load of the transmitter is a 50α non-radiative resistive load that can withstand the carrier output power of the transmitter under test. b. The standard output load of the receiver is a resistive load with a resistance equal to the normal operating load of the receiver. 3.3.4 Signal-to-noise ratio (SINAD)
The signal-to-noise ratio is defined as the ratio of the power sum of the signal, noise and distortion on the standard test load to the power sum of the noise and distortion: S+N+D/N+D
Where: 8 is the useful audio signal generated by the standard test modulation: N is the noise under the standard test modulation,
D is the standard test modulation Distortion under control.
Usually expressed in decibels (dB), the standard signal-to-noise ratio is specified to be 20dB. 3.3.5 Equipment control
During the test, the equipment provided must have the following functions: a.
Can be set according to the specified power level, and the carrier can be turned on/off at all power levels. It can be tuned to any channel assigned in the specified frequency band. It can control the receiving and transmitting audio mute circuits. When testing the receiver, the mute circuit should be able to be cut off; c.
Should be able to control the compressor and expander. When testing the receiver signal-to-noise ratio, the compressor and expander should be able to be cut off; d.
When there is no external modulation on the transmitter and when testing the maximum frequency deviation, the monitoring tone, signaling tone and broadband data signal must be turned off; e.
f. The power supply and equipment of the crystal constant temperature box The power supply of other parts should be able to be controlled separately. 3.3.6 Establishing a calling procedure
After the device under test is connected to the test instrument, the calling procedure is first carried out, and then various tests are carried out. The process is as follows: the device under test and the test instrument are powered on, and the device under test is registered in the test instrument. After the test instrument confirms, it sends a command to the device under test to carry out a calling test, and the calling is completed; after the test instrument receives it, it orders the device under test to hang up and wait. Then carry out the called test. At this point, the procedure for establishing a call is completed, and the various indicators of the device under test can be tested. 4 Technical requirements and test methods for transmitters
4.1 Carrier frequency error
4.1.1 Definition
The carrier frequency error of a transmitter refers to the difference between the measured unmodulated carrier frequency and its nominal frequency (f). It is expressed in units of 10-' or Hertz (Hz).
4.1.2 Index
±2.5×10-* or ±f×2.5×10-(Hz) 4.1.3 Test method
a. The block diagram of the test circuit and the instruments used are shown in Figure 1.
Figure 1 Carrier frequency error test block diagram
GB/T15942—1995
The transmitter under test is on the specified channel and works without modulation; the carrier frequency of the transmitter under test is measured with a frequency meter. The difference between the measured frequency and the nominal frequency of the transmitter under test is the carrier frequency error of the transmitter on the specified channel; d.
Repeat the above measurement on other specified channels. e.
4.2 Monitoring tone frequency error
4.2.1 Definition
The monitoring tone (SAT) frequency error refers to the difference between the monitoring tone frequency retransmitted by the transmitter and its nominal frequency. The nominal frequencies are 5970, 6000, 6030 Hz, which are out-of-band audio tones used for communication between base stations and mobile stations. 4.2.2 Specifications
±10 Hz.
4.2.3 Test method
a. Connect the test equipment as shown in Figure 2;
Turn on the RF signal generator and the audio signal generator; c.
The RF signal generator sends out the receiving frequency corresponding to the transmitting frequency of the device under test, and the audio signal generator sends the monitoring audio frequency (any one of 5970, 6000, 6030Hz); turn on the device under test and demodulate the monitoring audio with the modulation analyzer; d.
Production prognosis number
Generator
RF signal
Generator
X-link
(or network distance from the station>
|Training equipment
Figure 2 Monitoring Test block diagram for frequency error of the monitoring tone
Use a frequency meter to record the frequency of the monitoring tone: e.
f. The difference between the measured frequency and its nominal frequency is the frequency error of the monitoring tone. g. For the other two monitoring tones, measure according to \b", "c", "d", "e", "". 4.3 Signaling tone frequency error
4.3.1 Definition
Bandwidth meter
Signaling tone is the signaling for the mobile station to communicate with the base station, and its frequency is 8kHz. The signaling tone frequency error is the difference between the measured signaling tone frequency and its nominal value.
4.3.2 Indicator
±1Hz.
4.3.3 Test method
a.Connect the test equipment as shown in Figure 3;
Set up the transmitter
Thank the modulation analyzer
3 Signaling tone frequency error test block diagram
Turn on the transmitter;
Turn on the signaling tone and use it to modulate the carrier of the specified channel; Frequency meter
GB/T15942—1995
Use the modulation analyzer to demodulate the signal; d.
Use the frequency meter to measure the signaling tone frequency;
f. The difference between the measured frequency and its nominal value is the frequency error of the signaling tone. 4.4 Rated carrier output power
4.4.1 Definition
The rated carrier output power of the transmitter refers to the effective power delivered to the standard output load by the transmitter carrier when it is not modulated. 4.4.2 Indicators
The rated carrier output power should be the effective radiated power minus the antenna gain. The effective radiated power should meet the values ​​given in Table 1. Table 1
Power level
Mobile station level
Within the nominal value dB range.
4.4.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 4. a.Www.bzxZ.net
Micro-test transmitter
Effective radiated power, dBW
Power meter
Figure 4 Carrier rated output power test block diagram b.
Turn on the transmitter and make it work on the specified channel without modulation for 5
The power number indicated on the power meter is the carrier rated output power of the transmitter under test on the specified channel. c.
If necessary, the measurement can be repeated on other channels configured by the transmitter. d.
4.5 Maximum allowable frequency deviation
4.5.1 Definition
The maximum allowable frequency deviation of a transmitter is the maximum difference between the instantaneous frequency of the modulated carrier signal and the unmodulated carrier frequency. 4.5.2 Specification
±9.5kHz.
4.5.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 5; a.
Audio signal generator
GB/T15942—1995
Tested transmitter
Audio level meter
Figure 5 Block diagram of maximum allowable frequency deviation test
Turn on the transmitter and make it output at rated power on the specified channel. b.
Period of test
c. The frequency of the audio signal generator is 1kHz. Adjust its output level so that the frequency deviation meter indicates ±5.7kHz, and write down the level value U (dB) of the audio level meter;
d. Adjust the output level of the audio signal generator so that the level value of the audio level meter is 20dB higher than U, and write down the frequency deviation value at this time. This frequency deviation is the maximum allowable frequency deviation of the transmitter. Note: During the test, the monitoring tone, signaling tone and broadband data signal should be cut off. 4.6 Monitoring audio deviation
4.6.1 Definition
Monitoring audio deviation refers to the use of any of the three monitoring audio frequencies. 4.6.2 Indicator
±1.7kHz±10%.
4.6.3 Test method
The test circuit block diagram and the instrument used are shown in Figure 6a.
b. Same as 4.2.3b
Same as 4.2.3c
Modulate the carrier, and the resulting frequency deviation is called monitoring audio deviation. Turn on the device under test and use the frequency deviation meter to test the frequency deviation. The frequency deviation is the monitoring audio deviation. 4.7 Signaling audio deviation 4.7.1 Definition First frequency signal Generator Transmitter signal Generator (or receiver) Monitored audio deviation Test block diagram Frequency signaling Signaling audio deviation refers to the frequency deviation obtained by modulating the transmitter carrier with signaling tone. 4.7.2 Indicator ±6.4kHz±10%.
4.7.3 Test method
a. The block diagram of the test circuit and the instruments used are shown in Figure 7. 5
Turn on the transmitter:
Test transmitter
GB/T15942—1995
Figure 7 Signaling audio deviation test block diagram
Use the signaling tone to modulate the carrier on the specified channel of the transmitter; c.
d. The frequency deviation measured by the frequency deviation meter is the signaling audio deviation. 4.8 Broadband data frequency deviation
4.8.1 Definition
Broadband data refers to the signaling that communicates between the mobile station and the base station. Its transmission rate is 8kbit/s. The broadband data stream is used to modulate the carrier, and the frequency deviation obtained is the broadband data frequency deviation. 4.8.2 Indicators
±6.4kHz±10%.
4.8.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 7. Turn on the transmitter;
Modulate the transmitter carrier with 8kbit/s data; c
d. The frequency deviation measured by the frequency deviation meter is the broadband data frequency deviation. 4.9 Modulation stability
4.9.1 Definition
Modulation stability refers to the ability of the transmitter to generate and maintain a fixed frequency deviation. The frequency deviation should meet the following requirements:
Maximum allowable frequency deviation: ±9.5kHz;
Data (DATA): ±6.4kHz;
Monitoring tone (SAT): ±1.7kHz;
Signaling tone (ST): ±6.4kHz.
4.9.2 Index
On any designated channel, when the temperature range is -20℃～+50℃ and the supply voltage changes by ±10%, it should not exceed ±10% of the above frequency deviation value; when the temperature range is -30℃~+60℃ and the supply voltage changes by ±20%, it should not exceed ±15% of the above frequency deviation value. 4.9.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 5, Figure 6 and Figure 7 respectively; a.
Turn on the transmitter and compressor under the above temperature and voltage conditions; b.
Modulate the carrier of the designated channel with 1kHz single tone, signaling tone, monitoring tone and data signal respectively; c
Test the frequency deviation under the above conditions respectively.
4.10 Modulation frequency deviation limit
4.10.1 Definition
The modulation frequency deviation limit of the transmitter refers to the ability of the internal circuit of the transmitter to limit its ability to produce a frequency deviation value exceeding the maximum allowable value. 4.10.2 Index
≤9.5kHz.
4.10.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 5. b.
Measure the maximum allowable frequency deviation according to Section 4.5.3. c.
Change the modulation signal frequency from 300 to 3000Hz, and observe the indication of the frequency deviation meter. It should not exceed the specified value within this frequency range.
4.11 Spurious emission
4.11.1 Definition
GB/T15942—1995
The spurious emission of a transmitter refers to the emission of discrete frequencies other than the carrier and the sideband determined by the modulating signal when the carrier of the transmitter is modulated by the standard test.
4.11.2 Indicators
Transmitter working state: <-24dBm;
Transmitter waiting state: <-47dBm.
4.11.3 Test method
a. The block diagram of the test circuit and the instruments used are shown in Figure 8. The transmitter works without modulation of its carrier, adjust the spectrum analyzer to the nominal carrier frequency specified by the transmitter, so that the peak level of the carrier is displayed on the 0dB line on the screen. The frequency of the audio signal generator is 1kHz, and its output level is adjusted so that the frequency deviation meter indicates ±5.7kHz. The transmitter is in the waiting state, and the above test is repeated. 4.12 Broadband spectrum noise suppression
4.12.1 Definition
Broadband spectrum noise suppression refers to the ability to suppress the interference energy generated by the transmitter's internal noise in the transmission spectrum sideband. 4.12.2 Indicators
>26dB above ±16kHz from the carrier frequency; ±37.Above 5kHz:>45dB;
±50kHz and above:>60dB.
Test method
The block diagram of the test circuit and the instruments used are shown in Figure 8. Turn on the transmitter and turn off the compressor.
Modulate the carrier with a 1kHz single tone to generate a frequency deviation of ±5.7kHz, and record the modulation level U. Modulate the carrier with a 2500Hz sinusoidal signal, and the modulation level is 20dB higher than U; turn off the modulation signal, modulate the carrier with a 6000Hz monitoring tone (SAT), and generate a peak frequency deviation of ±1.7kHz; modulate the carrier with d and e at the same time, monitor the transmitter spectrum with a spectrum analyzer and record it, modulate the carrier with a broadband data signal to generate a frequency deviation of ±6.4kHz, monitor and record it on the spectrum analyzer, modulate the carrier with a monitoring tone (SAT) and a signaling tone (ST), respectively, and generate peak frequency deviations of ±1.7kHz and ±6.4kHz, respectively, then turn on SAT and ST at the same time to modulate the carrier, and monitor and record it with a spectrum analyzer: i. Check the readings on the above spectrum analyzer, which should meet the index requirements. 4.13 Modulation distortion
4.13.1 Definition
GB/T15942—1995
Transmitter modulation distortion refers to the distortion generated after the audio signal is processed by the audio circuit and the radio frequency circuit. That is, the ratio of the root mean square value of the distorted signal excluding the fundamental component to the root mean square value of the full signal, expressed as a percentage. This distorted signal includes harmonic components, non-harmonic components and power supply ripple.
4.13.2 Index
<5%.
4.13.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 9;
Generator
Analysis path
Block diagram of transmitter modulation distortion test
Turn on the transmitter and the compressor;
Noise generator
Network
Distortion meter
Adjust the audio signal generator to output a 1kHz single tone to modulate the carrier, generating a frequency deviation of ±2.3kHz, c
d. The distortion measured by the distortion meter is the transmitter modulation distortion. 4.14 Hum and noise
4.14.1 Definition
Hum and noise refers to the ratio of the audio output of the transmitter under modulation to the audio output under unmodulation. 4.14.2 Index
>32 dB.
4.14.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 10.
Signal
Generator
Audio
RF signal
Dual uplink or
hybrid network)
Throttle system
Analysis equipment
Go to add year
Figure 10 Block diagram of hum and noise test
Turn on the device under test, turn on the transmitter compressor, b.
Calibration network
Frequency meter
Audio signal generator (1) Output 1kHz audio to modulate the carrier Control, produce ± 5.7kHz frequency deviation, and repeat 6kHz monitoring tone according to the method of 4.6.3, produce ± 1.7kHz frequency deviation; record the level U13 indicated by the audio level meter
Remove the modulation signal of the device under test, and record the level U2 indicated by the audio level meter; e.
Hum and noise are:
U1-U2(dB)
4.15 Carrier off
4.15.1 Definition
GB/T15942—1995
Carrier off refers to the carrier output power at the transmitter antenna port when the transmitter is turned off. 4.15.2 Index
<-60dBm.
4.15.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 11; a.
Test equipment
Figure 11 Carrier shutoff test block diagram
Turn on the transmitter under test and the test instrument, and make the transmitter under test output the specified level of carrier power, b.
At this time, the power indicated on the spectrum analyzer is P
d. Turn off the transmitter under test and observe the carrier output power with the spectrum analyzer, which should be lower than -60dBm. 4.16 Audio channel silence
4.16.1 Definition
Audio channel silence refers to the ability of the transmitter to control the audio channel to be cut off during the transmission of broadband data. 4.16.2 Index
>40 dB.
4.16.3 Test method
a. The block diagram of the test circuit and the instruments used are shown in Figure 12. The frequency signal
generator
analyzer
heart card
audio channel silence test block diagram
Turn on the transmitter and the compressor;
Use the audio signal generator to output a 1kHz single tone to modulate the carrier to produce a peak frequency deviation of ±5.7kHz, and record the reading of the audio level meter Uo.
d. Turn on the silence circuit and record the reading of the audio level meter U1e. The difference between U and Ui is the audio channel silence. 4.17 Compression
4.17.1 Definition
Compression means that the transmitter voice processing circuit includes a compression part with a compression ratio of 2:1. Within its working range, for a 2dB change in the input signal level, the nominal value of the change in output level after the 2:1 compressor is 1dB. 4.17.2 Specification
When the input level changes in the range of +25dB to -30dB, the output should change according to its nominal 2:1 compression ratio, and the tolerance is ±0.5dB.
4.17.3 Test method
a. The block diagram of the test circuit and the instruments used are shown in Figure 13; 9
Audio signal
Generator
GB/T15942—1995
Set up transmitter
Policy system
Analysis according to
Voice amplifier
Figure 13 Compression test block diagram
b. Turn on the transmitter, turn on the compressor,
Electric half card
c. Audio signal generator The generator outputs a 1kHz single tone to modulate the carrier, generating a peak frequency deviation of ±2.3kHz. At this time, the audio level meter readings Ui and U2 are the reference level, recorded as 0dB. Change the input audio signal level U1, increase it from 0dB, with a step length of 2dB, until +25dB, and record the output level U23d.
e Reduce the input signal level U1 from 0dB, with a step length of 2dB, until -30dB, and record the output level U23f. The levels recorded in d and e should meet the index requirements. 5 Technical requirements and test methods for receivers
5.1 Usable sensitivity
5.1.1 Definition
The usable sensitivity of a receiver refers to the minimum RF signal required at the receiver input when the signal-to-noise ratio at the receiver audio output is 20dB and the audio output power is at least 50% of the rated power. 5.1.2 Index
<-113dBm (this index is allowed to be relaxed by 3dB under extreme test conditions) (20dB signal-to-noise ratio). 5.1.3 Test method
a. The block diagram of the test circuit and the instruments used are shown in Figure 14; RF signal
According to the generator
Modulator
Constant sound weighting
Receiver usable sensitivity test block diagram
b. The RF signal generator is working, the frequency is the nominal frequency of the receiver's specified channel, the modulation signal frequency is 1kHz, and the frequency deviation is 5.7kHz. Output level -50dBm,
c. Adjust the volume control of the receiver so that the receiver audio output power is 50% of the rated power (open the expander); d. Adjust the input signal level of the receiver so that the receiver output end obtains a 20dB signal-to-noise ratio, and record the RF input signal level at this time, which is the usable sensitivity of the receiver. 5.2 Adjacent channel selectivity
5.2.1 Definition
Adjacent channel selectivity refers to the ability of a receiver to receive a modulated useful signal when there is a modulated useless signal on the adjacent channel. It is expressed by the relative level of the modulated useless signal and the available sensitivity. 5.2.2 Index
Level 1 and 2 mobile stations: >60dB (±25kHz); Level 3 and 4 mobile stations: >55dB (±25kHz). 5.2.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 15. a.
RF patient number
(useful signal)
[useless number]
GB/T15942—1995
Sound adding technology
Signal ratio table
(loss and abandonment)
Sound self-leveling, table
Figure 15 Block diagram of adjacent channel selectivity test
RF signal generator B does not work:
RF signal generator A works, the RF signal frequency is the nominal frequency of the receiver's specified channel, the modulation signal frequency is c.
1kHz, the peak frequency deviation is ±5.7kHz, the signal generator output level is -50dBm, d. Adjust the output level of A to make the receiver output signal-to-noise ratio 20dB, and record the output level of A at this time UAe. Turn on the RF signal generator B, and adjust its carrier frequency to the adjacent channel of the receiver nominal frequency, that is, fB=f±25kHz, the modulation signal frequency is 400Hz, and the peak frequency deviation is ±5.7kHz; f. Adjust the output signal level of B until the receiver output signal-to-noise ratio is 14dB, and record the output level of B at this time UB; g. The adjacent channel selectivity of the receiver is:
UB—UA(dB)
5.3 Spurious response suppression
5.3.1 Definition
The spurious response suppression of a receiver refers to the measure of the receiver's ability to suppress any useless but responsive other frequency signals.
5.3.2 Indicators
When the deviation from the nominal frequency of the receiver exceeds 37.5kHz: Level 1 and Level 2 mobile stations: >65dB;
Level 3 and Level 4 mobile stations: >55dB.
5.3.3 Test method
The block diagram of the test circuit and the instruments used are shown in Figure 15a.
b. RF signal generator B is not working,
RF signal generator A is working, the RF signal frequency is the nominal frequency of the receiver's specified channel, the modulation signal frequency is 1kHz, the peak frequency deviation is ±5.7kHz, and the output signal level is -50dBm; then adjust the output level of A so that the audio output end of the receiver under test obtains a 20dB signal-to-noise ratio, and record U^d.
Turn on B, its modulation frequency is 400Hz, the peak frequency deviation is ±5.7kHz, and the output RF The signal level Uz is -33dBm, and then the RF signal frequency is adjusted to change within the range of 100kHz to 2000MHz. f. At any response frequency, adjust the output signal level of B to make the signal-to-noise ratio of the audio output end of the receiver under test drop to 14dB, and record the output level of B at this time UB
g The spurious response suppression of the receiver under test is: UB-UA (dB) 5.4 Intermodulation response suppression
5.4.1 Definition
Intermodulation response suppression refers to the measure of the receiver's ability to suppress in-band interference signals generated by the combination of two or more useless frequency signals.
5.4.2 Indicators
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