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GB/T 26684-2017 (GB/T26684-2017)

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GB/T 26684-2017: PDF in English (GBT 26684-2017)
GB/T 26684-2017
Methods of measurement for digital terrestrial set-top box
ICS 33.160.25
M74
National Standards of People's Republic of China
Replace GB/T 26684-2011
Ground digital television receiver measurement method
Published on.2017-09-07
2018-04-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
China National Standardization Administration issued
Content
Foreword III
1 range 1
2 Normative references 1
3 Terms and definitions, symbols, abbreviations 1
3.1 Terms and Definitions 1
3.2 Symbol 1
3.3 Abbreviations 1
4 Measurement basic requirements 2
4.1 General Description 2
4.2 Test Signal 2
4.3 Measurement mode 2
4.4 Measurement systems and test instruments 3
4.5 Standard measurement conditions 4
5 Measurement items and methods 5
5.1 System Block Diagram 5
5.2 RF Demodulation and Channel Channel Decoding Requirements 5
5.3 Transport Stream Decoding Feature Requirements 19
5.4 Baseband video output performance requirements 21
5.5 Audio Output Features 34
5.6 Functional requirements 35
5.7 Power Adaptability Requirements 35
5.8 Power consumption 36
5.9 Standby power consumption 36
Appendix A (Normative) Multipath Channel Model 37
Appendix B (Normative) Acceptable Errors 44
Appendix C (informative) Other multipath channel models 45
Foreword
This standard was drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 26684-2011 "Measurement method for terrestrial digital TV receiver", this standard and GB/T 26684-2011
In addition to the editorial changes, the main technical changes are as follows.
--- Terms, definitions, symbols and abbreviations add "symbols" (see 3.2);
---Measure the basic requirements to increase the "measurement mode of operation" (see 4.3);
--- RF demodulation and channel decoding requirements increase "working mode and modulation parameter changes" (see 5.2.2), "suppress two-path long echo capability"
(see 5.2.16), “Suppression of three-path long echo capability” (see 5.2.17), “Suppressing channel perturbation capability 1 under fixed reception conditions” (see
5.2.18), “Suppress channel perturbation capability 2 under fixed reception conditions” (see 5.2.19), “Suppress other multipath channel performance” (see
5.2.21) “Suppression of guard-out-of-band echo capability” (see 5.2.22) and “RF loop output gain” (see 5.2.23);
--- Added Appendix C (informative) other multipath channel models (see Appendix C).
Please note that some of the contents of this document may involve patents. The issuing organization of this document is not responsible for identifying these patents.
This standard was proposed by the Ministry of Industry and Information Technology of the People's Republic of China.
This standard is under the jurisdiction of the National Technical Committee for Standardization of Audio, Video and Multimedia Systems and Equipment (SAC/TC242).
This standard is mainly drafted by. China Electronics Technology Standardization Research Institute, National Digital Audio Video and Multimedia Product Quality Supervision and Inspection
Xin, Shenzhen Digital TV National Engineering Laboratory Co., Ltd., Sichuan Changhong Electric Co., Ltd., Qingdao Hisense Electric Co., Ltd.
Company, Qingdao Haier Electronics Co., Ltd., TCL Group Co., Ltd., Shenzhen Skyworth-RGB Electronics Co., Ltd., BOE Technology
Group Co., Ltd., Nanjing Panda Electronics Co., Ltd., Tsinghua University, Gaotuo Xunda (Beijing) Technology Co., Ltd., Shanghai HD Digital
Technology Industry Co., Ltd., Beijing Haier IC Design Co., Ltd., Beijing Zhongtian Lianke Technology Co., Ltd., Hangzhou Guoxin Technology Co., Ltd.
Co., Ltd., Shenzhen Lihe Microelectronics Co., Ltd., Guangzhou Guangsheng Digital Technology Co., Ltd., Shenzhen Core Technology Co., Ltd., Enzhi
Pu Semiconductor (Shanghai) Co., Ltd., Ruidi Kechuang Microelectronics (Beijing) Co., Ltd., Mai Ling (Shanghai) Microelectronics Co., Ltd., Guangzhou Vision Source
Sub-Technology Co., Ltd., Jiangsu Yinhe Electronics Co., Ltd., National Radio and Television Product Quality Supervision and Inspection Center, Industry and Information
The Fifth Institute of Electronics, Shanghai Digital TV National Engineering Research Center Co., Ltd., Beijing Digital TV Engineering Laboratory Co., Ltd.
Beijing Taihe Zhiyuan Technology Co., Ltd., Shenzhen Haisi Semiconductor Co., Ltd., Jiangsu Electronic Information Product Quality Supervision and Inspection Institute,
Morningstar Software R&D (Shenzhen) Co., Ltd., Lejin Electronic Research and Development Center Co., Ltd., Tianjin Samsung Electronics Co., Ltd., Nanjing Sharp Electric
Subsidiary Co., Ltd., Shandong Matsushita Electronic Information Co., Ltd., Shanghai Suoguang Imaging Co., Ltd., Lianfa Technology (Hefei) Co., Ltd., Samsung Communications
Technology Research Ltd., Rohde & Schwarz (China) Technology Co., Ltd.
The main drafters of this standard. Hu Peng, Chen Renwei, Chang Lin, Wang Pingsong, Wang Wei, Li Yining, Zhang Linjuan, Han Qiufeng, Wu Wei, Li Wei, Sun Runyu,
Pan Changyong, Jia Wei, Liang Weiqiang, Qiang Hui, Yang Guang, Feng Xianghui, Chen Liheng, Xu Wei, Niu Xiaoru, Guo Xiancheng, Han Wenquan, Wang Hongxin, Zhang Jingping,
Zhong Zhiyang, Lu Guobing, Jia Kai, Cheng Yang, Zhu Xianliang, Yin Huiqing, Fang Haidong, Shi Yi, Wan Minyong, Han Wenfang, Lin Weifeng, Cao Yu, Yang Xing, Lu Gang,
Su Yukun, Liu Yi, Liu Ansheng, Hu Haining, Zhang Wei.
The previous versions of the standards replaced by this standard are.
---GB/T 26684-2011.
Ground digital television receiver measurement method
1 Scope
This standard specifies a terrestrial digital TV receiver that supports GB 20600-2006 terrestrial digital TV reception function (hereinafter referred to as
Measurement conditions, electrical performance measurement items, and measurement methods.
This standard applies to standard definition and high definition terrestrial digital TV supporting GB 20600-2006 terrestrial digital TV receiving function.
View the receiver.
2 Normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.
Pieces. For undated references, the latest edition (including all amendments) applies to this document.
GB 3174PAL-D system television broadcasting technical specification
GB 20600-2006 Digital TV terrestrial broadcasting transmission system frame structure, channel coding and modulation
GB/T 22122-2008 Digital TV surround sound sound measurement method
GB/T 26270-2010 Digital TV receiving equipment standard test signal
GB/T 26681-2011 Technical requirements and measurement methods for terrestrial digital television standard test transmitters
GB/T 26683-2017 General specification for terrestrial digital TV receivers
GB/T 26685-2017 Ground digital television receiver measurement method
SJ/T 11324-2006 Digital TV receiving equipment terminology
3 Terms and definitions, symbols, abbreviations
3.1 Terms and definitions
The following terms and definitions as defined by SJ/T 11324-2006 apply to this document.
3.1.1
Acceptable error acceptablefreefree
The error event that was not corrected within the specified time during signal reception is less than a certain threshold.
3.2 symbol
tD, MAX. The 0 dB maximum echo delay that the receiver specified in GB/T 26683-2017 should be able to withstand.
3.3 Abbreviations
The following abbreviations apply to this document.
AEF. Acceptable Error (AcceptableErrorFree)
EPG. Electronic Program Guide (ElectronicProgramGuide)
PSI. Program Specific Information (ProgramSpecificInformation)
SI. Business Information (ServiceInformation)
UHF. UltraHigh Frequency (UltraHighFrequence)
VHF. Very High Frequency (VeryHighFrequence)
4 basic requirements for measurement
4.1 General instructions
4.1.1 Working conditions
Unless otherwise specified, the receiver shall be tested in accordance with the standard measurement conditions specified in 4.5.
4.1.2 Measurement site
The measurement shall be carried out in a room that is free from interference from external RF and low-frequency electromagnetic fields. If external electromagnetic interference affects the measurement result, the measurement is performed.
The amount should be carried out in the shielded room.
4.1.3 Measuring environmental conditions
4.1.3.1 Measurement conditions
The measurement conditions should meet the following requirements.
Ambient temperature. 15 ° C ~ 35 ° C;
Relative humidity. 25%~75%;
Atmospheric pressure. 86kPa~106kPa;
Power supply. [220 × (1 ± 5%)] V, [50 × (1 ± 2%)] Hz.
4.1.3.2 Arbitration conditions
The arbitration conditions shall meet the following requirements.
Ambient temperature. 20 ° C ± 2 ° C;
Relative humidity. 60%~70%;
Atmospheric pressure. 86kPa~106kPa;
Power supply. [220 × (1 ± 2%)] V, [50 × (1 ± 1%)] Hz;
Power supply harmonics. 0~5%.
4.1.4 Stabilization time
In order to ensure that the receiver performance does not change significantly over time after the start of the measurement, the receiver should be stable under standard measurement conditions.
15min.
4.2 Test signal
See GB/T 26270-2010.
4.3 Measurement mode
The measurement mode of operation is shown in Table 1, where operating mode 11 is only applicable to "operating mode and modulation parameter changes".
Table 1
Working mode carrier number
Forward error correction
Code rate
Symbol constellation
Mapping
Frame header mode
Frame head phase
Variety
Symbol interleaving
Option
Double pilot insertion
Net rate
Mbps
1 C=3780 0.4 16QAM PN945 Change 720 - 9.626
2 C=1 0.8 4QAM PN595 - 720 Do not insert 10.396
3 C=3780 0.6 16QAM PN945 Change 720 - 14.438
4 C=1 0.8 16QAM PN595 - 720 does not insert 20.791
5 C=3780 0.8 16QAM PN420 Change 720 - 21.658
6 C=3780 0.6 64QAM PN420 Change 720 - 24.365
7 C=1 0.8 32QAM PN595 - 720 does not insert 25.989
8 C=3780 0.8 16QAM PN945 Change 720 - 19.251
9 C=3780 0.6 64QAM PN945 Change 720 - 21.658
10 C=3780 0.8 64QAM PN420 Change 720 - 32.486
11 C=1 0.8 4QAM-NR PN945 No change 240 Insert 4.813
4.4 Measurement systems and test instruments
See Table 2 for specific requirements.
Table 2
Serial number device name requirement
1 Digital TV test transmitter meets the relevant requirements of GB/T 26681-2011, MER≥36dB
2 analog TV test transmitter
Carrier frequency range. 40MHz~1GHz, amplitude. ≥-10dBm, useless transmit power in adjacent channels is less than
Carrier power. ≥50dB
3 Spectrum analyzer frequency range. 40MHz~1GHz, average noise level. ≤150dBc/Hz
4 Network analyzer frequency range. 40MHz~1GHz, reflection loss measurement accuracy. ≤0.1dB, impedance. 75Ω
5 Video analyzer measures baseband video signal level, frequency, delay, phase difference, etc. Bandwidth. ≥6MHz
6 High-definition video analyzer analyzes and measures the baseband video signal level, frequency, delay, phase difference, etc. Bandwidth. ≥30MHz
7 audio analyzer
Realize audio measurement amplifier, distortion meter and other functions, and have 1kHz, 1/3oct bandpass filter, conform to O type
Tolerance A weighting filter
8 power power meter measurement accuracy 0.1W
9 code stream generator output test required code stream
10 Gaussian noise generator noise bandwidth. ≥ 20MHz; RF output power (8MHz bandwidth). ≥ -50dBm
11 channel simulator analog channel. ≥ 20 diameter, Doppler type, delay, amplitude, Doppler shift, phase independent adjustable of each channel
12 The multiplexer digitally multiplexes the input stream signals into a multi-program stream.
13 SI generator edits and generates business information
14 Mixer frequency range. 30MHz~1GHz
15 color monitor meets receiver display requirements
16 oscilloscope bandwidth. ≥30MHz
4.5 Standard measurement conditions
4.5.1 Measurement channel
The minimum received signal power should measure the operating mode 7 performance on all VHF and UHF channels, with the worst results for the project.
The measurement result of mode 7.
Reflection loss, suppression of analog TV adjacent-frequency interference capability, suppression of digital TV adjacent-channel interference capability in 14 channels (482MHz), 31-frequency
The channel (658 MHz) and channel 47 (786 MHz) were measured.
Other items were measured on channel 31 (658 MHz).
4.5.2 Standard RF input signal power
The RF signal input to the receiver is represented by the average power in the channel (8 MHz).
The standard useful input signal power for RF TV signals should be -60 dBm at the RF input.
4.5.3 Analog TV signal
The analog TV signal for interference uses PAL-D RF signal, and the modulated video signal is 100/0/75/0 color bar signal, audio signal
For 1 kHz signals, other requirements shall be in accordance with GB 3174. Analog TV signal power with peak power in the channel (8MHz)
Said.
4.5.4 Gaussian noise
Gaussian noise should cover the interfered channel. Gaussian noise power is expressed as the average power in the interfered channel (8 MHz).
4.5.5 Impulse noise
The principle of impulse noise generation is shown in Figure 1.
figure 1
The impulse noise power is expressed as the average power of the Gaussian noise generated by the Gaussian noise generator in the interfered channel (8 MHz).
4.5.6 Multipath channel
See Appendix A for the multipath channel model.
4.5.7 Standard code stream
The test stream program should be no less than 1 minute in length and contain at least one video program and one audio program. Video program should be
Active image sequence.
When testing and evaluating the system payload data rate is greater than 14 Mbps, the video program included in the test stream should be at least
Contains a set of high-definition programs with a basic stream data rate greater than 8 Mbps, a frame rate of 25 Hz, an aspect ratio of 16.9, and a resolution of 1920×1080.
The chromaticity parameter is 4.2.0.
If the standard stream program is included in the test stream, the frame rate is 25 Hz, the aspect ratio is 4.3, and the resolution is 720×576. The chrominance parameter
It is 4.2.0.
5 Measurement items and methods
5.1 System Block Diagram
The system block diagram is shown in Figure 2.
figure 2
5.2 RF Demodulation and Channel Channel Decoding Requirements
5.2.1 Overview
This clause accepts the decision threshold with acceptable error. See Appendix B for provisions on acceptable errors.
5.2.2 Working mode and modulation parameter change
5.2.2.1 Feature Description
Check if the receiver supports all the operating modes specified in GB 20600-2006, and the receiver automatically changes when the modulation parameters change.
Switch time. The automatic switching time unit is seconds (s).
5.2.2.2 Test block diagram
The test block diagram is shown in Figure 3.
image 3
5.2.2.3 Measurement method
The measurement steps are as follows.
a) Connect the test system according to Figure 3, the code stream generator outputs a standard moving image sequence (standard code stream data rate is less than or equal to
4.813Mbps), adjust the output power of the digital TV test transmitter, so that the input power of the tested receiver is the standard input power;
b) Set the digital TV test transmitter frequency to the typical channel frequency, and set the digital TV test transmission according to the working mode 1 in Table 1.
Machine working mode parameters;
c) Adjust the receiving frequency of the receiver under test to match the frequency of the digital TV test transmitter, and observe whether the image on the screen is normal and
The reception status is recorded in Table 3;
d) Repeat steps b)~c) in working mode i (i=2~11) to verify the receiving condition of the receiver under test;
e) After the test receiver 1 is verified, the digital TV test transmitter RF output is turned off;
f) Digital TV test transmitter working mode 2 After setting the parameters, turn on the digital TV test transmitter RF output, using seconds
The table records the switching time T1-2 of the working mode 1 switching to the working mode 2;
g) Repeat step e) in working mode i (i=2~10) to measure switching times T2-3, T3-4, T4-5, T5-6, T6-7, T7-8,
T8-9, T9-10, T10-11;
h) After the tested receiver operating mode 11 is verified, the digital TV test transmitter RF output is turned off;
i) Digital TV test transmitter working mode 1 After setting the parameters, turn on the digital TV test transmitter RF output, using seconds
The table records the working mode 11 to switch to the switching mode T11-1 of the working mode 1;
j) Take the average values of T1-2, T2-3, T3-4, T4-5, T5-6, T6-7, T7-8, T8-9, T9-10, T10-11, and T11-1 as Automatic switching
time.
table 3
Serial number working mode receiving condition switching time
1 1 □ Support □ Not supported -
2 2 □ Support □ does not support T1-2
3 3 □ Support □ does not support T2-3
4 4 □ Support □ does not support T3-4
5 5 □ Support □ does not support T4-5
6 6 □ Support □ does not support T5-6
7 7 □ Support □ does not support T6-7
8 8 □ Support □ does not support T7-8
9 9 □ Support □ does not support T8-9
10 10 □ Support □ does not support T9-10
11 11 □ Support □ does not support T10-11
12 1 - T11-1
5.2.3 Frequency range
5.2.3.1 Feature Description
Check if the receiver can receive normally in the VHF, UHF frequency range.
5.2.3.2 Test block diagram
The test block diagram is shown in Figure 4.
Figure 4
5.2.3.3 Measurement method
The measurement steps are as follows.
a) Connect the test system according to Figure 4, the code stream generator outputs the standard moving image sequence, and sets the digital TV test transmitter as the working mode.
Equation 7, adjusting the output power of the digital TV test transmitter so that the input power of the receiver under test is the standard input power;
b) setting the digital TV test transmitter frequency to the measured channel center frequency;
c) Adjust the receiving frequency of the receiver under test to match the frequency of the digital TV test transmitter, and observe whether the image displayed on the screen is normal;
d) If the receiver receives normally, record the channel supported by the receiver under test, otherwise the record is not supported;
e) Repeat steps b)~d) on all UHF and VHF channels and record the test.
5.2.4 Frequency capture range
5.2.4.1 Feature Description
Check the receiver's ability to adapt to carrier frequency deviation in kilohertz (kHz).
5.2.4.2 Test block diagram
The test block diagram is shown in Figure 4.
5.2.4.3 Measurement method
The measurement steps are as follows.
a) Connect the test system according to Figure 4, the code stream generator outputs the standard moving image sequence, and adjusts the output power of the digital TV test transmitter.
Rate, so that the input power of the receiver under test is the standard input power;
b) adjusting the receiver under test to make the color monitor display a normal image, recording the carrier frequency of the digital TV test transmitter at this time is f;
c) Gradually reduce the carrier frequency of the digital TV test transmitter until the receiver under test is not working properly, and then gradually increase the digital TV
Test the transmitter carrier frequency until acceptable error reception, record the carrier frequency f1 at this time, calculate Δf1=f1-f;
d) Gradually increase the carrier frequency of the digital TV test transmitter until the receiver under test is not working properly, and then gradually reduce the digital TV
Test the transmitter carrier frequency until acceptable error reception, record the carrier frequency f2 at this time, calculate Δf2=f2-f;
e) Record the receiver receiver frequency capture range from Δf2 to Δf1.
5.2.5 Reflection loss
5.2.5.1 Feature Description
Check the impedance matching of the receiver RF input in decibels (dB).
5.2.5.2 Test block diagram
The test block diagram is shown in Figure 5.
Figure 5
5.2.5.3 Measurement method
The measurement steps are as follows.
a) Set the center frequency of the network analyzer to the center frequency of the channel under test, the level is 0dBm, the bandwidth is 8MHz, and the measurement item is reversed.
Shot loss test
b) Calibrate the network analyzer with a shunt, opener and 75Ω standard load, respectively;
c) Connect the test system according to Figure 4, the code stream generator outputs the standard moving image sequence, and sets the digital TV test transmitter frequency to be
Measuring the channel center frequency, adjusting the output power so that the input power of the receiver under test is the standard input power;
d) adjust the receiver under test to make the screen display a normal image;
e) Connect the test system according to Figure 5 and connect the network analyzer to the input of the receiver under test;
f) Record the result of the strongest reflection in the 8MHz bandwidth as the reflection loss of the channel of the receiver under test.
5.2.6 Gaussian carrier-to-noise ratio threshold
5.2.6.1 Feature Description
Check the minimum carrier-to-noise ratio of the receiver that can operate normally under Gaussian channel conditions in decibels (dB).
5.2.6.2 Test block diagram
The test block diagram is shown in Figure 6.
Image 6
5.2.6.3 Measurement method
The measurement steps are as follows.
a) Connect the test system according to Figure 6. The code stream generator outputs a standard moving image sequence to adjust the digital TV test transmitter output.
Rate, so that the input power of the receiver under test is the standard input power;
b) adjust the receiver under test to make the color monitor display a normal image;
c) Turn on the Gaussian noise generator to increase the noise power, so that the receiver under test cannot work normally;
d) gradually reduce the noise power until acceptable error reception;
e) Record the Gaussian carrier-to-noise ratio threshold of the receiver under test as the ratio of the carrier power to the noise power at this time.
5.2.7 Static multipath carrier-to-noise ratio threshold
5.2.7.1 Feature Description
Check the minimum carrier-to-noise ratio of the receiver that can operate normally under static multipath channel conditions in decibels (dB).
5.2.7.2 Test block diagram
The test block diagram is shown in Figure 7.
Figure 7
5.2.7.3 Measurement method
The measurement steps are as follows.
a) Connect the test system according to Figure 7, the code stream generator outputs a standard moving image sequence, and adjusts the output power of the digital TV test transmitter.
Rate, so that the input power of the receiver under test is the standard input power;
b) adjust the receiver under test to make the color monitor display a normal image;
c) Set the channel simulator according to the multipath channel model in Appendix A. When measuring the carrier-to-noise ratio threshold of the Rice channel, press A.2 to measure
Set the channel carrier-to-noise ratio threshold according to A.1;
d) Turn on the Gaussian noise generator to increase the noise power, so that the receiver under test cannot work normally;
e) gradually reduce the noise power until acceptable error reception;
f) Record the static multipath carrier-to-noise ratio threshold of the receiver under test as the ratio of carrier power to noise power at this time.
5.2.8 Receive signal power range
5.2.8.1 Feature Description
Check the received signal power range of the receiver for normal operation in decibels milliwatts (dBm).
5.2.8.2 Measurement block diagram
The test block diagram is shown in Figure 8.
Figure 8
5.2.8.3 Measurement method
The measurement steps are as follows.
a) Connect the test system according to Figure 8. The code stream generator outputs a standard moving image sequence to adjust the output of the digital TV test transmitter.
Rate, so that the input power of the receiver under test is the standard input power;
b) adjust the receiver under test to make the color monitor display a normal image;
c) Gradually reduce the output power of the digital TV test transmitter until the receiver under test is not working properly, and then gradually increase the digital TV
Test transmitter output power until acceptable error reception;
d) recording the minimum received signal power of the tested receiver as the power of the receiver input at the time;
e) Gradually increase the output power of the digital TV test transmitter until the receiver under test is not working properly, and then gradually reduce the digital TV
Test transmitter output power until acceptable error reception;
f) Record the maximum received signal power of the receiver under test as the power of the receiver input at this time.
5.2.9 Suppress analog TV adjacent channel interference capabili......
......

BASIC DATA
Standard ID GB/T 26684-2017 (GB/T26684-2017)
Description (Translated English) Methods of measurement for digital terrestrial set-top box
Sector / Industry National Standard (Recommended)
Classification of Chinese Standard M74
Word Count Estimation 52,550
Date of Issue 2017-09-07
Date of Implementation 2018-04-01
Older Standard (superseded by this standard) GB/T 26684-2011
Administrative Organization National Standard Committee on Audio, Video and Multimedia Systems and Equipment (SAC/TC 242)