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GB/T 26685-2017: Methods of measurement for digital terrestrial television receiver
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Methods of measurement for digital terrestrial television receiver
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Basic data | Standard ID | GB/T 26685-2017 (GB/T26685-2017) | | Description (Translated English) | Methods of measurement for digital terrestrial television receiver | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | M74 | | Classification of International Standard | 33.160.25 | | Word Count Estimation | 54,569 | | Date of Issue | 2017-09-07 | | Date of Implementation | 2018-04-01 | | Older Standard (superseded by this standard) | GB/T 26685-2011 | | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China | GB/T 26685-2017: Methods of measurement for digital terrestrial television receiver---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Methods of measurement for digital terrestrial television receiver
ICS 33.160.25
M74
National Standards of People's Republic of China
Replace GB/T 26685-2011
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 I
1 Scope 1
2 Normative references 1
3 Terms, definitions, symbols and 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 3
4.3 Measurement mode of operation 3
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 Decoding Requirements 5
5.3 Demultiplexing requirements 19
5.4 Transport Stream Decoding Requirements 21
5.5 Video Feature Requirements 22
5.6 Audio Feature Requirements 24
5.7 Power Adaptability Requirements 26
5.8 Power consumption of the whole machine 26
5.9 Standby power consumption 27
5.10 Functional Requirements 27
Appendix A (Normative) Multipath Channel Model 38
Appendix B (Normative) Acceptable Errors 45
Appendix C (informative) Other multipath channel models 46
Reference 51
Foreword
This standard was drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 26685-2011 "Measurement Method for Terrestrial Digital Television Receiver", this standard is in line with GB/T 26685-2011
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), “Other multipath channels” (see 5.2.21) “Suppression
Protection of out-of-space 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, Shenzhen Digital TV National Engineering Laboratory Co., Ltd.,
National Digital Audio Video and Multimedia Product Quality Supervision and Inspection Center, TCL Group Co., Ltd., Sichuan Changhong Electric Co., Ltd.
Division, Qingdao Hisense Electric Co., Ltd., Qingdao Haier Electronics 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
Word 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., En
Zhipu Semiconductor (Shanghai) Co., Ltd., Ruidikechuang Microelectronics (Beijing) Co., Ltd., Mailing (Shanghai) Microelectronics Co., Ltd., Guangzhou Vision
Electronic Technology Co., Ltd., Jiangsu Yinhe Electronics Co., Ltd., National Radio and Television Product Quality Supervision and Inspection Center, Industry and Letter
The Fifth Institute of Electronics of the Ministry of Information, Shanghai Digital TV National Engineering Research Center Co., Ltd., Beijing Digital TV Engineering Laboratory Co., Ltd.
Division, Beijing Taihe Zhiyuan Technology Co., Ltd., Shenzhen Haisi Semiconductor Co., Ltd., Jiangsu Province, electronic information product quality supervision and inspection research
Institute, Morningstar Software R&D (Shenzhen) Co., Ltd., Lejin Electronic Research and Development Center Co., Ltd., Tianjin Samsung Electronics Co., Ltd., Nanjing Sharp
Electronics Co., Ltd., Shandong Matsushita Electronic Information Co., Ltd., Shanghai Suoguang Imaging Co., Ltd., Lianfa Technology (Hefei) Co., Ltd., Samsung
Letter Technology Research Co., Ltd., Rohde & Schwarz (China) Technology Co., Ltd.
The main drafters of this standard. Hu Peng, Chen Renwei, Chang Lin, Han Qiufeng, Wang Pingsong, Wang Wei, Li Yining, Zhang Linjuan, 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 26685-2011.
Ground digital television receiver measurement method
1 Scope
This standard specifies terrestrial digital television receivers that support the terrestrial digital television reception function of GB 20600-2006 (hereinafter referred to as
Performance measurement items, measurement conditions, and measurement methods.
This standard applies to standard definition and high definition terrestrial digital TV supporting GB 20600-2006 terrestrial digital TV receiving function.
Depending on 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 3174 PAL-D TV broadcasting technical specification
GB/T 20090.16 Advanced audio and video coding for information technology - Part 16. Radio and video
GB 20600-2006 Digital TV terrestrial broadcasting transmission system frame structure, channel coding and modulation
GB/T 22726 multi-channel digital audio codec technical specification
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 26686-2017 General specification for terrestrial digital television receivers
SJ/T 11157.2 Measurement methods for television broadcast receivers - Part 2. Methods for measuring electrical and acoustic performance of audio channels
SJ/T 11324-2006 Digital TV receiving equipment terminology
3 terms, definitions, symbols and 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
The following symbols apply to this document.
tD, MAX. The 0 dB maximum echo delay that the receiver specified in GB/T 26686-2017 should be able to withstand.
3.3 Abbreviations
The following abbreviations apply to this document.
AEF---acceptable error (AcceptableErrorFree);
EIT---Event Information Table (EventInformationTable);
EITp/f---current/follow-up event table (EITpresent/folowing);
EPG---Electronic Program Guide (Electronic Program Guide);
MPEG---MovingPictuteExpertsGroup;
NIT---Network InformationTable;
PCR---Program Clock Reference (ProgramClockReference);
PID---Packet Identifier;
PMT---Program Map Table (ProgramMapTable);
PSI---Program Specific Information (ProgramSpecificInformation);
SDT---Service DescriptionTable (ServiceDescriptionTable);
SI---Service Information (ServiceInformation);
TDT---Time and DateTable (TimeandDateTable);
TOT---Time Offset Table (TimeOffsetTable);
UHF---UltraHigh Frequency (UltraHighFrequence);
UTC---Universe TimeCo-ordinated;
VHF---Very High Frequency (VeryHighFrequence).
4 basic requirements for measurement
4.1 General instructions
4.1.1 Working conditions
Unless otherwise specified, the test receiver shall be tested at 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.
Measurement of performance parameters such as light and color should be performed in a dark room with a stray illuminance less than or equal to 1 lx.
The measurement of acoustic performance should be carried out in the anechoic chamber, which complies with the relevant provisions of SJ/T 11157.2.
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 performance of the receiver does not change significantly with time after the start of the measurement, the receiver should work stably 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
insert
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, unwanted transmit power in adjacent channel 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 power meter measurement accuracy. 0.1W
6 code stream generator output test required code stream
Table 2 (continued)
Serial number device name requirement
7 Gaussian noise generator noise bandwidth. ≥ 20MHz; RF output power (8MHz bandwidth). ≥ -50dBm
8-channel simulator analog channel. ≥20 path, Doppler type, delay, amplitude, Doppler shift, phase independent adjustment of each channel
9 The multiplexer digitally multiplexes the input stream signals into a multi-program stream.
10 SI generator edits and generates business information
11 Mixer frequency range. 30MHz~1GHz
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 in intra-channel (8MHz) peak power
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, the resolution is 720×576, and the chrominance parameter 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 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 receiver under test is a standard RF input signal.
Power
b) Set the digital TV test transmitter frequency to the measured 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 displayed 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 mode 1 of the tested receiver is verified, turn off the RF output of the digital TV test transmitter;
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 steps e) to f) 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 test receiver 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 Automatically switch 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 and 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 RF input signal 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 be consistent with 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 measurements.
5.2.4 Frequency capture range
5.2.4.1 Feature Description
Check the receiver's ability to adapt to carrier frequency deviations 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 RF input signal power;
b) adjust the receiver under test to make the screen display normal image, record the digital TV test transmitter carrier frequency 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 frequency range of the receiver under test to be Δf2~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 RF input signal 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 RF 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 RF input signal power;
b) adjust the receiver under test to make the screen display a normal image;
c) Turn on the Gaussian noise generator to increase the noise power so that the receiver under test does not work properly;
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 carrier power to 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 RF input signal power;
b) adjust the receiver under test to make the screen 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 Test 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 RF input signal power;
b) adjust the receiver to make the screen display a normal image;
c) Gradually reduce the output power of the digital TV test transmitter until the...
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