IEC 62028:2002 pdf download
IEC 62028:2002 pdf download.General methods of measurement for digital television receivers.
5.3 RF (radio frequency) television signal
5.3.1 General
The RF signal is usually digitally modulated by a MPEG transport stream containing audio,
video and service information data.
Subclauses 3.3 and 3.4 of IEC 60107-1 as far as relevant shall apply.
5.3.2 Reference modulation
The modulation shall be in accordance with the system for which the receiver under test is designed.
(1) Cable systems:
64QAM, 16VSB modulation formats are used on cable systems.
(2) Satellite broadcast:
QPSK, TC-8PSK, BPSK modulation formats are used for satellite broadcast.
(3) Terrestrial broadcast:
COFDM, band-segmented OFDM, 8VSB modulation formats are used for terrestrial broadcasting.
QPSK, DQPSK, 16QAM and 64QAM are used for modulating carriers when using OFDM (COFDM or band-segmented OFDM) modulation format for transmission.
In the following sections, the typical notation “QAM, PSK, OFDM and VSB” are used instead of 16QAM, 64QAM, 256QAM, QPSK, COFDM, band-segmented OFDM and 8VSB.
5.3.3 Signal level
The RF signal level shall be expressed by the r.m.s. voltage of the modulated carrier on a terminating resistor. The definition of the RF signal level is according to 3.4 of IEC 60107-1.
5.4 Measuring systems and test instruments
5.4.1 Measuring system
A notional block diagram for the measuring system is shown in figure 2.
5.4.2 Base band test signal generators
The video signal generator can be used for still picture image, and VCR and DVD can be used for moving picture image.
5.4.3 Service data generator
Under consideration.
5.4.4 Encoders
The video encoder shall be capable of encoding video signals in accordance with MPEG2 format.
The audio encoder shall be capable of encoding audio signals in accordance with MPEG2 or AC-3 or MPEG2-AAC format.
5.4.5 Modulator
The modulator shall modulate the transport stream at the output of the multiplexer according
to the broadcasting system.
5.4.6 BER analyzer
Under consideration.
5.5 Standard measuring conditions
Unless otherwise specified, the standard conditions described in this subclause shall be applied.
5.5.1 Standard input signal levels
5.5.1.1 Standard RF input signal level for receivers for QAM systems
The standard level at the input terminal shall be 60 dB(pV) when terminated with a 75
resistor.
5.5.1.2 Standard RF input signal level for receivers for OFDM systems
The standard level at the input terminal shall be 60 dB(pV) when terminated with a 75 2 resistor.
5.5.1.3 Standard RF input signal level for receivers for VSB systems
The standard level at the input terminal shall be 60 dB(pV) when terminated with a 75 resistor.
5.5.1.4 Standard RF input signal level for receivers for QPSK systems
The standard level at the input terminal shall be 60 dB(pV) when terminated with a 75 2 resistor.
5.5.1.5 Standard input signal level for receivers for PSTN/ISDN systems Under consideration.
5.5.2 Standard output signal levels Under consideration.
5.5.3 Standard receiver settings Under consideration.
5.5.4 General conditions Under consideration.
5.6 Standard viewing conditions
The standard viewing condition to be applied shall be those of IEC 60107-1.
6 Assessment of received picture and sound quality
6.1 Subjective tests of basic received quality
6.1.1 Objectives
The basic received quality tests will be conducted to assess the subjective quality of image and sound sequences that were encoded, modulated, transmitted, demodulated and decoded by the test digital system. Multiple modes of operation of the digital system may be tested.
6.1.2 Methodology
6.1.2.1 Testers
Testers should be recruited locally and screened for audio-visual abilities (normal or corrected-to-normal), and language comprehension. Those who meet the screening criteria will be permitted to participate in the tests.
Separate groups of testers were used in the different basic received quality tests. At least 15 testers shall participate in any given session.
6.1.2.2 Test material
Each sequence should consist of the central 10 s of a 15 s video clip. These sequences should be selected by a panel of experts to ensure that a broad range of image and sound attributes are represented.
Reference sequences for the each format tests of the digital system will always be displayed in the source format. Test sequences will be generated by processing (encoding, modulating, transmitting, demodulating and decoding) source sequences through the digital system.
