MCMC MTSFB TC T011:2014

MCMC MTSFB TC T011:2014

5.6.7 Immunity to Co-Channel Interference from Analogue TV Signals

Section 7.0

Test Case

Requirement

Immunity to Co-Channel Interference from Analogue TV Signals.

The receiver shall perform better than the RF figure specified in Annex A of the

SKMM MTSFB TC T004:2013 - Specification for Digital Terrestrial Television

Broadcast Service Receiver when the signal is exposed to interference from a co-channel G/PAL signal including video with teletext, FM audio and a NICAM sub carrier while maintaining QEF reception.

Purpose

Expectation

To verify the QEF reception for DVB-T2 receiver when there is a co-channel interference from analogue TV.

The received signal shall have a 30s error free video for DVB-T2 modes with C/I equal or better than the requirement.

Test Instrument

Set Up

Figure C

Calibration

Requirement

Test Outline

1 Set up the equipment based on the modes outlined in Annex A of the

SKMM MTSFB TC T004:2013 - Specification for Digital Terrestrial

Television Broadcast Service Receiver. (Start with MS 1)

2 Ensure the following:

1. 10% modulation depth for vision carrier.

2. NICAM signal level is at -20dB and +5.85MHz relative to the vision carrier.

3. Insert 12 lines of teletext.

3 Set the analogue TV source with the following requirements:

1. The analogue TV source and DVB-T2 modulator shall be connected to the same reference signal (10MHz).

2. The analogue TV source shall have 0Hz centre frequency offset from the digital TV source.

3. The analogue TV source should not have too high out-of-band emissions to avoid interference to other frequencies.

4. Use a colour bar 75% as the input for PAL signal.

5. FM sound carrier can be modulated at a deviation of 1kHz - 50kHz tone, and the level set at -13dB relative to the vision carrier.

4 Calibrate the C/I level (Att C and Att I).

5 Ensure that the receiver signal input level (wanted signal) is set to -50dBm.

1 Execute the test for the range of the frequencies and modes outlined in the

Result Table.

2 Increase the C/I from low value to higher value until the QEF measurement is achieved.

3 Remark

The performance requirement is based on 30 seconds error free video.

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MCMC MTSFB TC T011:2014

Result

Centre Frequency (MHz)

MS 1

MS 2

MS 3

MS 4

C/I

666

X

** Remark - If 'Failed', please indicate the level of failure (dB)

Passed Failed Not Tested Conformity

Remark

1

2

3

Note: Attach graph (if any)

X Indicates no test needed

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