Digital Signal Disturbed by Impulsive Noise

This paper presents and comments on test results and measurement procedures carried out mainly in the laboratory to investigate the degree of immunity of DTV reception in the presence of impulse noise. The objective of these tests was to compare the resilience to this type of noise provided by the DTV standards: ATSC, DVB-T and ISDB-T. The field test in the city of SÃo Paulo, Brazil, showed a high and unforeseen rate of places presenting considerable degradation caused by impulsive noise. Previous studies do not reflect the reality of the impulse noise found in the Brazilian environment. Under these circumstances, a need arises for simulating interference conditions caused by ignition motors, hairdryers, blenders, etc, in the laboratory. Our laboratory tests utilized an impulse noise generator that was constructed especially to emulate ignition noise, but which was shown to be equally satisfactory in emulating other kinds of impulse noise. This paper also describes the operating principles and specifications of the impulse noise generator.