5.17
MER by carrier (COFDM)
5.17.1 Graph of MER by carrier (COFDM)
This function analyses the MER for each of the carriers forming the selected
channel and displays it continuously in a graphic form.
It is a very useful measurement in order to analyze systems in which signals of
different types and sources interfere among them, as in the case of the transition from
analogue to digital TV.
In next figure a MER by carrier analysis for a COFDM 8k signal is performed.
As it shows in the following figure, when analysing MER by carrier in this digital
channel appears three degradation areas throughout the channel that make suspect the
presence of an underneath analogue channel.
Analog level
Video Carrier
MER by carrier
Figure 50.- Scheme of interference due to TV analogue signal over a digital channel.
Page 72
Figure 49.- MER by carrier function.
Frequency
Colour
Audio
Subcarrier
Subcarrier
Carrier
USER'S MANUAL. TV EXPLORER HD / HD
MER
by carrier
LE
Carrier
05/2011