Promax TV Explorer HD Manual De Usuario página 159

USER'S MANUAL. TV EXPLORER HD / HD
3) Carriers (Number of carriers)
It defines the number of modulation carriers between 2k, 4k and 8k. To modify its
value, place the marker over the Carriers field by turning the rotary selector and
then press it: a menu will appear on the screen. Turning the rotary selector
select the desired value for the Carriers parameter and finally press it again to
validate.
4) Spectral Inv. (spectral inversion)
This option enables spectral inversion to be applied to the input signal, though in
the majority of cases it should be in the OFF position (not inversion).
This configuration menu shows, besides the user definable COFDM signal
parameters, the value of the rest of signal parameters detected automatically:
Code Rate Also known as Viterbi ratio, defines the ratio between the data bits
number and the total number of bits transmitted (the difference
corresponds to the number of control bits for the error detection and
recovery).
Modulations Carriers modulation. It also defines the system noise immunity.
(QPSK, 16-QAM and 64-QAM).
Hierarchy The DVB-T/H norm contemplates the possibility to make a TDT
transmission with hierarchical levels, it is to say a simultaneous
transmission of the same program with different image qualities and
noise protection levels, in order the receiver can exchange to a
signal of smaller quality when the reception conditions are not
optimal.
Cell ID Cell identifier. Shows the transmissor identification code.
Figure 20.- Screen of mesurement configuration (COFDM signals).
05/2011
LE
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