Annex 1 Signals Description - Promax HD RANGER 2 User Manual

ANNEX 1 SIGNALS DESCRIPTION
A1.1
DIGITAL signals
Digital TERRESTRIAL Television FIRST Generation
A1.1.1
(DVB-T standard/COFDM modulation)
DVB-T Parameters
Channel Bandwidth
►
This parameter affects the frequency separation of the carriers. Its value
is 6 MHz, 7 MHz or 8 MHz.
Spectral inversion
►
It detects if the input signal has been inverted.
FFT Mode
►
It defines the number of modulation carriers between values 2k, 4k and
8k.
Guard Interval
►
This parameter is the dead time between symbols; its purpose is to detect
problems due to multipath echoes. This parameter is expressed in terms
of the symbol duration: 1/4, 1/8, 1/16, 1/32.
Constellation
►
Modulation used by the carriers. It also defines the noise immunity of the
system (QPSK, 16-QAM and 64-QAM).
Code rate
►
Also known as Viterbi ratio. It defines the ratio between the number of
data bits and the total number of bits transmitted (the difference
corresponds to the number of control bits for the detection and recovery
of errors).
TS Hierarchy
►
The DVB-T standard gives the possibility of TDT transmissions with
hierarchical levels, that is, the simultaneous transmission of the same
program with different image qualities and levels of protection to different
noises, so the receiver can switch to a signal of lesser quality when
reception conditions are not optimal.
June 2014
3 3
1