SEFRAM 7849B User Manual page 110

BB B Error vector
RRR Magnitude vector (from the reference dot to the ideal dot)
M
ODULATION: Once the signal has been coded, it is modulated with a carrier wave for transmission.
AM (Amplitude Modulation): analogical modulation of the amplitude of the carrier wave
FM (Frequency Modulation): analogical modulation of the frequency of the carrier wave
QPSK (Quadrature Phase Shift Keying): phase digital modulation
QAM (Quadrature Amplitude Modulation): phase and amplitude digital modulation
COFDM (Coded Orthogonal Frequency Division Multiplex): phase and amplitude digital modulation on
multiple carrier waves; for DTT.
M
PEG : Motion Picture Expert Group
MPEG is a family of compressed digital coding formats for audio / video. The aim of MPEG coding is to
hugely reduce the amount of transmitted information with as little loss as possible thanks to very complex
compression algorithms.
The MPEG 2 option on the SEFRAM field meters allows you to view and control TV programs (coded
under MPEG) directly on the meters.
ex.: On the Astra satellite, the EURONEWS and SPORT + channels are non-crypted and visible on the
field meters.
M
: Set of channels broadcasted by the same operator (smaller set than a package). In DTT, a
ULTIPLEX
multiplex has a 24.5Mbits/s flow rate. A multiplex enables the diffusion of 6 programs in standard
definition
N
: Network Information Table – Information about the network/package
IT
Enables the display of a description of the measured transponder. The information is sent non-coded in
the data flow from the QAM, COFDM or QPSK decoder. The information items are:
- Name of the operator
- List of the transponders of the package
- Orbital position of the satellite (in Satellite mode).
O
: The central frequency of a DTT channel may be shifted by ± 166.7 kHz in case of adjacent
FFSET
analogical channel to prevent disturbances
O
L: A local oscillator that converts the frequency received from the satellite, in GHz, into an intermediary
frequency that the demodulator can use, in MHz.
ex.: a 11.778 GHz frequency from the satellite passing through a 10.6 GHz OL LNB becomes a
11.778-10.600=1.178 MHz
See LNB scheme.
P
AUDIO AND VIDEO ID: Packet Identifier. MPEG service information.
In the digital MPEG flow, the (audio or video) packets all include a PID to get binary data from each ser-
vice.
F
requency plan: There are various Frequency Plans according to places and standards. In the
SEFRAM
field meters, the frequency plans are pre-programmed: they gather the most frequently used frequency
bands.
M
easure plan : Allows the simultaneous view of characteristics (frequency, channel, standard...) of var-
ious programs (TF1, France2...) with location of measures except tolerance. Allows to carry out BER live
measures, for a list of programs.
7849B – 7859B – 7817B
p.
110