Glossary - emitor Satlook Micro G2 Manuel D'utilisation

8PSK: (8 Phase Shift Keying). This is the modulation type that is used for DVB-S2 also 8PSK 8PSK 8PSK
called HD. In 8PSK, a symbol has 8 states or 3 bits. On the constellation diagram, an
8PSK signal either be "Normal", with the eight points around a circle centred on the
origins or "Rotated" 22.5 degrees.
Attenuator: The attenuator inserts an active resistance into the RF path and reduces the Attenuator:
Attenuator: Attenuator:
signal level about 3 dB.
BER BER: (Bit Error Ratio) This is the ratio of
BER BER
usually expressed in scientific notation as BER = 2 X 10
-6
than 1 X 10 for good reception.
dB: (decibel) The decibel is a logarithmic ratio of voltage (or power) to a standard or dB: dB: dB:
reference voltage (or power).
DiSEqC DiSEqC: see Appendix D DiSEqC DiSEqC
DVB- - - - S S S S or DVB DVB DVB DVB DVB DVB- - - - S2: DVB S2: S2: see Appendix E S2:
Ext Power: When the Satlook G2 / HD is connected to the power supply and plugged in, Ext Power:
Ext Power: Ext Power:
then this is displayed on the Analog screen.
FEC: FEC: (Forward Error Correction) This is the error control used in DVB and other systems
FEC: FEC:
to correct errors in transmission. To do this, the data is sent with additional error
correcting bits. On reception, the error bits are identified and (usually) corrected.
HD HD: : : : (high definition) This refers to any resolution above the DVB standard resolution. HD HD
The DVB standard resolutions for the luminance signal are (H X V):
720 X 576, 544 X 576, 480 X 576, 352 X 576, 352 X 288
The DVB-S2 High definition resolutions are (H X V) 1920 X 1080 or 1280 X 720. They
can either be interlaced or progressive. Interlaced means the picture is built from two
"fields" with each field being alternating half the scan lines. Progressive means the
entire picture is repeated each time. Progressive pictures require a higher data rate.
IF IF IF IF: (intermediate frequency) This refers to the frequency after down conversion at the
LNB to the range 950 MHz to 2150 MHz.
IQ decision points IQ decision points: During demodulation of a QPSK or 8PSK signal, the two phases of the IQ decision points IQ decision points
are converted to digital data and this data is sampled at the Symbol Rate. These samples
are called IQ decision points (as seen on the constellation diagram) and are then form
the digital input symbols.

Glossary

Bits
Error
 
V
   
dB = 20 log or
V
 
0
36
/ Bits
This is a small number and is
Received
-8
. Typically, BER should be smaller
 
P
   
dB = 10 log
P
 
0