Televes FI Simple Manual De Instrucciones página 43

01030075_000:103422.QXD 22/07/2009
User manual
To configure each FI DVBS2 PROCESSOR
module that has been switched to "on" , you
will have to use the programmer following
these steps:
If you press the
configuration menu of the first processor
module switched to "on" and so on you will
have to press this key untill you reach the
menu of the active processor that you want
to configure. There is a configuration menu
as the following one for each of them:
PROCESSOR1
Fin:1350MHz
Fout:1500MHz
BW:36 Lev:99
- Fin allows to insert the input frequency.
- Fout allows to insert the output frequency.
The range allowed for input or output fre-
quency values goes from 950 to 2150
MHz.
- BW allows to select the bandwidth by
paths of 2MHz. The margin of values you
can select goes from 10 to 72MHz.
- Lev allows to regulate the output level 15
dB approximately. 99 is the highest level
and 00 is the lowest level.
11:24 Página 43
The
want to modify, increasing or decreasing it
once you select it by using the
keys.
key, you will access the In the BW and Lev parameters you the value
is selected directly using the
keys.
To choose the bandwidth (BW that can be
selected for each processor), you will have
to have into account the transmission speed
of the signal processed, so that the BW
selected is the most suitable bandwidth for
that signal.
The relation between the spectral bandwidth
used and the binary rate (transmission
speed) transmitted is the following one:
BW (MHz)=
Example:
key allows to select each digit you
and
and
Bit rate (bits/s)
x roll_off
Bits/symbol
Modulation BW (MHz ó Msimb/s)
R bits/s
b
x 1,35
QPSK
2 bits/symbol
R bits/s
b
x 1,15
64QAM
6 bits/symbol
43 43
IF Processor
So, for example, if the transmission speed of
the signal you want to process is 27500
Mbaud/s or Msymb/s and the roll-off is 1.35,
the bandwidth required for this sgnal will be
27500 x 1.35= 37125 MHz. You will have to
select a BW=38 for the corresponding pro-
cessor since it is the most appropiate band-
width for this value.
Moreover, to avoid possible interferences
there must be a gap between channels that
will be set as follows: BW selected plus 2
MHz, that means, in this case 38+2=40
MHz. That means that for signals of 27500
Mbaud/s, there must be a gap of at least 40
MHz between the central frequencies of the
output channels.