Promax US TV EXPLORER II, User Manual

Page: 68 / 268

USER’S MANUAL. US TV EXPLORER II
Page 60 01/2008
Finally it is shown a status line with information about the detected signal. The
possible messages that can appear and its meaning are showing the following list. The
messages are exposed from less to more fulfillment of the
MPEG-2 standard:
No signal received
No signal has been detected.
Timing recovered
Only it is possible to recuperate the symbol time.
AFC in lock
The system automatic frequency control can identify and lock a digital
transmission (TDT) but its parameters can not be obtained. It can be due to a
transitory situation previous to the TPS identification (
Transmission Parameter
Signaling ) or well to a TDT transmission with an insufficient C/N ratio.
TPS in lock
The TPS ( Transmission Parameter Signaling ) are decoded. The TPS are carriers
containing information related to the transmission, modulation and codification:
Modulation type, Viterbi Code Rate, and Number of the received frame.
MPEG-2
Correct detection of a MPEG-2 signal.
5.14.7.4 DVB-S/S2 and DSS signals
Once determined the parameters of QPSK signal, it will be possible to measure
BER . Following is shown the BER measurement before the error corrections : BER
before the FEC : CBER .
-6 -5 -4 -3 -2 -1
FREQ:
DL-Ku:
CH:
C/N:
POWER:
MER:
CBER:
VBER:
»
0.2
51.5
10.9
dB
dBµV
dB MHz
kHz
MHz
1781.94
12382.0
5037
99 9.7E-4
5.2E-8
MPEG-2 TS
Figure 38.- Screen of CBER measurement ( QPSK signals).