9
- Guard interval:
1/32, 1/16, 1/8, 1/4;
- Hierarchical modulation:
=1,
=2,
=4;
- FEC:
1/2, 2/3, 3/4, 5/6, 7/8;
- MER measurement range (QAM64, FEC=3/4):
18 to 35 dB;
- MER measurement resolution:
0.1 dB;
- MER measurement accuracy within the working range of
input signal power:
±2.0 dB;
- BER measurement range:
- BER before Viterbi decoder:
1,0x10
-2
to 1,0x10
-8
;
- BER after Viterbi decoder:
1,0x10
-3
to 1,0x10
-8
;
- DVB-T/H channel real power threshold (BER<2.0x10
-4
):
- QAM64, FEC=3/4, S/N=60 dB:
40 dB
μ
V;
- Frequency auto tuning step:
±0.5 MHz;
- Frequency indication:
6 characters on LCD;
- Channel number indication:
3 characters on LCD;
- Signal level indication:
4 characters on LCD;
- Warm-up time:
10 min.;
- IT-088 can be powered by:
- AC circuit with 220 ± 22 V voltage, 50 ± 0.5 Hz
frequency with no more than 5% harmonic content, via
PS12/0.8 Mains Adapter;
- external DC source with 12 ± 0.6 V voltage, and no
more than 0.5 V ripple;
- batteries with capacity at least 2100 mAh;
-
Current consumed from external power source or
batteries:
0.8
А
;
- Continuous stable operation under normal conditions
(when powered by external source):
24 hrs;
- Battery duration under normal conditions (2100 mAh
battery capacity):
6 hours;
- Mean time between failures, no less than:
10000 hours;
- Average lifetime, no less than:
5 years;
- Dimensions:
200x90x55 mm;
- Package dimensions:
400x300
ч
90 mm;
- Weight:
0.6 kg;
- Weight in package:
2.2 kg.
2.6. Design and Operation Overview
2.6.1. Principle of Operation
The Digital DVB-T/H Signal Analyzer is a receiver of DVB-T/H signals with
demodulation of the traffic stream to MPEG-2. The input tuner is a super heterodyne
receiver with triple frequency conversion (auto or manual frequency tuning). Modulation
error ratio MER and constellation diagram are measured in the process of COFDM signal
demodulation based on vector analysis. Bit error rate BER in digital stream is determined
by means of analysis of Viterbi decoder operation (BER before the Viterbi decoder) and
Reed-Solomon decoder operation (BER after the Viterbi decoder). Channel power is
measured by means of analog-to-digital converter after signal peak detection at output of
logarithmic detector of the amplifier of the third IF. The principle of spectrum analyzer is
based on sequential analysis method with spectrum indication on the LCD of the Analyzer
or on PC.
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