TANDBERG TT1280, Reference Manual

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Technical Specification
Page B-8 Reference Guide: TT128x High Definition Professional Receiver/Decoder
ST.RE.E10141.5
Parameter Specification
Modulation
Signal type QPSK per EN 300 421
3
Convolutional FEC rates 1/2, 2/3, 3/4, 5/6, 7/8
Symbol rate range Rs = 1.0 to 45.0 MSymbol/s
Symbol rate step 1 Symbol/s
Symbol rate lock range
±
120 ppm
Bit-rate R188 range See Table B.8 for QPSK bit-rate R188 limits
Eb/No ratio See Table B.7
Miscellaneous
Phase noise tolerance
SSB phase-noise power spectral density < K + 8.5*Log(Rs) 4 (typical)
at
δ
F = 10 kHz
Phase noise power spectral density of the form C – 20*Log(
δ
F)
δ
F = Frequency offset from carrier
Rs = Symbol-rate (Msymbol/s)
Convolutional FEC rate
K
1/2 -77
2/3 -74
3/4, 5/6, 7/8
-71
LNB power and control See Table B.9
Table B.7 shows the Eb/No requirements to ensure error free demodulation
for all supported FEC rates.
Table B.8 shows the minimum and maximum possible bit-rates for all FEC
rates.
Table B.7: QPSK L-band Satellite Input — Eb/No Ratio
Convolutional FEC Rate Eb/No Ratio (dB) in IF Loop for correct MPEG-2 system
operation
1/2 4.5
2/3 5.0
3/4 5.5
5/6 6.0
7/8 6.4
Eb/No ratio is referred to user bit-rate Ru188. See EN 300 421
specification. For more detailed specification information and advice on
performance in specific applications, please contact TANDBERG Television
Customer Services.
3
EN 300 421: Digital broadcasting systems for television, sound and data services; Framing structure, channel coding
and modulation for 11/12 GHz satellite services.
4
These specifications apply in the presence of thermal noise at the threshold Eb/N
0
ratio given in Table B.7.