SM ALFOplus - Adaptive Modulation

MN.00273.E - 004 39
- Link ID identifier RFOH: 1 to 255
- Loop facility Baseband loop, RF loop (only for GB8xxxx)
- Spurious emissions/rejection according to ETSI
- Max RSL threshold
- without degradation -25dBm
- without distortion -22dBm
- without permanent damage -10dBm
6.2.1 Adaptive modulation
ALFOplus ODU’s implement an error free adaptive modulation algorithm to improve the system gain when
the quality of the received signal become insufficient to guarantee an error free link.
The thresholds for ACM are shown in the Tab.6
.
Tab.6 - ACM switching thresholds
28 8
32 9.5
38 9
42 10
7M Physical Mode
Power
(Estim.)
BER 10
-6
(Estim.)
Down-shift
(Estim.)
Margin
(Estim.)
Up-shift
(Estim.)
Margin
(Estim.)
Up-shift
(Estim.)
Margin
(Estim.)
4SQAM 0 6.4 13.2 13.2
4QAM 0 8.2 11.2 3 17.7 5 20.2 5.0
16SQAM -2.5 12.7 15.7 3 19.6 5 19.6 7.5
16QAM -2.5 14.6 17.6 3 22.2 5 23.5 5.0
32QAM -3.75 17.2 20.2 3 24.7 5 24.5 6.3
64QAM -3.5 19.7 22.7 3 27.8 5 27.8 4.8
128QAM -3.5 22.8 25.8 3 31 5 31.6 5.0
256QAM -4.125 26 29 3 34.1 5 34.1 5.6
512QAM -4.25 29.1 32.1 3 36.8 5 36.8 5.1
1KQAM -4.25 32.3 35.3 3 4.5 4.5
10M Physical Mode
Power
(Estim.)
BER 10
-6
(Estim.)
Down-shift
(Estim.)
Margin
(Estim.)
Up-shift
(Estim.)
Margin
(Estim.)
Up-shift
(Estim.)
Margin
(Estim.)
4SQAM 0 6.4 0 0 13.2 0 13.2
4QAM 0 8.2 11.2 3 17.7 5 20.2 5.0
16SQAM -2.5 12.7 15.7 3 19.6 5 19.6 7.5
16QAM -2.5 14.6 17.6 3 22.2 5 23.54 5.0
32QAM -3.75 17.2 20.2 3 24.7 5 24.5 6.3
Frequency Band (GHz) Noise Figure (dB)