Huawei MA5833-BS60 Commissioning Manual page 31

MA5833-BS60
Hardware Commissioning Guide
Because ATT1 = AMP2 total output power P
the following information is obtained: ATT1 = 68.6 – 66 ≈ 3 dB.
Because ATT1+ATT3=6.9≈7 and ATT2+ATT3=2.1≈2, the result is: ATT3 = 4 dB, ATT2 = –
2 dB.
Calculating the Total Output Power of AMP1
Take the channel (channel 114) whose center frequency is 114 MHz as an example:
1.
2.
After the levels of all channels at the AMP1 output point are calculated, calculate the total
output power at AMP1 using the following formula: P
Lamp1_ch120/10
10
output power of AMP1 is 72 dBmV. Therefore, the total output power of AMP1 is not
saturated.
Configuring manual adjustment of the downstream output power
Run the cable rf-power frameid downstream command to set the adjustment mode to
manual, and configure values of ATT1–ATT3 and EQ1–EQ2. The following table describes
the parameters.
Parameter
adjust-mode adjust-mode
docsis--attenuation docsis-attenuation
Issue 01 (2018-12-12)
NOTE
l The center frequencies of the 32 DOCSIS3.0 channels are 114 MHz, 120 MHz, 126 MHz... and 300
MHz, respectively.
l The center frequencies of the 32 EQAM channels are 309 MHz, 312 MHz, 315 MHz... and 495
MHz, respectively.
l The center frequencies of the 20 CATV channels are 683 MHz, 689 MHz, 695 MHz... and 797 MHz,
respectively.
l One DOCSIS3.1 OFDM channel is equivalent to 32 6-MHz channels whose center frequencies are
803 MHz, 809 MHz, 815 MHz... and 989 MHz, respectively.
NOTE
When the attenuation becomes a negative value, increase
end. Alternatively, you can decrease the power of ATT3 and increase the power of ATT1 and ATT2.
Level of the RF OUT port: L
Therefore, L ≈ 30.46 dB.
ch114
NOTE
l 18 is the downstream equalization.
l 85 is the lowest frequency of the downstream frequency band.
l 48 is the transmit level of the RF OUT port@1218 MHz.
Level of the AMP1 output point: L
L ≈ 41.96 dB.
amp1_ch114
NOTE
–11.5 is Gain from the AMP1 output point to the RF OUT point.
Lamp1_ch989/10
... 10
Copyright © Huawei Technologies Co., Ltd.
6 Configuring Intelligent RF Adjustment
– Saturated output power of AMP2,
amp2_total
output power of digital TV signals at the Rx
= 18/(1218 – 85) x (114 – 85) + 48 – 18.
ch114
= L
amp1_ch114 ch 114
amp1_total
). Therefore, P
amp1_total
Adjustment Item
manual
7
– (–11.5 dB). Therefore,
Lamp1_ch114/10
= 10 x lgΣ(10
≈ 71.54 dBmV), and the saturation
,
28