v1.1
UM-R8XDLIM-HY-01
Page 28
Dual Band ICS Repeater User Manual
Suppose maximum output power of repeater is 37dBm and its gain is 95dB:
So, when input power is weaker than -58dBm, output power = Input Power + 95dB
When input power is stronger than -58dBm, output power = 37dBm
4.1.2.2 Link Budget
Below provides an example of calculating the link budget of the repeater system. Note that gain
is 95dB in the picture below.
Figure 14
When the maximum output power cannot be achieved due to low donor signal input availability,
even at maximum gain, the following two approaches will help increase the output power.
1.
Adjust the direction of the donor antenna or change the donor antenna location to receive a
stronger signal
2.
Change the donor antenna to a higher gain donor antenna.
Signal
Strength
Donor
Ant. Gain
Cable
Loss
Repeater
Gain
Repeater
Output
Cable
Loss
Service
Ant. Gain
Path
Loss
Received
Signal
Strength
-85dBm
+16dBi
-2dB
+95dB
24dBm
-1dB
+16dBi
-127dB
-88dBm
Method 1: Increaser Signal Strength
-80dBm
+16dBi
-2dB
+95dB
29dBm
-1dB
+16dBi
-127dB
-83dBm
Method 2: Change donor antenna to a higher gain donor antenna
-85dBm
+21dBi
-2dB
+95dB
29dBm
-1dB
+16dBi
-127dB
-83dBm
4.1.3 UL Noise Floor
For WCDMA system, the thermal noise has the power level of -108dBm, and for LTE system with
10MHz bandwidth, the thermal noise has the power level of -104dBm.
With all amplifier systems including the repeater system, the noise level increases after the