User guide

45 Mbps Backhaul User Guide
Issue 3, December 2004 Page 81 of 113
The receive sensitivities and system gains for each mode are as follows:
Mode
RX Sensitivity
TX Power
System Gain
BPSK 1/2
-95.5 dBm
24 dBm
166.5 dB
QPSK 1/2
-92.8 dBm
23 dBm
162.8 dB
QPSK 2/3
-90.7 dBm
23 dBm
160.7 dB
16QAM 1/2
-88.1 dBm
21 dBm
156.1 dB
16QAM 3/4
-83.6 dBm
21 dBm
151.6 dB
64QAM 2/3
-80.2 dBm
19 dBm
146.2 dB
64QAM 3/4
-78.3 dBm
19 dBm
144.3 dB
64QAM 7/8
-73.6 dBm
19 dBm
139.6 dB
The values quoted here are static sensitivity measurements. When AMOD is in operation, margins are applied
to the up and down shifts between modes to ensure seamless changes without loss of data. The margins applied
are dynamic and selected dependant on the prevailing link conditions.
The margins applied are as follows:
Fading
Mode Up Shift
Mode Down shift
Slow
1.5 dB
1.5 dB
Fast
6 dB
3 dB
For example: In a fast fading environment an up shift from 16QAM _ to 64QAM 2/3 will occur at –74.2 dBm (-
80.2 dBm + 6 dB) and the down shift from 64QAM 2/3 to 16QAM _ will occur at –77.2 dBm (-80.2 dBm + 3
dB).