User Guide

PAMS
Technical Documentation
NHB–3
Service Software Instructions
Original 26/97
Page 31
3.2.6 – Noise Sensitivity
This function is used for making Signal to Noise measurement.
The next automatic selections are made when this tuning function is activated:
– active unit = RX
– operation mode = continuous
– AGC = 93 dB in PCS
When this selection is made the next window comes to the display.
Clipping distance is the difference to the signal clipping value. SNR is mea-
sured in A/D converter.
Clipping distance = clipping level (66) – signal value + comp_factor1
SNR = signal value – noise value + comp_factor1
Sensitivity = –92 dBm + 8 dB + comp_factor2 – SNR
The last value on the display is signal power difference between I and Q
branch. The numbers are shown in 0.1 dB accuracy. The error messages,
”OUT OF RANGE”, are shown only if the SNR and/or amplitude difference val-
ues are not acceptable.
SNR <= 18 dB + comp_factor2 – 0.5 dB(=accuracy) ;
Sensitivity >= –102 dBm + 0.5 dB ;
|Si – Sq| > 1dB
When <F2> or <F3> key is pressed, the RX I and Q burst data will be asked.
Text ”SIGNAL MEASURING” or ”NOISE MEASURING” will appear in the mea-
surement window and the following help line will be on the last line: ”The power
level value should be –92 dBm during signal measurement”
Only <Esc> key is accepted during measurement. <Esc> breaks the measure-
ment routine in the PC and returns the program to the state before pressing of
<F2> or <F3>. Normally <Esc> is not needed.