User Manual

AS8100 Sitespan User Guide Version 3.7
605-0000-426
DLP 069
Draft Issue 6.0 Date 4/4/00
Page 217 of 305
0
5
-25
0.7
1.3
1.7
4
3
2
1
PC
Volts
TX Level (dBm)
TX PC Equalised Characteristic
3.4-3.6GHz
+25 0+20 +10 -10 -20
10dB Fade Margin
6dB Fade
Margin
0dB Fade
Margin
+18 +12 +8
• The Uplink Code Phase The value shown in the Sitespan ST View Uplink
Code Phase is an indication of how much the ST transmit waveform has been
time advanced in order for it to be received at the CT time synchronised with
the downlink waveform, and may be used to compute the distance between an
ST and the CT.
• The range of the uplink code phase values is 0 to 4095. Uplink code
phase is measured in sixteenth-chips where 1/16th chip is equivalent to
24.414 ns. Multiplying the uplink code phase value by 24.414 ns yields
the approximate round trip delay from the CT to the ST and back to the
CT.
• For an ST located within 14829m of the CT, approximate ST range is
computed as follows;
Range = (Uplink Code Phase -50) * 3.666 m
The correction of -50 made to the uplink code phase value is included to
take account of the fixed delay within the AS4000 system.
• For an ST located between 14830 and 29850m of the CT, approximate
ST range is computed is modified to take account of the wrap-around in
uplink code phase when the value reaches 4095;
Range = (Uplink Code Phase + 4046) * 3.666 m
• Uplink code phase accuracy is +/- 3/4 chip which corresponds to a
ranging accuracy of +/- 44m.
STOP. THIS PROCEDURE HAS BEEN COMPLETED.