LG U8110 Service Manual page 212

Parameter
PL 5
PL 6
PL 7
PL 8
PL 9
PL 10
PL 11
PL 12
PL 13
PL 14
PL 15
PL 16
PL 17
PL 18
PL 19
G. RSSI and AGC Calibration
- Purpose
This procedure satisfies the two following requirements:
Calibrate an absolute power level on the antenna to a corresponding RSSI value. This value together
with a pre-defined slope figure is then used to calculate the RSSI value of an arbitrary received
antenna power. The formula y=kx+m is used. (Where k is the slope value, x the RSSI value, y the
actual level, and m is an offset value.)
Calculate the attenuation when the Low Noise Amplifier is switched off in the receiver branch. The
attenuation value is stored in the flash memory and used when very high input signals are fed into the
ME.
- Procedure Proposal
1. Select switched receiver on a mid EGSM Channel.
2. Feed a modulated -68.5dBmsignal, on the same mid EGSM-Channel to the antenna input. Measure
the RSSI value, calculate the RSSI table and store the value in GDFS as parameter:
GD_RXLEVS_DBM_BURST_M_BAND.
3. On the same channel, now feed a modulated -50dBmsignal and measure the RSSI value.
Target Full Power (dBm)
33.0
31.0
29.0
27.0
25.0
23.0
21.0
19.0
17.0
15.0
13.0
11.0
9.0
7.0
5.0
Table 8-3. Target Power Levels for EGSM
- 213 -
8. CALIBRATION
Tolerances (dB)
+0.5 – 1.0
±0.3
±0.5
±0.5
±0.5
±0.5
±0.5
±0.5
±0.5
±0.5
±0.5
±0.5
±0.5
±0.5
±0.5
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol