Panasonic EB-X400 Service Manual page 24

Uplink / Downlink I & Q
U2001 (E-Gold + V3) performs GMSK modulation on data samples received form DSP at 270 Kbits per second.
The I & Q signals are multiplexed to interface with the SMARTi RF IC.
Earpiece
Ringer
and Channel
DAC
Car Kit
and Channel
ADC
1 2 3
4 5 6
7 8 9
0 #
Figure 5.4. Functional structure of the baseband Uplink / Downlink path
Power amplifier Ramp
The PA control ensures that the power ramp up and down sequences are generated. Each power ramp up/down sequence
consists of 16 values of 10-bit length which represents the shape of the rising (falling) edge of the desired ramping curve in
digital form. All 10-bit values are delivered in serial manner to the power-ramping path of GAIM.
Shape
The Ramp Shape is defined by 16 steps, the shape can be defined differently for rising and falling ramps.
Typically a raised cosine shape will be used as a starting basis of the ramp shape.
TOUT(i)
trig_start
RFSTR(5)
GAIM_CLK
GAIM_DATA
PAOUT
0 V
ADC
Speech
Equalizer
Decoding
ADC
Viterbi HW GSM
OAK+
Accelerator Cipher Unit
DAC
Speech
GSMK
Modulator
Encoding
DAC
E-GOLD + V3
(PMB7850)
Interfaces
Realtime
GSM
SSC
Clock
Timer
2
I C
Power
GPRS Unit
Mgmt.
DAI
MMC
C166S
Infineon 16-Bit Core
Blue
tooth IF
ramp up
1 2 3 15 16
Figure 5.5. Raised and fall cosine for the PA ramp
I
Automatic
Compensation
Q
CLK
DAT
Control
ENA Logic
AFC
DAC
26 MHz
2
I S
JTAG
ASC
IrDA
RF Control
Display
ramp down
17 18 30 31 32
– 5-11 –
GSM 900/1800
Offset
only for
GSM 1900
Tri-Band
SMARTi-DC-3
(PMB6257)
SAM
Fast PLL
FLASH
Rx/Tx
Power
Amplifier