LG F3000 Service Manual page 31

3. TECHNICAL BRIEF
3.5.1 Baseband Transmit Section
1. The AD6537B Baseband Transmit Section is designed to support GMSK for both single-slot and
multi-slot application.
2. The AD6535 includes a digital GMSK modulator which is used for GSM application. The GMSK
modulator uses a ROM lookup table to modulate the serial data stream ffrom the BSPORT. The
GMSK modulator is based on 3GPP TS 45.004 ver.5.1.0 Release 5
AD6535
BSIFS
BSDI
CSFS
CSDI
CSDO
3.5.2 Baseband Receive Section
1. This section consists of two identical ADC channels that process baseband in-phase(I) and
quadrature(Q) input signals.
AD6535
BSOFS
Baseband
BSDO
Baseband
Serial
Port
GMSK
Modulator
Ramp
Control
RAM
Serial
Port
Figure 3-9. AD6535 BASEBAND TRANSMIT SECTION
Digital Rx
Filter
ADC
Serial
Port
Rx
Digital
ADC
Filter
Figure 3-10. AD6535 BASEBAND RECEIVER SECTION
SC
Tx Active
Filter CT Filter
DAC
SC Active
Tx
DAC Filter CT Filter
Active
Ramp SC
DAC Filter CT Filter
IP
SC
Filter
IN
QP
SC
Filter
QN
- 32 -
IP
PGA
IN
QP
PGA
QN
PGA
PA
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