Sony-Ericsson T610 Service Manual
Prepared (also subject responsible if other) No.
SEM/GUR/BRR Pontus Nelderup 1/1551 - ROA 128 0351/2
Approved Checked Date Rev Reference
SEM/GUR/BRRC Mikael Nilsson 2003-02-28 B
DESCRIPTION
Technical Description: T610 Radio on the Tranceiver
Board
Contents:
1 (16)
1 GENERAL...............................................................................................................................................................................................2
1.1 CROSS REFERENCES................................................................................................................................................................2
1.1.1 Names ..........................................................................................................................................................................................2
1.1.2 Abbreviations.............................................................................................................................................................................3
2 OVERVIEW ...........................................................................................................................................................................................4
2.1 THE TX PATH ..............................................................................................................................................................................4
2.2 THE RX PATH..............................................................................................................................................................................5
3 FREQUENCY PLAN ...........................................................................................................................................................................6
4 THE RADIO BLOCKS ........................................................................................................................................................................7
4.1 THE ANTENNA SWITCH...................................................................................................................................................................7
4.2 THE RECEIVER................................................................................................................................................................................8
4.2.1 RF filter and balun ....................................................................................................................................................................8
4.2.2 Receiver front-end.....................................................................................................................................................................8
4.2.3 VCO .............................................................................................................................................................................................9
4.2.4 Sigma delta A/D Converter...................................................................................................................................................10
4.2.5 Digital filter ..............................................................................................................................................................................10
4.3 THE TRANSMITTER.......................................................................................................................................................................11
4.3.1 Frequency synthesis and modulation ...................................................................................................................................11
4.3.2 Direct modulation and frequency synthesis ........................................................................................................................12
4.3.3 Phase detector.........................................................................................................................................................................12
4.3.4 Prescaler...................................................................................................................................................................................12
4.3.5 Charge pump and pulse skip detector.................................................................................................................................13
4.3.6 Loop filter.................................................................................................................................................................................13
4.4 POWER AMPLIFIER & POWER CONTROL BLOCK:......................................................................................................................14
4.5 THE V OLTAGE CONTROLLED X-TAL OSCILLATOR (VCXO): ................................................................................................ 15
4.6 POWER MANAGEMENT ................................................................................................................................................................15
4.7 BLUETOOTH...................................................................................................................................................................................15
5 PRINTED CIRCUIT BOARD .........................................................................................................................................................16
Prepared (also subject responsible if other) No.
SEM/GUR/BRR Pontus Nelderup 1/1551 - ROA 128 0351/2
Approved Checked Date Rev Reference
SEM/GUR/BRRC Mikael Nilsson 2003-02-28 B
DESCRIPTION
1 GENERAL
This document describes radio solution, which is part of the transceiver board
mounted in the GSM pocket phones.
The other part of the transceiver board that carries the base band part is
described in the corresponding document 2/1551-ROA 128 0351/2.
The primary purpose of the radio part is to transfer the information to and from
the base stations without distortion, and to handle the large dynamic range of
the signals that occur during normal use.
2 (16)
• Section 2 is the data flow through the phone described in both TX and RX
direction.
• In section 4, several of the electrical functions and circuits are described
in more detail.
• In section 5 the layer structure of the PCB is briefly described.
1.1 CROSS REFERENCES
1.1.1 Names
In most cases the different components in the phone are given names which
are used during the development phase. These names are also used in this
description.
The following list shows the used component names and the corresponding
position numbers used in the schematics.
Prepared (also subject responsible if other) No.
SEM/GUR/BRR Pontus Nelderup 1/1551 - ROA 128 0351/2
Approved Checked Date Rev Reference
SEM/GUR/BRRC Mikael Nilsson 2003-02-28 B
DESCRIPTION
Ingela N201
Victoria 2+ N800
Power amplifier N340
13MHz xtal B201
Antenna switch N100
GSM SAW filter Z103
DCS SAW filter Z101
PCS SAW filter Z102
Voltage regulator N250
3 (16)
Martha D600
Herta N660
Ran – Bluetooth RF Module N900
1.1.2 Abbreviations
Some common abbreviations are used in the text. These are explained below.
A/D Analogue/Digital
HW Hardware
MS Mobile Station
PCB Printed Circuit Board
RF Radio Frequency
RSSI Received Signal Strength Indicator
RX Receive
TAE Terminal Adapter Equipment
TX Transmit
Power control
filtering
INGELA
SAW-filters
D
switch
DESCRIPTION
Prepared (also subject responsible if other) No.
SEM/GUR/BRR Pontus Nelderup 1/1551 - ROA 128 0351/2
Approved Checked Date Rev Reference
SEM/GUR/BRRC Mikael Nilsson 2003-02-28 B
2 OVERVIEW
A general block diagram that describes the GSM phone is shown in the figure
below. It shows the signal flow through the phone, and indicates the different
hardware parts involved in the transmission and reception.
4 (16)
B
A
S
E
B
A
N
All names below the boxes in figure correspond to the project names of the
component that performs the indicated operation.
The component that controls the data flow has the project name MARTHA
and is located in the baseband block. It acts as the Central Processing Unit
containing an AVR microprocessor, DSP, internal RAM and the interfaces to
external components and units as the external memories and the radio. It also
performs the signal processing not done in the other parts.
2.1 THE TX PATH
Modulation, and
channel selection Amplification
INGELA
channel
MixerCoarse
Low Noise
Amplifier
Power
amplification &
PA + Victoria2
Band filtering
Figure 2.1 Block diagram for GSM phone.
TX / RX
switching
Antenna
The speech signal from the microphone is amplified and digitized to a 16 bitPCM signal in HERTA. It is then sliced into 20 ms pieces and thereafter
speech coded in DSP to reduce the bit rate. Further data processing is carried
out in MARTHA that includes channel coding, interleaving, ciphering and
burst formatting. The data is then put through a wave form generator (IQ
signal) before it is fed to the radio.
The RF-ASIC INGELA is the heart of the radio. It has an integrated direct
modulation transmitter where the channel selection and modulation is applied
in one stage via a fractional -N type of synthesizer. The information is added
via the divider ratio of the synthesizer. INGELA also amplifies the signal and
buffers it before it is sent to the power amplifier. The buffer amplifier can be
turn on & off, and it is used to secure pre burs output power. The power
amplifier and VICTORIA 2+ are connected in a control loop that makes the
power ramping, and controls the output power.
Prepared (also subject responsible if other) No.
SEM/GUR/BRR Pontus Nelderup 1/1551 - ROA 128 0351/2
Approved Checked Date Rev Reference
SEM/GUR/BRRC Mikael Nilsson 2003-02-28 B
DESCRIPTION
2.2 THE RX PATH
5 (16)
Log-
Polar
Conv.
Ingela
LO
Analog
LP filter
Σ∇
ADC
Digital-
filter
Herta Martha
DC
Comp.
Figure 2.2: Receiver block diagram.
The signal received by the antenna is fed trough a band pass filter and
directly into Ingela. The RX part in Ingela contains a direct conversion
receiver and the RF signal is mixed down to base band in one step. Except
for the RF filter, all filtering except for the anti-aliasing filtering is done in
baseband domain. The main part of channel filtering is in other words done in
the digital domain.
The signals IRA, IRB, QRA and QRB from the radio are hard limited phase
modulated and differential signals that contain all the data received. A fast
phase digitizer in HERTA, demodulates these signals and the phase
information is then fed to MARTHA.
The handling of the DC-level is a big difference compared to the super
heterodyne receiver. (The received signal is mixed with the same frequency
that will give a DC-signal and the signal information) The DC component has
to be removed before detection otherwise the ADC could be saturated, which
would completely destroy the information.
The first step in MARTHA is an equalizer that uses a Viterbi algorithm to
create a model of the channel. Then the received bursts are further processed
to decipher the information. After the de-interleaved (collection and
reassembling all eight “half bursts” into a 456 bit message), the sequence is
decoded to detect and correct errors during the transmission. The decoder
uses soft information (probability that a bit is true) from the equalizer to
improve error correction.
Finally the bit stream is speech decoded in the DSP and then transformed
back into analogue speech in HERTA.
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