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參數(shù)資料
| 型號(hào)： | ST70135A |
| 廠商： | 意法半導(dǎo)體 |
| 英文描述： | ASCOTTM DMT TRANSCEIVER |
| 中文描述： | ASCOTTM大唐收發(fā)器 |
| 文件頁數(shù)： | 12/29頁 |
| 文件大?。?/td> | 198K |
| 代理商： | ST70135A |
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ST70135A
12/29
In the transmit direction, themapper receives a bit
stream from the Trellis encoder and modulates
the bit stream on a set of carriers (up to 256). It
generates coordinates for 2n QAM constellation,
where n < 15 for all carriers.
The Mapper performs the inverse operation,
mapping a block of bits into one constellation
point (in a complex x+jy representation) which is
passed to the IFFT block. The Trellis Encoder
generates
redundant
robustness
of
the
transmission,
4-Dimensional TrellisCoded Modulation scheme.
bits
to
improve
the
using
a
This
computes error parameters for carriers specified
in the Demapper process.
feature
can
be
disabled.The
Monitor
Those parameters can be used for updates of
adaptive
filters
coefficients,
adjustments, error detection, etc. A series of
values is constantly monitored, such as signal
power, pilot phase deviations, symbol erasures
generation, loss of frame, etc.
clock
phase
Generic TC Layer Functions
These functions relate to byte oriented data
streams. They are completely described in ANSI
T 1.4 13. Additions described in the Issue 2 of this
specification are also supported.
The data received from the demapper may be
split
into
two
paths, one
interleaved data flow the other one for a fast data
flow. No
external
RAM is needed
interleaved path.
dedicated
to an
for the
The
increase the error correcting capability of block
codes for error bursts. After deinterleaving (if
applicable), the data flow enters a Reed-Solomon
error correcting code decoder, able to correct a
interleaving/deinterleaving
is
used
to
number of bytes containing bit errors. The
decoder also uses the information of previous
receiving stages that may have detected the error
bytes and have labelled them with an ”erasure
indication”. Each time the RSdecoder detects and
corrects errors in a RS codeword, an RS
correction event is generated.
The occurrence of such events can be signalledto
the management layer.After the RS decoder, the
corrected byte stream is descrambled in the PMD
(Physical Medium Dependent) descramblers. Two
descramblers are used, for interleaved and
non-interleaved data flows.
These
descrambling, the data flows enter the Deframer
that extracts and processes bytes to support
Physical layer related functions according to ANSI
T1.413.
The
ADSL
frames
physical layer-related information in addition to
the data passed to the higher layers. In particular,
the deframer extracts the EOC (Embedded
Operations Channel), the AOC (ADSL Overhead
Control) and the indicators bits and passes them
to the appropriate processing unit (e.g. the
transceiver controller).
are
defined
in
ANSI
T1.413.
After
indeed
contain
The deframer also performs a CRC check (Cyclic
Redundancy Check) on the received frame and
generates events in case of error detection.Event
counters can be read by management processes.
The outputs of the deframer are an interleaved
and a fast data streams. These data streams can
either carry ATM cells or another type of traffic. In
the latter case, the ATM specific TC layer
functional block, described hereafter, is bypassed
and the data stream is directly presented at the
input of the interface module.
Figure 6 :
Generic TC Layer Functions
DATAPATXMERGER
INTERLEAVER
DE-INTERLEAVER
RS
CODING
DECODING
PMD
SCRAMBLER
DESCRAMBLER
PMD
SCRAMBLER
DESCRAMBLER
F
I
FRAMER
DEFRAMER
F
I
To
ATM
TC
IndicationBits
AOCEOC
To/From
Demapper
FAST
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ST70136 | CPE ADSL ANALOG FRONT END |
| ST70136B | CPE ADSL ANALOG FRONT END |
| ST70136G | CPE ADSL ANALOG FRONT END |
| ST70137 | UNICORNTM PCI & USB CONTROLLERLESS ADSL DMT TRANSCEIVER |
| ST70137TQFP | UNICORNTM PCI & USB CONTROLLERLESS ADSL DMT TRANSCEIVER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ST70136 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:CPE ADSL ANALOG FRONT END |
| ST70136B | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:CPE ADSL ANALOG FRONT END |
| ST70136G | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:CPE ADSL ANALOG FRONT END |
| ST70136Q | 功能描述:射頻無線雜項(xiàng) ADSL Analg Front-End RoHS:否 制造商:Texas Instruments 工作頻率:112 kHz to 205 kHz 電源電壓-最大:3.6 V 電源電壓-最小:3 V 電源電流:8 mA 最大功率耗散: 工作溫度范圍:- 40 C to + 110 C 封裝 / 箱體:VQFN-48 封裝:Reel |
| ST70137 | 制造商:STMicroelectronics 功能描述: |
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