BCM3118B Datasheet, PDF (2/2 Pages) Broadcom Corporation. – QAMLINK DVB/DAVIC RECEIVER

BCM3118B OVERVIEW
A_IF+/-
10
A/D
Variable
Rate
Demod
Nyquist
α = .13-.15
Nyquist
α = .13-.15
AGC_CTRL
BAUD_CTRL
IF_OSC
GEN_CTL
Acquisition/Tracking Loops
and Clock Generation
Phase
Recovery
and
8-Tap
FFE
4_I
12-Tap
DFE
Reed-
Solomon
Decoder
(204, 188)
t=8
cos ωn
sin ωn
Phase
ROM
JTAG
4_Q
Tuner
Control
Deinterleaver
RAM
MBus/SPI
Interface
PS_DATA
LPS_CLK
LPS_SYNC
LPS_DATA [7:0]
PS_ERR
RAM_CTRL
MICRO [3:0]
The BCM3118B QAMLink DVB/DAVIC Receiver with FEC is
an integrated digital transmission solution for cable modems,
cable-TV set-top boxes and digital microwave radios. Its
bandwidth-efficient feature set expands the existing potential
bandwidth of a standard analog network and provides operators
with reliable, error-free transmission. Optimized for high-
volume manufacturing, the BCM3118B is a highly integrated
solution that reduces the system-level chip count, the cost, and
the complexity associated with manufacturing RF receivers.
A single-chip solution, the BCM3118B has a 10-bit A/D
converter, a 256-QAM demodulator with square-root raised-
cosine receive filters, an adaptive equalizer with an embedded
phase recovery derotator, acquisition and tracking loops, and a
DVB/DAVIC-compliant Reed-Solomon FEC decoder with
deinterleaver. The demodulator supports QPSK, 16, 32, 64, 128
and 256-QAM formats and adapts to channels encoded at
different data rates up to 56 Mbps. The equalizer in the
BCM3118B achieves transmission performance within 1 dB of
theory over worse-case channels with multipath delays as long as
2.4 microseconds at 5 MBaud or 1.7 microseconds at 7 MBaud
and amplitudes within .5 dB of the desired signals. With this
level of performance, the BCM3118B combats the effects of
channel distortions commonly found in cable-TV systems. The
JTAG [3:0]
RF [5:0]
BCM3118B has an integrated A/D converter, which eliminates
the costs associated with fine tuning of external components
during high-volume production.
The BCM3118B samples the analog IF waveform being
delivered to BCM3118B by the integrated A/D converter. The
signal is then digitally mixed to baseband and filtered by dual
square-root Nyquist filters. Inter-symbol interference is then
removed by the adaptive decision feedback equalizer. A decision
slicer, which supports constellations up to 256-QAM, formats the
equalized data. The data is then fed into a DVB/DAVIC-
compliant synchronization block, deinterleaver, Reed-Solomon
FEC, and derandomizer. The final error-corrected output is
delivered in an MPEG-2 transport format.
The BCM3118B can be used as a stand-alone chip or with
Broadcom's BCM3250 for a complete watch and record solution
with EuroDOCSIS. Compliant with the ITU-T J83/Annex A and
Annex C, DVB/DAVIC and the IEEE802.14 cable transmission
standards for QAM downstream, the BCM3118B is a universal
downstream solution for worldwide coaxial cable applications.
Broadcom^®, the pulse logo, QAMLink^® and Connecting everything^® are trademarks of
Broadcom Corporation and/or its subsidiaries in the United States and certain other countries.
All other trademarks are the property of their respective owners.
®
BROADCOM CORPORATION
16215 Alton Parkway, P.O. Box 57013
Irvine, California 92619-7013
© 2003 by BROADCOM CORPORATION. All rights reserved.
3118B-PB05-R-06.13.03
Phone: [phone]
FAX: [phone]
Email: [e-mail]
Web: www.broadcom.com