BCM2200 FEATURES
IF
Interface
DS Data
US Data
A/D
ODU CTRL & STAT
LO
ODU
D/A
Tx/Rx ODU
Rx ODU
(optional)
TCXO
A/D
FLL CTRL
IF AGC
Analog Module
DC
Up/Down
Conversion
BCM3310
BCM5201
10/100BT
XCVR
Ethernet
SDRAM FLASH
RJ-45
USB
Serial 1,2
USB
ODU
DS
US
BCM2200
VOFDM Rx
OFDM Tx
MAC
2
Wireless Modem Reference Design
•Advanced VOFDM architecture specifically designed
for broadband wireless
•High performance in time-varying multipath channels
•Operates in non-line of sight environment for improved
coverage
•Supports dual antenna for spatial diversity
•OFDM for frequency diversity
•Symmetric downstream/upstream service up to 48
Mbps each way
•MAC designed to improve performance in the wireless
environment
•Enables high-speed full-service connection for data, voice
and video
•Provides statistical multiplexing on channel to increase
effective capacity
•Rapid RF power control to combat flat fading and crosstalk
•Supports connection based isochronous telephony
•Provides contention free data transmission
•Enables network management to match transmission mode to
deployment environment
•Single-chip PHY/MAC
•Reduces overall system cost
•Simplifies system, board and software design
•Reduces power consumption
•Configurable microcontroller interface to support
either full PCI bus master capability or interface to
PowerPC and BCM3310 Broadband Communications
Processor
SUMMARY OF BENEFITS
BCM2200 SINGLE-CHIP WIRELESS MODEM
PRODUCT
Brief
BCM2200
•Dual Vector Orthogonal Frequency Division
Multiplexing (VOFDM) Receivers with Integrated FEC
•Up to 71 Mbps data rate
•Variable channel width up to 15 MHz
•Up to 1024 tones
•4-, 16-, 64-, 256-QAM
•Channel estimation and acquisition
•Integrated OFDM Burst Transmitter
•Up to 48 Mbps data rate
•Variable channel width up to 15 MHz
•Up to 512 tones
•4-, 16-, 64-QAM
•Integrated Media Access Controller (MAC)
for Wireless Applications
•Supports enhanced Quality of Service (QoS) for
Voice over IP (VoIP) applications
•Support for
fragmentation and concatenation
•Support for 16 unicast destination addresses and
256 multicast address filters
•Dedicated SID for closed loop power control
•Inline 40/56 DES encryption/decryption for user data privacy
•Locks 8 kHz subscriber voice clock to base station reference
•CPU Interface
•BCM3310 Broadband Communications Processor
•PCI Master
•PowerPC 850
•1.8V, 3.3V I/O
•320-pin BGA Package
The Broadcom®BCM2200 combines a VOFDM receiver, an
OFDM burst transmitter and a full-featured MAC integrated into
a single chip. The BCM2200 is the first single-chip modem
designed specifically for broadband wireless applications.
The downstream input channels are first finite impulse response
(FIR) filtered to eliminate out of band energy. Frequency locked
loop (FLL) and automatic gain control (AGC) and control
signals are generated to ensure proper synchronization and set
the received signal level. FFTs are calculated and provided to a
channel estimation algorithm. Input FFT and channel estimation
data are then combined in a patented spatial receiver combining
algorithm that produces a single set of soft decision bits to be
processe by the FEC decoder. A concatenated Viterbi-Reed
Solomon FEC makes use of signal-to-interference-plus-noise
metrics calculated from the OFDM signal to improve decoded
BER performance. A MPEG-2 compliant stream is passed to the
MAC downstream processor.
The burst transmitter interfaces to the MAC upstream processor
and has the ability to process high-speed data up to 48 Mbps.
The transmitter can operate with burst or continuous data. It
performs concatenated convolutional-RS encoding and then
processes the data through an IFFT for OFDM transmission.
On-chip smoothing filters pre-filter the data prior to sending to
an external D/A.
The BCM2200 includes an integrated Media Access Controller
(MAC). The MAC enables Quality of Service (QoS) features.
This allows for time sensitive applications such as voice and
video conferencing to coexist with other data traffic while
meeting strict latency requirements. Several hardware functions
support QoS requirements. These include 16 separate upstream
queues, traffic prioritization, fragmentation, and concatenation.
The MAC supports baseline privacy encryption and decryption,
transmission sublayer support, a TDM/TDMA framer, and a
scatter gather DMAinterface. The MAC has also been enhanced
to provide higher bandwidth upstream data capability and
dedicated SIDs for high update rate power control.
The BCM2200 is designed for flexibility by including a
microcontroller interface that can be operated as a PCI bus or
as a microcontroller interface to the BCM3310 Broadband
Communications Processor and PowerPC processors.
BCM2200 OVERVIEW
IFFT
FIR Filtering
& Interp Encoding &
Interleaving
FFT
FIR
Filtering
& Decim
Beamforming
& Demod Decoding &
Deinterleaving
SINR
Metric
Calc
Upstream
Downstream
BCM2200
From A/D
From A/D
2AGC
IF AGC
CTRL
FLL
CTRL
Synch
CPU and PCI
Interface
SDRAM
JTAG
Interface
Modem
ODU CTRL &
STAT
To D/A
Controller
Channel
Est
Downstream
DES
Downstream
Header
Processor
DMA
and
Memory
Interface
Upstream
Header
Processor
Upstream
DES
Upstream
TDMA
Controller
MAP
Processor
Message
Processor
For more information please contact us at:
Phone: 949-450-8700, FAX: 949-450-8710
Email: info@broadcom.com
Visit our web site at: www.broadcom.com
© 2001 by BROADCOM CORPORATION. All rights reserved.
2200-PB01-R-4.23.01
Broadcom and the pulse logo are registered trademarks of Broadcom Corporation
and/or its subsidiaries in the United States and certain other countries.
BROADCOM CORPORATION
16215 Alton Parkway, P.O. Box 57013
Irvine, California 92619-7013
