BCM4322 PCI Express卡系统方案

Broadcom公司的BCM4322无线LAN芯片是第二代Intensi-fi技术,它和IEEE 802.11n draft 2.0标准兼容.最大数据速率可达300Mbps,实际吞吐量超过200Mbps,超过现有802.11n解决方案以及大多数网络产品的能力.BCM4322集成了802.11媒体接入控制器(MAC),基带处理器,2.4GHz和5GHz无线电以及其它WLAN元件,节省BOM成本多达40%.本文介绍了BCM4322的主要性能和指标,系统方框图以及PCI Express卡系统图.

Broadcom Delivers Worlds First Single-Chip 802.11n Solution
The BCM4322 wireless LAN chip is the second generation of Broadcoms popular Intensi-fi technology that complies with the IEEE 802.11n draft 2.0 specification. With a unique architecture, Broadcoms new WLAN chip offers a maximum data rate of 300 Mbps with actual throughput of over 200 Mbps -- which exceeds the capabilities of existing 802.11n solutions and the most wired networking products. The BCM4322 also employs innovative techniques to provide more reliable wireless connections and increase the coverage area of a wireless network. This additional performance and range will enable Wi-Fi users to quickly transfer videos, photos, music and large data files between wireless devices throughout a home or office.

The BCM4322 is the only 802.11n solution to combine an 802.11 medium access controller (MAC), a baseband processor, 2.4 GHz and 5 GHz radios and other WLAN components onto a single silicon die. This high level of integration reduces the number of components required for a WLAN subsystem by two-thirds, which can lower a manufacturers bill of materials (BOM) cost by up to 40 percent. It is also the first 802.11n solution to be designed using 65 nanometer CMOS processes.

特性：

Single-chip all-in-one die Baseband/MAC/Radio for 2x2 802.11n applications
Advanced 65 nm CMOS process for lowest power consumption and highest integration
802.11n Draft 2.0 compliant Wi-Fi™ solution. Fully compatible with IEEE 802.11n Draft 1.0 and 802.11a/b/g legacy devices.
Two transmitters and two receivers with optional 802.11n. Draft 2.0 modes allow data rates supporting 300 Mbps.
Flexible two and three antenna configurations for improved range and performance
Support for optional 802.11n features for improved rate, range performance
Greenfield preamble
Space Time Block Code (STBC)
Short Guard Interval
Multiple Host Interfaces supported: PCIe, PCI, mPCI, USB 2.0 (BCM94323 only)
Integrated ARM Cortex M3 CPU for USB host offload
Low RBOM count and optimal packaging for cost effective PCB designs
High-performance 802.11a/b/g/n features standard across the Intensi-fi and AirForce product lines
OneDriver
Single driver across platforms simplifies driver update process and improves customer satisfaction
BroadRange
Afterburner high-speed modes
High-performance whole home coverage
SecureEasySetup and Wi-Fi protected set-up for simple wi-fi setup and security configuration
WPA/WPA2
Cisco Compatible Extensions (CCXv4, CCXv5)
Full-rate AES engine in hardware
WMM for quality of service
表1.BCM4322指标

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图1.BCM4322系统方框图.

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图2.BCM4322 PCI Express卡外形图.