Research On WLAN Chipset System Architecture

WLAN chipset consists of three modules: radio module,base band process module and MAC module. Radio module is used for reducing radio signal frequency which it receives firstly and processing it,also radio module magnifys the power of the signal before its transmit.Base band process module modulate and demodulate the signal.The funtion of MAC module is media access control and encryption.WLAN chipsets can be divided by the numuber of standard implimented,such as single mode,dual-mode and multi-mode.Some technology should be consided for WLAN chipset system level design,such as radio technology,IC partition,process technology of IC.Radio transceiver is the main part of radio module.Three architecture can be selected in radio design :low IF,very low IF and ZIF.To multi-mode WLAN chipset,IC partition determine the chip number of dual-band transceiver and whether the BBP and MAC can be integrated into one chip.Proper process technology of IC can reduce the cost of whole chipset.While CMOS remains the backbone for digital logic,BiCMOS remains the most implemented technology for RF systems.Compared with single mode WLAN chipset,muti-mode chipset has been improved in many way,such as compatibility,cost performance ratio,power consumption,integration.For further reduction of WLAN cost,some function of WLAN need to be integrated upward to host.There are two way to implement "upward integration".First,some or all chips are moved onto the mainbord of host.Second,some function of WLAN are integrated into South Bridge Chip of the host.For the second way,integrating MAC function into South Bridge chip is the most feasible solution.XAUI is used as interface between MAC and PHY,BB and RF simultaneously.The advantage of XAUI can meet the requirement of connections between WLAN modules.