BCM4330 Preliminary Data Sheet
WLAN PHY Description
CCK/DSSS Demodulate
Filters and Radio
Comp
Frequency and
Timing Synch
Descramble and
Deframe
OFDM Demodulate
Viterbi Decoder
Carrier Sense, AGC, and
Rx FSM
Buffers
MAC
Radio Control Block
FFT/IFFT
Interface
AFE and
Radio
Tx FSM
Modulation and
Coding
Common Logic Block
Frame and
Scramble
Filters and Radio Comp
PA Comp
Modulate/Spread
COEX
Figure 35: WLAN PHY Block Diagram
The PHY is capable of fully calibrating the RF front end to extract the highest performance. On power-up, the
PHY performs a full suite of calibration to correct for IQ mismatch and local oscillator leakage. The PHY also
performs periodic calibration to compensate for any temperature related drift thus maintaining high-
performance over time. A closed loop transmit control algorithm maintains the output power to required level
with capability control Tx power on a per packet basis.
One of the key feature of the PHY is two space-time stream receive capability. The STBC scheme can obtain
diversity gains by using multiple transmit antennas in AP (Access Point) in a fading channel environment,
without increasing the complexity at the STA. Details of the STBC receive is shown in the block diagram shown
in Figure 36 on page 92.
®
BROADCOM
BCM4330 Preliminary Data Sheet
April 28, 2011 • 4330-DS304-RI
Page 91
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