Document Number: 002-14826 Rev. *G
Page 25 of 65
PRELIMINARY
CYW43903
7.3 IEEE 802.11
™
b/g/n PHY
The CYW43903 WLAN digital PHY complies with IEEE 802.11b/g/n single-stream specifications to provide wireless LAN connectivity
supporting data rates from 1 Mbps to 72 Mbps for low-power, high-performance, handheld applications.
The PHY has been designed to work in the presence of interference, radio nonlinearity, and various other impairments. It incorporates
optimized implementations of filters, FFTs, and Viterbi-decoder algorithms. Efficient algorithms have been designed to achieve
maximum throughput and reliability, including algorithms for carrier sensing and rejection, frequency/phase/timing acquisition and
tracking, and channel estimation and tracking. The PHY receiver also contains a robust IEEE 802.11b demodulator. The PHY carrier-
sensing algorithm provides high throughput for IEEE 802.11b/g hybrid networks with Bluetooth coexistence.
The key PHY features include:
■
Programmable data rates from MCS0–7 in 20 MHz channels.
■
Support for Optional Short GI and Green Field modes in TX and RX.
■
TX and RX LDPC for improved range and power efficiency.
■
All scrambling, encoding, forward error correction, and modulation in the transmit direction and inverse operations in the receive
direction.
■
Support for IEEE 802.11h/k for worldwide operation.
■
Advanced algorithms for low power consumption and enhanced sensitivity, range, and reliability.
■
Algorithms to improve performance in the presence of externally received Bluetooth signals.
■
An automatic gain control scheme for blocking and nonblocking cellular applications.
■
Closed loop transmit power control.
■
Digital RF chip calibration algorithms to handle CMOS RF chip process, voltage, and temperature (PVT) variations.
■
On-the-fly channel frequency and transmit power selection.
■
Per-packet RX antenna diversity.
■
Available per-packet channel quality and signal-strength measurements.
■
Compliance with FCC and other worldwide regulatory requirements.
Figure 9. WLAN PHY Block Diagram
Filters
and
Radio
Comp
Frequency
and Timing
Synch
Carrier Sense,
AGC, and Rx
FSM
Radio
Control
Block
Common
Logic
Block
Filters
and
Radio
Comp
AFE
and
Radio
MAC
Interface
Buffers
OFDM
Demodulate
Viterbi Decoder
Tx FSM
PA Comp
Modulation
and Coding
Frame and
Scramble
FFT/IFFT
CCK/DSSS
Demodulate
Descramble
and Deframe
COEX
Modulate/
Spread
