BCM43455 Preliminary Data Sheet
IEEE 802.11ac PHY
The PHY has been designed to work in the presence of interference, radio nonlinearity, and various other
impairments. It incorporates optimized implementations of the filters, FFT and Viterbi decoder algorithms.
Efficient algorithms have been designed to achieve maximum throughput and reliability, including algorithms for
carrier sense/rejection, frequency/phase/timing acquisition and tracking, channel estimation and tracking. The
PHY receiver also contains a robust IEEE 802.11b demodulator. The PHY carrier sense has been tuned to
provide high throughput for IEEE 802.11g/11b hybrid networks with Bluetooth coexistence. It has also been
designed for shared single antenna systems between WL and BT to support simultaneous RX-RX.
The key PHY features include:
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Programmable data rates from MCS0–MCS9 in 20, 40, and 80 MHz channels, as specified in
IEEE 802.11ac.
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Supports 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.
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Supports IEEE 802.11h/k for worldwide operation.
Advanced algorithms for low power, enhanced sensitivity, range, and reliability.
Algorithms to improve performance in presence of Bluetooth.
Automatic gain control scheme for blocking and non blocking application scenario for cellular applications.
Closed loop transmit power control.
Digital RF chip calibration algorithms to handle CMOS RF chip non-idealities.
On-the-fly channel frequency and transmit power selection.
Supports per-packet RX antenna diversity.
Available per-packet channel quality and signal strength measurements.
Designed to meet FCC and other worldwide regulatory requirements.
Figure 29: WLAN PHY Block Diagram
CCK/DSSS
Demodulate
Filters
and
Radio
Comp
Frequency
and Timing
Synch
Descramble
and Deframe
OFDM
Demodulate
Viterbi Decoder
Carrier Sense,
AGC, and Rx
FSM
Radio
Control
Block
Buffers
FFT/IFFT
MAC
Interface
AFE
and
Radio
TX
FSM
Modulation
and Coding
Common
Logic
Block
Frame and
Scramble
Filters
and
Radio
Comp
Modulate/
Spread
PA Comp
COEX
Broadcom®
November 5, 2015 • 43455-DS109-R
Page 77
BROADCOM CONFIDENTIAL
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