Doc.: IEEE 802.11-01/618 Submission November 2001 Srikanth Gummadi, TI High performance encoders:...
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Novembe r 2001 Srikanth Gummadi, TI doc.: IEEE 802.11- 01/618 Submission High performance encoders: What must be added to an IEEE 802.11b transmitter Srikanth Gummadi, M.S., Sean Coffey, Ph.D. & Chris Heegard, Ph.D. Texas Instruments 141 Stony Circle, Suite 130 Santa Rosa California 95401 (707) 521-3060, [email protected]
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doc.: IEEE /618r0 Submission November 2001 Srikanth Gummadi, TI CCK-OFDM at the TX Data Scrambler BCC Encoder (k = 7) Puncture Interleave Constellation Mapping 64-pt Inverse FFT Uncoded Information Bits Cyclic Extension (80 samples) To RF subsection Depends on data rate BPSK, QPSK, 16 QAM, 64QAM
Transcript of Doc.: IEEE 802.11-01/618 Submission November 2001 Srikanth Gummadi, TI High performance encoders:...
November 2001
Srikanth Gummadi, TI
doc.: IEEE 802.11-01/618
Submission
High performance encoders:What must be added to an IEEE
802.11b transmitterSrikanth Gummadi, M.S.,
Sean Coffey, Ph.D. & Chris Heegard, Ph.D.
Texas Instruments 141 Stony Circle, Suite 130
Santa Rosa California 95401(707) 521-3060,[email protected]
November 2001
Srikanth Gummadi, TI
doc.: IEEE 802.11-01/618r0
Submission
A submitted compromise• Summary:
– Both CCK/OFDM and PBCC transmitters are mandatory– Must implement one of either CCK/OFDM or PBCC receiver
• or both– Systems with either receiver can interoperate
• With 11b networks via CCK• Within and between each other via new high rate modes
• Details: IEEE 802.11-01/446r0
CCK/OFDM Receiver
PBCC Receiver
24 Mbps, CCK/OFDM Packet
22 Mbps, PBCC Packet
November 2001
Srikanth Gummadi, TI
doc.: IEEE 802.11-01/618r0
Submission
CCK-OFDM at the TX
Data Scrambler
BCCEncoder(k = 7)
Puncture InterleaveConstellation
Mapping
64-ptInverse
FFT
UncodedInformation
Bits
CyclicExtension
(80 samples)
To RF subsection
Depends on data
rate
BPSK, QPSK, 16 QAM, 64QAM
November 2001
Srikanth Gummadi, TI
doc.: IEEE 802.11-01/618r0
Submission
PBCC at the TX
Data Scrambler
BCCEncoder(k = 7/9)
Cover Sequence
ConstellationMapping
(bits to symbols)Pulse
Shaping
To RF subsection
BPSK, QPSK, 8-PSK
UncodedInformation
Bits
November 2001
Srikanth Gummadi, TI
doc.: IEEE 802.11-01/618r0
Submission
Implementation of both TX
Data Scrambler
BCCEncoder(k = 7)
Puncture InterleaveConstellation
Mapping(bits to symbols)
64-ptInverse
FFT
UncodedInformation
Bits
CyclicExtension
to80 samples
To RF subsection
(k = 7/9)
Cover Sequence
PulseShaping
To RF subsection
8-PSK
November 2001
Srikanth Gummadi, TI
doc.: IEEE 802.11-01/618r0
Submission
Implementation of both TX Approximate Relative Sizes
CyclicExtension
to80 samples(k = 7/9)
64-ptInverse
FFTTo RF
subsection
November 2001
Srikanth Gummadi, TI
doc.: IEEE 802.11-01/618r0
Submission
Summary• Proponents of CCK-OFDM
– PBCC at the TX comes for “free”– No known implementation of CCK-OFDM– No new clocking
• Proponents of PBCC– Need to incorporate the complex CCK-OFDM TX– Change to the existing chip is required– Complex clocking required (11 MHz -> 20 MHz)
• This potential consensus solution will provide the opportunity to allow the industry to move forward rapidly with a known direction
