doc.: IEEE /618 Submission November 2001 Srikanth Gummadi, TI High performance encoders: What must be added to an IEEE b transmitter Srikanth Gummadi, M.S., Sean Coffey, Ph.D. & Chris Heegard, Ph.D. Texas Instruments 141 Stony Circle, Suite 130 Santa Rosa California (707) ,

doc.: IEEE /618r0 Submission November 2001 Srikanth Gummadi, TI 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 /446r0

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

doc.: IEEE /618r0 Submission November 2001 Srikanth Gummadi, TI PBCC at the TX Data Scrambler BCC Encoder (k = 7/9) Cover Sequence Constellation Mapping (bits to symbols) Pulse Shaping To RF subsection BPSK, QPSK, 8-PSK Uncoded Information Bits

doc.: IEEE /618r0 Submission November 2001 Srikanth Gummadi, TI Implementation of both TX Data Scrambler BCC Encoder (k = 7) Puncture Interleave Constellation Mapping (bits to symbols) 64-pt Inverse FFT Uncoded Information Bits Cyclic Extension to 80 samples To RF subsection (k = 7/9) Cover Sequence Pulse Shaping To RF subsection 8-PSK

doc.: IEEE /618r0 Submission November 2001 Srikanth Gummadi, TI Implementation of both TX Approximate Relative Sizes Cyclic Extension to 80 samples (k = 7/9) 64-pt Inverse FFT To RF subsection

doc.: IEEE /618r0 Submission November 2001 Srikanth Gummadi, TI 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