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Transcript of 11 03 0283 00 Htsg Signaling for Adaptive Modulation
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8/22/2019 11 03 0283 00 Htsg Signaling for Adaptive Modulation
1/12
doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 1
Signaling for AdaptiveModulation
byDr. Gnter Kleindl
Siemens AG
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 2
Motivation and Requirements
Adaptive modulation is one method to improve
the throughput and/or range
Adaptive modulation requires signaling
Easy implementation and compatibility to IEEE 802.11a/g
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 3
Conventional Modulation for
OFDM-SubcarriersSNR(f)
f
QPSK 3/4QPSK 1/2BPSK 3/4
16 QAM 1/216 QAM 3/4
64 QAM 3/4
SNRAverage
shifting
ofg
rid
All subcarriers get the same modulation alphabet
64 QAM 2/3
BPSK 1/2
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 4
Adaptive Modulation for
OFDM-Subcarriers
Bundles of adjacent subcarriers
get individual modulation alphabets
SNR(f)
8-PSK4-PSK2-PSK
unused
16-QAM
32-QAM64-QAM
128-QAM
256-QAM
m=3
SNRAverage
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 5
How to implement ?
Source
DestinationCTS ACK
RTS Data
A small extension in the RTS / CTS frames is a solution
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 6
RTS Frame Format
Frame
ControlDuration RA TA FCS
Protocol
VersionType Subtype Other Bits
Take an unused bit combination in the Subtype fieldto signal in the RTS that a terminal is able to transmit
according to the bit loading feature,
e.g. Subtype = 0011
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 7
CTS Frame Format
Frame
ControlDuration RA
Bit Loading
TableFCS
The destination terminal measures the RTS
subcarriers and answers with a bit loading table for
adaptive modulation in the CTS frame.
The source modulates the data frame according to
the bit loading table.
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 8
Example of a Bit Loading Table
Number 8 possible PHY-modes and select one for
each of the 16 bundles, i.e. 3 bit x 16 = 48 bits = 6 bytes.
Transport these bytes in the CTS frame.
000 Nil
001 BPSK
010 QPSK
011 8 PSK
100 16 QAM
101 32 QAM
110 64 QAM
111 128 QAM
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 9
Range Enhancement
0
20
40
60
80
Rangeenhancement/
%
6 9 12 18 27 36 54
Data Rate / Mbps
Adaptive modulation can significantly improve
the range
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 10
Other Companys ResultsDoc.#: 11-02-232r0-WNG from Aware
Adaptive modulation can significantly improve
the throughput
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 11
Conclusions
Adaptive modulation is one method to improve
the throughput and/or range
The available RTS/CTS signaling can easily be extended
for adaptive modulation and further techniques like
multiple transmit antennas
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doc.: IEEE 802.11-03/283r0
Submission
May 2003
G. Kleindl / SiemensSlide 12
Thank you for
your attention !
