doc.: IEEE 802.11-15/0096r0

Submission

January 2015

Daniel Schneider, SonySlide 1

Non-Uniform Constellations for Higher Order QAMs

Date: 2015/01/12

Authors:

Name Affiliations Address Phone email Daniel Schneider Sony

Deutschland GmbH

Hedelfingestr. 61, 70327 Stuttgart, Germany

daniel.schneider@eu.sony.com

doc.: IEEE 802.11-15/0096r0

Submission

Motivation (1/2)

• Higher order QAMs discussed in e.g. [1]-[2] as potential technology for next-generation 60GHz– OFDM: 128-QAM, 256-QAM (up to 64-QAM in ad)– SC: 64-QAM (up to 16-QAM in ad)

• Non-uniform constellations (NUCs) provide increased performance compared to uniform constellations (UCs)– Optimum location of constellation points– Robust and weak bits carry

optimum amount of information

January 2015

Slide 2 Daniel Schneider, Sony

doc.: IEEE 802.11-15/0096r0

Submission

Motivation (2/2)

• Introduced lately in several broadcast standards– DVB-NGH [3], DVB/S2x [4]– Theoretical shaping gain up to 1.5dB

• Moderate complexity increase– Change of QAM (de)mapper

January 2015

Slide 3 Daniel Schneider, Sony

doc.: IEEE 802.11-15/0096r0

Submission

NUC: 1-D vs 2D

• 1-D NUC– I/Q symmetry – 1-D demapping as for uniform

constellations (UC), i.e. samedemapping complexity as for regular QAMs

• 2-D NUC– Symmetric quadrants– Higher gain compared to 1-D NUC– 2-D demapping required

January 2015

Slide 4

-1 -0.5 0 0.5 1

-1

-0.5

0

0.5

1

Re{xl}

Im{xl}

1D 16NUC for 3dB1-D NUC: 16-QAM

2-D NUC: 16-QAM

Daniel Schneider, Sony

doc.: IEEE 802.11-15/0096r0

Submission Eisuke Sakai, Sony Corporation

NUC Example for different SNR Conditions

January 2015

Slide 5

-10 -5 0 5 10 15 200

0.2

0.4

0.6

0.8

18NUC optimized at 0 dB

SNR [dB]

bitw

ise B

ICM

capacity f

or

AW

GN

channel

bit 0

bit 1bit 2

-1 -0.5 0 0.5 1

-1

-0.5

0

0.5

1

Re{xl}

Im{

x l}

8NUC for SNR = 0 dB

100 000110 010

101 001011111 -10 -5 0 5 10 15 200

0.2

0.4

0.6

0.8

1

SNR [dB]

bitw

ise B

ICM

capacity f

or

AW

GN

channel

bit 0

bit 1

bit 2

weak bits

robustbits

0.0000+0.4859+0.4859= 0.97190.1282+0.3973+0.3973 = 0.9229

8PSK reference

weak bits

robustbits

2 over-lapping points

8NUC for low SNR

Interpretation: weak bits carry no information, 2 most robust bits with maximum distance

8NUC for high SNR

-1 0 1

-1.5

-1

-0.5

0

0.5

1

1.5

Re{xl}

Im{

x l}

8ary ideal hexagonal lattice

111010

001

100000

110

101

011

-10 -5 0 5 10 15 200

0.2

0.4

0.6

0.8

1

SNR [dB]

bitw

ise B

ICM

capacity f

or

AW

GN

channel

bit 0

bit 1

bit 2

robustbits

0.9393+0.9697+0.9697 =2.8787

8PAM reference

weak bits

-10 -5 0 5 10 15 200

0.2

0.4

0.6

0.8

1

SNR [dB]

bitw

ise B

ICM

capacity f

or

AW

GN

channel

8ary hexagonal lattice

bit 0

bit 1

bit 2

weak bits

robustbits

0.9749+0.9749+0.9779 =2.9276

Interpretation: hexagonal lattice = „dense packing“ , maximize minimum Euclidean distance

doc.: IEEE 802.11-15/0096r0

Submission

• Replacement of original uniform constellations by NUC• OFDM, MCSs: 18-24• Additionally: 128- and 256-QAM• Message Length: 1000bytes• Channel AWGN

– AWGN (channel is very closeto AWGN in the LOS case)

• Gain evaluated compared to UCat FER=10-2

• 1D and 2D NUC

Initial Simulations: Parameters

January 2015

Slide 6

MCS index modulation bit/symbol coderate18 16-QAM 4 1/219 16-QAM 4 5/820 16-QAM 4 3/421 16-QAM 4 13/1622 64-QAM 6 5/823 64-QAM 6 3/424 64-QAM 6 13/16

128-QAM 7 1/2128-QAM 7 5/8128-QAM 7 3/4128-QAM 7 13/16256-QAM 8 1/2256-QAM 8 5/8256-QAM 8 3/4256-QAM 8 13/16

Daniel Schneider, Sony

doc.: IEEE 802.11-15/0096r0

Submission

1/2 5/8 3/4 13/16 5/8 3/4 13/16 1/2 5/8 3/4 13/16 1/2 5/8 3/4 13/160

0.2

0.4

0.6

0.8

1

1.2

code rate

wa

terf

all

SN

R g

ain

[dB

] @F

ER

=1

e-2

gain compared to UC, OFDM AD, AWGN

1D NUC

2D NUC

• Up to 0.8dB gain of NUC compared to regular QAM

Initial Simulations: ResultsChannel: AWGN

January 2015

Slide 7

16-QAM

64-QAM

256-QAM128-QAM*802.11ad

* Only 2D-NUCsimulated Daniel Schneider, Sony

doc.: IEEE 802.11-15/0096r0

Submission

Conclusions

• Significant gain of NUC compared to UC– Gain up to 0.8dB for 128-QAM and 0.7dB for 256-QAM

• Moderate complexity increase– Isolated change of QAM mapper and demapper– Same demapper complexity as for uniform constellations for 1-D NUCs– 2-D demapping required for 2-D NUCs

January 2015

Slide 8 Daniel Schneider, Sony

doc.: IEEE 802.11-15/0096r0

Submission

References

1. Alecsander Eitan, Qualcomm, 11-14-1378-00-ng60 PHY rate for NG60

2. Alecsander Eitan, Qualcomm et al, 11-14-0652-00-0wng-wng Next Generation 802.11ad

3. Next Generation broadcasting system to Handheld, physical layer specification (DVB-NGH), DVB BlueBook A160, 2012

4. DVB-S2X BlueBook A83-2 / EN302307-2

January 2015

Slide 9 Daniel Schneider, Sony

doc.: IEEE 802.11-15/0096r0

Submission

BACKUP

January 2015

Slide 10 Daniel Schneider, Sony