doc.: IEEE 802.15- Project: IEEE ......doc.: IEEE 802.15- Submission Introduction – WDM (Wave Length Multiplex)WDM (Wave Length

<Nov 2008>

Atsuya Yokoi, Samsung Yokoham Research

Institute

Slide 1

doc.: IEEE 802.15-<08/0743-00>

Submission

Project: IEEE P802.15 Working Group for Wireless Personal Area NProject: IEEE P802.15 Working Group for Wireless Personal Area Networks (etworks (WPANsWPANs))

Submission Title: [Color Multiplex Coding for VLC]

Date Submitted: [07 Nov, 2008]

Source: [Atsuya Yokoi] Company [Samaung Yokohama Research Institute]

Address [2-7, Sugasawa-cho, Tsurumi-ku, Yokohama-shi, Kanagawa, 230-0027 Japan]

Voice:[+81-45-510-4240], FAX: [+81-45-510-3339], E-Mail:[[email protected]]

Re: []

Abstract: [The introduction of the Color Multiplex Coding (CMC) for VLC and its evaluation results.

The BER performances are showed by simulation and experiment.]

Purpose: [Contribution to IEEE 802.15 SG-VLC]

Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for

discussion and is not binding on the contributing individual(s) or organization(s). The material in this

document is subject to change in form and content after further study. The contributor(s) reserve(s) the

right to add, amend or withdraw material contained herein.

Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE

and may be made publicly available by P802.15.

<Nov 2008>


Institute

Slide 2

doc.: IEEE 802.15-<08/0743-00>

Submission

Color Multiplex Codingfor VLC

2008.11.13

Atsuya Yokoi

Samsung Yokohama Research Institute

<Nov 2008>


Institute

Slide 3

doc.: IEEE 802.15-<08/0743-00>

Submission

Contents

• Introduction

• What is CMC?

• Why CMC?

• CMC performance

– Simulation Results

– Experiment Results

• Conclusion

<Nov 2008>


Institute

Slide 4

doc.: IEEE 802.15-<08/0743-00>

Submission

Introduction

– WDM (Wave Length Multiplex)WDM (Wave Length Multiplex)WDM (Wave Length Multiplex)WDM (Wave Length Multiplex) is good modulation scheme for realizing high speed transmissions.

– The wave length and number have to be selected carefully, and those decide devices(LED,PD) and the performance of VLC systems.

– CMC (Color Multiplex Coding) CMC (Color Multiplex Coding) CMC (Color Multiplex Coding) CMC (Color Multiplex Coding) is a new modulation scheme which we propose.

– It doesn’t depend on the wave length and number directly.

– It can be expected better flexibility for VLC system than WDM.

<Nov 2008>


Institute

Slide 5

doc.: IEEE 802.15-<08/0743-00>

Submission

What is CMC?

• Data train is coded in the Data train is coded in the Data train is coded in the Data train is coded in the xyxyxyxy color coordinate. color coordinate. color coordinate. color coordinate. • xyxyxyxy values are transformed into RGB values.values are transformed into RGB values.values are transformed into RGB values.values are transformed into RGB values.• The relation between The relation between The relation between The relation between xyxyxyxy and RGB is showed by and RGB is showed by and RGB is showed by and RGB is showed by following equations according to following equations according to following equations according to following equations according to ““““CIE1931 RGB color CIE1931 RGB color CIE1931 RGB color CIE1931 RGB color spacespacespacespace””””....(R:700nm, G:546.1nm, B:435.8nm)(R:700nm, G:546.1nm, B:435.8nm)(R:700nm, G:546.1nm, B:435.8nm)(R:700nm, G:546.1nm, B:435.8nm)

D/A R

G

B

D/A

D/A

R

G

B

A/D

A/D

A/D

LED PD

xy

to

RGB

Color

Coding

xxxx

yyyy

RGB

to

xy

xxxx

yyyyColor

Decoding

RRRR

GGGG

BBBB

RRRR

GGGG

BBBB

DataDataDataData DataDataDataData

)/(

)/(

5943.50565.0

0601.05907.4

1302.17517.17689.2

ZYXYy

ZYXXx

BGZ

BGRY

BGRX

++=

++=

+=

++=

++=

CIE1931 xy color coordinate

R

01

10

00

11R

B

G

CMC system block diagram

<Nov 2008>


Institute

Slide 6

doc.: IEEE 802.15-<08/0743-00>

Submission

Why CMC?• WDM

• Transmit data is distributed to RGB channels. • The channels are decided by the wave length and number.• Same wave length sources and detectors are required.• System flexibility is lower.

• CMC• Transmit data is allocated in the color coordinate plane.• The channels are decided by the color coordinate.• It doesn’t depend on the wave length and number directly.• System flexibility is higher.

<Nov 2008>


Institute

Slide 7

doc.: IEEE 802.15-<08/0743-00>

Submission

Why CMC?

• Light source spectrum are different among the various devices.Light source spectrum are different among the various devices.Light source spectrum are different among the various devices.Light source spectrum are different among the various devices.• CMC symbols are produced by several light sources according to CMC symbols are produced by several light sources according to CMC symbols are produced by several light sources according to CMC symbols are produced by several light sources according to the color the color the color the color coordinate.coordinate.coordinate.coordinate.• CMC symbolsCMC symbolsCMC symbolsCMC symbols can be produced and reproduced by different light sources.can be produced and reproduced by different light sources.can be produced and reproduced by different light sources.can be produced and reproduced by different light sources.• CMC guarantees the connectivity each device with CMC guarantees the connectivity each device with CMC guarantees the connectivity each device with CMC guarantees the connectivity each device with xyxyxyxy color coordinate.color coordinate.color coordinate.color coordinate.

xy color coordinate

Illumination

Sign board

Mobile

Mobile

R G’’

R’ BG’

R BG

R

01

10

00

11 R

B

G’’

R’

B’

G

G’

B’

R BG

<Nov 2008>


Institute

Slide 8

doc.: IEEE 802.15-<08/0743-00>

Submission

CMC simulation

• Those symbol positions were decided for having same and max disThose symbol positions were decided for having same and max disThose symbol positions were decided for having same and max disThose symbol positions were decided for having same and max distance from adjacent symbols.tance from adjacent symbols.tance from adjacent symbols.tance from adjacent symbols.

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y

Genarated Signal Simbol for CMC

R position

G positionB positionSimbol position

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R position

G positionB position

Simbol position

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R position

G positionB position

Simbol position

4 CMC

(2bits/Symbol)

16 CMC

(4bits/Symbol)64 CMC

(6bits/Symbol)

R

G

B

R

G

B

R

G

B

4CMC：4points Color Multiplex Coding （2bits/symbol)



Symbol position in xy color coordinate for CMC performance evaluation

<Nov 2008>


Institute

Slide 9

doc.: IEEE 802.15-<08/0743-00>

Submission

BER performance with random noiseRandom Noise vs. BER

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

0 5 10 15 20

SNR_RGB [dB]

BER

4CMC

16CMC

64CMC

2WDM

4WDM

4WDM symbol positions （RGB space）

64CMC symbol positions （ｘｙ plane）

2WDM：2level(On-Off)/color WDM （3bits/symbol) with Random Noise

4WDM：4level/color WDM （6bits/symbol) with Random Noise

• 64CMC and 4WDM have same ability for transmitting speed ratio (64CMC and 4WDM have same ability for transmitting speed ratio (64CMC and 4WDM have same ability for transmitting speed ratio (64CMC and 4WDM have same ability for transmitting speed ratio (6bits/symbol).6bits/symbol).6bits/symbol).6bits/symbol).• CMC CMC CMC CMC has 3dB lower BER performance in the random noise environmenthas 3dB lower BER performance in the random noise environmenthas 3dB lower BER performance in the random noise environmenthas 3dB lower BER performance in the random noise environment....

<Nov 2008>


Institute

Slide 10

doc.: IEEE 802.15-<08/0743-00>

Submission

BER performance with common mode noiseRandom Noise & Common mode Noise vs. BER

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

0 5 10 15 20

SNR_RGB [dB]

BER

4WDM_r3

2WDM_r3

4CMC_r3

16CMC_r3

64CMC_r3

64CMC_r3：64points CMC（6bits/symbol) with Random Noise & +3dB Common mode Noise

4WDM_r3：4level/color WDM （6bits/symbol) with Random Noise & +3dB Common mode Noise

• 64CMC and 4WDM have same ability for transmitting speed ration.64CMC and 4WDM have same ability for transmitting speed ration.64CMC and 4WDM have same ability for transmitting speed ration.64CMC and 4WDM have same ability for transmitting speed ration.• CMC CMC CMC CMC has 1.5dB higher BER performance in the common mode noise envirohas 1.5dB higher BER performance in the common mode noise envirohas 1.5dB higher BER performance in the common mode noise envirohas 1.5dB higher BER performance in the common mode noise environmentnmentnmentnment....

<Nov 2008>


Institute

Slide 11

doc.: IEEE 802.15-<08/0743-00>

Submission

CMC Experiment

VLC Test Bed

VLC-Tx

Front-end

VLC-Rx

Front-end

PCPCPCPC

FPGAFPGAFPGAFPGA

DACDACDACDAC

DACDACDACDAC

DACDACDACDAC

Digital boardDigital boardDigital boardDigital board

FPGAFPGAFPGAFPGA

ADCADCADCADC

ADCADCADCADC

ADCADCADCADC

LightLightLightLightProp.Prop.Prop.Prop.

TransmitterTransmitterTransmitterTransmitter

ReceiverReceiverReceiverReceiverDriverDriverDriverDriverVLCVLCVLCVLC

AlgorithmAlgorithmAlgorithmAlgorithm

USB USB USB USB IIII/F/F/F/F

ch1ch1ch1ch1

ch2ch2ch2ch2

chchchch3333

ch1ch1ch1ch1

ch2ch2ch2ch2

chchchch3333

USB USB USB USB IIII/F/F/F/F

USB USB USB USB 2.02.02.02.0

HDDHDDHDDHDD

HardwareHardwareHardwareHardwareSoftwareSoftwareSoftwareSoftware

LED：UVGB1306L

PD：S9702

R

G

B

R

G

B

<Nov 2008>


Institute

Slide 12

doc.: IEEE 802.15-<08/0743-00>

Submission

Experimental Results (2.5MHz/Symbol)

4CMC (5Mbps)

BER < 10-6

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y

Demodulated Signal Simbol for CMC with symbol points (datadem)

R positionG position

B positionSymbol position

Demodulated Signal

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R positionG positionB positionSymbol positionDemodulated Signal

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R position

G positionB positionSymbol positionDemodulated Signal

16CMC (10Mbps)

BER < 10-664CMC (15Mbps)

BER ≒ 10-4

<Nov 2008>


Institute

Slide 13

doc.: IEEE 802.15-<08/0743-00>

Submission

Experimental Results (5MHz/Symbol)

4CMC (10Mbps)

BER < 10-6

16CMC (20Mbps)

BER < 10-664CMC (30Mbps)

BER ≒ 10-3

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R position

G position


Demodulated Signal

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R position

G position


Demodulated Signal

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R position

G position


Demodulated Signal

<Nov 2008>


Institute

Slide 14

doc.: IEEE 802.15-<08/0743-00>

Submission

Experimental Results (10MHz/Symbol)

4CMC (20Mbps)

BER < 10-6

16CMC (40Mbps)

BER ≒ 10-2

64CMC (60Mbps)

BER > 10-1

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R position

G position


Demodulated Signal

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R position

G position


Demodulated Signal

-0.2 0 0.2 0.4 0.6 0.8-0.2

0

0.2

0.4

0.6

0.8

x

y


R position

G position


Demodulated Signal

<Nov 2008>


Institute

Slide 15

doc.: IEEE 802.15-<08/0743-00>

Submission

Experimental Results




BER performance

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

0 10 20 30 40 50 60 70

Bit Rate [Mbps]

BER

64CMC

16CMC

64CMC

4/16CMC4/16CMC

64CMC

<Nov 2008>


Institute

Slide 16

doc.: IEEE 802.15-<08/0743-00>

Submission

Conclusion

� We proposed CMC as a new modulation scheme.

� CMC can provide more flexible VLC system than WDM.

� CMC has better performance than WDM in some case.

� We confirmed 20Mbps transmission on 16CMC.

� We can expect higher transmission speed by using the device (LED, PD) which has wider frequency band.

<Nov 2008>


Institute

Slide 17

doc.: IEEE 802.15-<08/0743-00>

Submission

Thank you for your attention!

Documents

doc.: IEEE 802.15- Project: IEEE ......doc.: IEEE 802.15- Submission Introduction – WDM (Wave Length Multiplex)WDM (Wave Length