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Jin Young Kim, Kwangwoon UniversitySlide 1Slide 1

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

Submission Title: [Cooperative Transmission for LED-ID Network ]Date Submitted: [10 July, 2011]Source: [Jin Young Kim, Yoon Hyun Kim, In Hwan Park, Jaesang Cha, Kyesan Lee, and Yeong Min

Jang] [Kwangwoon University, Seoul National University of Technology, Kyunghee University,

Kookmin University]

Address [Kwangwoon University, Seoul, Korea]Voice:[82-10-5355-4825], FAX: [82-2-913-5006], E-Mail:[jinyoung@kw.ac.kr]

Re: []

Abstract: [Some Considerations for Draft VLC Specification]

Purpose: [Contribution to IEEE 802.15.7 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.

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Slide 2

Contents

• Introduction

- Shadow region problem in LED-ID Network

• Cooperative Transmission - Concept & Motivation

- Performance of Cooperative Transmission

• Conclusion

Jin Young Kim, Kwangwoon University

July. 2011

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Problem of LED-ID Network

Jin Young Kim, Kwangwoon UniversitySlide 3

July. 2011

- If Reader 2 is out of tag’s network, it can not receive tag’s signal

- Region of network for LED-ID is limited

- Shadow region → decrease coverage → lower capacity

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Discussion• Current draft VLC specification bases on IEEE 802.15.4

• Current draft VLC specification may consider cooperative transmission for problem of LED-ID Network.

Jin Young Kim, Kwangwoon UniversitySlide 4

July. 2011

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Slide 5 Jin Young Kim, Kwangwoon University

Concept & Motivation of CooperativeJuly. 2011

• Cooperative communication in wireless networks.– They allow single-antenna mobiles to reap some of the benefits of MIMO

systems.

– Transmit diversity (mitigate fading) and coding gain (lower BER).

• In wireless cooperative networks, the wireless agents (users) may increase their effective quality of service (BER, Outage probability,…) via cooperation.

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• Advantages

Higher spatial diversity

Higher throughput

Lower delay

Reduced interference

Lower transmitted power

Adaptability to network conditions

Cooperative Transmission

Jin Young Kim, Kwangwoon University

July. 2011

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Slide 7

Types of Cooperative Transmission

Jin Young Kim, Kwangwoon University

July. 2011

• Requirements for application– AF and multihop : existing system (repeater)

– CC : change at both source and destination nodes

– Network coding : changes at higher layers

– CF : changes at destination node and extra CSI (Channel state information)

Relay

Source Destination

Amplify – and – Forward (AF)

Detect – and – Forward (DF)

Cooperative Coding (CC)

Compress – and - Forward (CF)

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Slide 8

Amplify-and-Forward (AF)

Jin Young Kim, Kwangwoon University

July. 2011

• How it works

– Amplify and retransmit

– Decision is made at the

Reader 2

• Two independently faded versions of same signal, leading to diversity

• Inter-user channel coefficients are assumed to be known at the base station to do the optimal decoding

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Jin Young Kim, Kwangwoon UniversitySlide 9

July. 2011

- We propose an expanding coverage method through cooperative

transmission for network.

-Using cooperative relay, Reader 2 can receive Tag’s signal

→ “Increasing” coverage, “Better” reliability

→ Boosting network capacity

Cooperative Transmission for LED-ID systems

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Cooperative Transmission Model

Jin Young Kim, Kwangwoon University

July. 2011

Received signal at the Reader 2;

2121

211

21

211

211

211

2 22 RRRR

RSSRSR

RRRRSR

RSSRSR

RRSRR nnh

nnEh

Exhh

nnEh

EEy

noiseadditivenn

responseimpulsechannelhh

energyontransmissiEE

signalreceivedy

signaldtransmittex

RR

RRSR

RRSR

R

,

,

,

21

211

211

2

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Slide 11 Jin Young Kim, Kwangwoon University

July. 2011

Performance of Cooperative Transmission

• BER performance of cooperative transmission for LED-ID network

• Compared according to distance between Tag and Reader

• Using amplify-and-forward(AF) cooperative method

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Conclusion• We propose improved expanding LED-ID network coverage.

• Proposed Cooperative Transmission in cooperative network for LED-ID systems - Better reliability - High SNR - Increase channel capacity

Jin Young Kim, Kwangwoon University

July. 2011