Doc.: IEEE 802.11-08/0361r0 Submission Hyun Seo Oh, ETRI July 2008 Slide 1 Radio Transmission Technology for V2V/V2I Applications Date: 2008-07-17 Authors:

July 2008

Slide 1

doc.: IEEE 802.11-08/0361r0

Submission Hyun Seo Oh, ETRISlide 1

Radio Transmission Technology for V2V/V2I Applications

Date: 2008-07-17

Name Affiliations Address Phone email Hyun Seo Oh ETRI 161 Gajeong-dong,

Yuseong-gu, Daejeon, Korea

+82-42-860-5659

[email protected]

Sang Woo Lee ETRI 161 Gajeong-dong, Yuseong-gu, Daejeon, Korea

+82-42-860-5254

[email protected]

Sang In Kim ETRI 161 Gajeong-dong, Yuseong-gu, Daejeon, Korea

+82-42-860- 1346

[email protected]

Authors:

July 2008

Slide 2

doc.: IEEE 802.11-08/0361r0

Submission Hyun Seo Oh, ETRI

contents

V2V/V2I ApplicationsV2V/V2I Applications1111

Service RequirementsService Requirements2222

Performance SimulationPerformance Simulation4444

Proposed TechnologiesProposed Technologies3333

SummarySummary5555

July 2008

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doc.: IEEE 802.11-08/0361r0


V2V Communication : Vehicle Multi-hop Networking for Vehicle Safety

V2I Communication : Bi-directional Packet Communication for ITS/Telematics

Accident

GPS

Emergency

Message

Warning Message

Cellular/WiBro

Probe Data

TSP Server

Internet

RSE RSE

Traffic Information

V2V V2I

Hopping

Warning Message

V2V/V2I Applications

July 2008

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doc.: IEEE 802.11-08/0361r0


V2V Service Use Case

Warning Message Broadcasting

Detect accident or road status in real time & broadcast warning message

to the following vehicle by using vehicle to vehicle multi-hop communication

Vehicle 1

Vehicle 2

Vehicle 3

②

①

③

July 2008

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doc.: IEEE 802.11-08/0361r0


Road/TrafficInformation

Probe data collection

BackboneNetwork

Traffic Information

Center

Probe Vehicle

Traffic

Probe data collection/Traffic information RSE collects probe data from the vehicle periodically

and provides traffic and road status information to vehicles

Road/TrafficInformation

V2I Service Use Case

July 2008

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RSUAntenna

RoadsideHost

Processor and

Backhaul Equipment

Inside

Equipment Cabinet

Traffic Management or Other Center

Internet or

Private Network

Traffic Management

Center Server/Network Interface

Two-way RF

ITS/Telematics

Application

Roadside Unit (RSU)

Frequency (GHz)

Service Requirements

Basic Requirements • Communication : Broadcasting, Unicasting• Mobility : Max. 200 km/h• Packet Latency : < 100 msec• Long packet transmission : ~1kbytes• Networking : V2I or VANET

July 2008

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doc.: IEEE 802.11-08/0361r0


Preamble Payload MidamblePayload Payload Payload Midamble Payload Payload

Channelestimation

Equalizer

ChannelEstimation& Update

Equalizer

ChannelEstimation& Update

Equalizer

N symbol

∙∙∙ ∙∙∙ ∙∙∙

Proposed Technologies

Mid-amble based Channel Estimation in Vehicle Mobility

. Conventional : Preamble or Pilot Sub-carriers based Initial Channel Estimation

- Problem : Performance degraded for long packet reception because it provides only

initial time and channel phase acquisition

. New : Mid-amble based Channel Estimation and Tracking

- Benefits : Good performance for long packet reception because it provides initial and

continuous time and channel phase acquisition

Mid-amble based Channel Estimation in Vehicle Mobility

. Conventional : Preamble or Pilot Sub-carriers based Initial Channel Estimation

- Problem : Performance degraded for long packet reception because it provides only

initial time and channel phase acquisition

. New : Mid-amble based Channel Estimation and Tracking

- Benefits : Good performance for long packet reception because it provides initial and

continuous time and channel phase acquisition

July 2008

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doc.: IEEE 802.11-08/0361r0


Controlslot

serviceslot#n

frame

Beaconslot

Serviceslot#1

Controlslot

serviceslot#n

frame

Beaconslot

Serviceslot#1

time

DATA ACK RTS CTS DATA ACKtime

RTS CTS

CSMA/CA-TDMA combined MAC with priority control • Conventional : CSMA

- Problem : Throughput degradation for the increased number of users

• New : CSMA/CA-TDMA combined MAC

- Benefits : Better throughput by time slot scheduling, useful for VANET and V2I

CSMA/CA-TDMA combined MAC with priority control • Conventional : CSMA

- Problem : Throughput degradation for the increased number of users

• New : CSMA/CA-TDMA combined MAC

- Benefits : Better throughput by time slot scheduling, useful for VANET and V2I

Proposed Technologies

July 2008

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Performance Simulation

Radio Link Simulation

. Transceiver model : IEEE 802.11p with Mid-amble insertion

. Radio Channel Model : TDL filter model, which was proposed by GIT, USA

. Comparative analysis : Performance of Preamble based or Mid-amble based

channel estimation

Radio Link Simulation

. Transceiver model : IEEE 802.11p with Mid-amble insertion

. Radio Channel Model : TDL filter model, which was proposed by GIT, USA

. Comparative analysis : Performance of Preamble based or Mid-amble based

channel estimation

Training symbol(short & long) generation Mapper(BPSK,QPSK,

16QAM,64QAM)

PilotInsertion

IFFTGI

AddSymbol

Wave Shaping Channel

+AWGN

Data

ViterbiDecoder

De-Puncturing

De-Interleaver

De-Mapper

Equalizer FFT FrequencyOffset

Recovery

GIRemove

SymbolSync.

SignalPower

Detection

Channel Estimation

ConvolutionalEncoder

Puncturing(1/2,2/3,3/4)

Interleaver

Data

Synchronization

July 2008

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Packet Length Analysis of Preamble based Estimation

. If packet length is less than 40 bytes, its performance is good.

However, its performance will be worse as the packet length is increasing

. Long sized packet to be order of 1kbytes : needs new technology for V2I applications

Packet Length Analysis of Preamble based Estimation

. If packet length is less than 40 bytes, its performance is good.

However, its performance will be worse as the packet length is increasing

. Long sized packet to be order of 1kbytes : needs new technology for V2I applications

40 60 80 100 120 140 160 180 20010

-4

10-3

10-2

10-1

100

Packet Length

BE

R

3Mbps(BPSK, R1/2)6Mbps(QPSK, R1/2)12Mbps(16QAM, R1/2)


July 2008

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doc.: IEEE 802.11-08/0361r0


Radio Link Simulation for 200 bytes packet

. Fading Loss : approximated 20 dB if channel estimation is perfect

. Mid-amble channel estimation performance for BPSK/16QAM modulation :

approaches performance of ideal channel estimation even though it is impacted by

radio channel models

Radio Link Simulation for 200 bytes packet

. Fading Loss : approximated 20 dB if channel estimation is perfect

. Mid-amble channel estimation performance for BPSK/16QAM modulation :

approaches performance of ideal channel estimation even though it is impacted by

radio channel models

-5 0 5 10 15 20 25 30

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

12Mbps - 16QAM, R1/2

Eb/No[dB]

BE

R

Midamble CH1Preamble CH1

Perfect CH1

Midamble CH5

Preamble CH5Perfect CH5

Midamble CH7

Preamble CH7

Perfect CH7AWGN

-5 0 5 10 15 20 25 30

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

3Mbps - BPSK, R1/2

Eb/No[dB]

BE

R


Perfect CH1

Midamble CH5


Midamble CH7

Preamble CH7

Perfect CH7AWGN


July 2008

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Radio Link Simulation for 1 Kbytes packet. Mid-amble channel estimation for BPSK/16QAM : approaches performance of ideal

channel estimation, uniform performance irrespective of modulation level

Radio Link Simulation for 1 Kbytes packet. Mid-amble channel estimation for BPSK/16QAM : approaches performance of ideal

channel estimation, uniform performance irrespective of modulation level

-5 0 5 10 15 20 25 3010

-7

10-6

10-5

10-4

10-3

10-2

10-1

100

3Mbps: BPSK, R1/2

Eb/No[dB]

BE

R


Perfect CH1

Midamble CH5


Midamble CH7

Preamble CH7

Perfect CH7AWGN

-5 0 5 10 15 20 25 3010

-7

10-6

10-5

10-4

10-3

10-2

10-1

100

12Mbps: 16QAM, R1/2

Eb/No[dB]

BE

R


Perfect CH1

Midamble CH5


Midamble CH7

Preamble CH7

Perfect CH7AWGN


July 2008

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doc.: IEEE 802.11-08/0361r0


MAC simulation

• PHY : 802.11a OFDM, 6Mbps fixed

• MAC : 802.11 DCF, CSMA/CA-TDMA combined MAC

• Number of slot : 4 slots for CSMA/CA-TDMA combined MAC

• Application : CBR Traffic (Unicast, Broadcast)

• Simulation tool : Qualnet 4.0 version

MAC simulation

• PHY : 802.11a OFDM, 6Mbps fixed

• MAC : 802.11 DCF, CSMA/CA-TDMA combined MAC

• Number of slot : 4 slots for CSMA/CA-TDMA combined MAC

• Application : CBR Traffic (Unicast, Broadcast)

• Simulation tool : Qualnet 4.0 version

5, 10, 15, 20 unicast flows 10, 20. 30, 40 broadcast flows


July 2008

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doc.: IEEE 802.11-08/0361r0


Unicast Scenario• Unicast CBR Flows : 5~20• Performance parameter : Throughput & Delay

Unicast Scenario• Unicast CBR Flows : 5~20• Performance parameter : Throughput & Delay

Number of flows

Thro

ughput

(bps)

Number of flows

Dela

y

[sec]


July 2008

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doc.: IEEE 802.11-08/0361r0


Unicast Scenario• Unicast CBR Flows : 5~20• Performance parameter : No of Retransmission (RTS)

Unicast Scenario• Unicast CBR Flows : 5~20• Performance parameter : No of Retransmission (RTS)

Number of flows

No. o

f re

transm

ission

No. o

f re

transm

ission

Node ID Information


July 2008

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doc.: IEEE 802.11-08/0361r0


Broadcast scenario• Broadcast CBR Flows : 10 ~40• Performance parameter : Throughput & Delay

Broadcast scenario• Broadcast CBR Flows : 10 ~40• Performance parameter : Throughput & Delay

Number of flows

Thro

ughput

(bps)

Number of flows

Dela

y

(sec)


July 2008

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doc.: IEEE 802.11-08/0361r0


• Vehicle Services will be categorized into

– V2V based Vehicle Safety Service : Intersection Collision Avoidance

– V2I bases Convergence Service : ITS/Telematics/USN Convergence Service

• V2V/V2I Communication has basic requirements– High Mobility : 200 Km/h

– Low Latency : <100 msec

– Long Packet Transmission : ~ 1kbytes

– Networking : VANET or V2I

• Propose New Challenging Technologies

- Mid-amble based Channel estimation for long packet

- CSMA/CA-TDMA combined MAC for service priority

Summary

Documents

Doc.: IEEE 802.11-08/0361r0 Submission Hyun Seo Oh, ETRI July 2008 Slide 1 Radio Transmission Technology for V2V/V2I Applications Date: 2008-07-17 Authors: