Simulation Results of Coding Diversity Soft Handoff Design

Soon-Yil Kwon, Young-Woo Yun, Young-Jo Lee, Ki-Jun KimLGIC

3GPP2 TSG-C WG 3 Physical LayerApril. 26, 2000

C30-20000426-006

Presentation Outline

• Introduction and Motivation

• Softer Handoff Scheme

• The proposed Softer Handoff System Model

• Simulation Configuration

• Simulation Results

• Conclusions

2SH31599.ppt

Introduction and Motivation

• Recent Measurements of an operating IS-95 CDMA Cellular System indicate that an average of 30% to 50% call period is in soft-handoff process

• System Reliability during handoff becomes one of the major system performance parameters

• We Propose “Novel Soft Handoff Method” to achieve a kind of coding diversity gain as well as conventional diversity gain

• Coding diversity can be achieved by assigning different coding and puncturing to each base station in soft-handoff mode

• First, the gain in the case of turbo codes will be demonstrated

• This gain is also achievable for convolutional codes

3SH31599.ppt

Softer Handoff Scheme

• System Model for the Cellular Handoff

The proposed Softer Handoff System Model

• Transmitter structure for the turbo coding of cdma2000

ConstituteEncoder 1, 2

Switch

Symbol Puncture

andRepetition

Modulationand

Spreading (1)

'1

'0

'10 ,,,,, YYXYYX '

1'0

'10 ,,,,, YYXYYX

Channel bitsdk

Base Station A

Base Station B

Turbo Encoder

ConstituteEncoder 1, 2

Switch

Symbol Puncture

andRepetition

'1

'0

'10 ,,,,, YYXYYX

Turbo Encoder

10'1

'0

' ,,,,, YYXYYX

Modulationand

Spreading (1)

(1) Inc ludes Symbo l repetition, Symbol puncture, Block interleaving, Modulation and Spreading

The proposed Softer Handoff System Model

• Receiver structure for turbo coding of cdma2000

DigitalFinger 3

DigitalFinger 2

DigitalFinger 1

RF CircuitAnalog

Receiver

DigitalFinger 4

Searcher

Deinterleaver

Deinterleaver

Deinterleaver

Deinterleaver

ControlProcessor

Switch

Switch

Switch

Switch

Divercity Combiner

Decoder

Signal from Base Station A

Signal from Base Station B

Simulation Configuration

• Radio configuration: RC3(19200bps, Turbo coding), RC4(19200bps, Turbo coding), RC5(28800bps, Turbo coding),

• Carrier frequency: 2GHz

• Channel model: 1 path Rayleigh fading channel or Equal energy 2 path Rayleigh fading

• The number of BS: 2

• PC step/ PC error/ PC Delay: 1 dB / 0 %/1 PCG

• MIN/MAX of fraction power allocation: -40/-3 dB

• Perfect channel estimation

• Perfect SIR estimation for Power control

7SH31599.ppt

Simulation Configuration (Cont’d)

• Definitions

Ec : Average energy per PN chip for the traffic channel

Ior1: The total transmitted power spectral density from base station 1

Ior2: The total transmitted power spectral density from base station 2

Îor1: The received power spectral density from base station 1

Îor2: The received power spectral density from base station 2

Ioc: The power spectral density of a band-limited white noise source.

• Legend CUR(xdB): Normal softer Handoff case with (Îor1 + Îor2 ) / Ioc = xdB

PRO(xdB): Proposed softer Handoff case with (Îor1 + Îor2 ) / Ioc = xdB

8SH31599.ppt

RC3 Result (1 path Rayleigh Fading)

• Velocity 3km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 17 - 16 - 15 - 14 - 13 - 12 - 11 - 10 - 9

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC3 Result (1 path Rayleigh Fading)

• Velocity 30km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 18 - 17 - 16 - 15 - 14 - 13 - 12 - 11 - 10

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC3 Result (1 path Rayleigh Fading)

• Velocity 100km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 18 - 17 - 16 - 15 - 14 - 13 - 12 - 11

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC3 Result (2 path Rayleigh Fading)

• Velocity 3km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 17 - 16 - 15 - 14 - 13 - 12 - 11

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC3 Result (2 path Rayleigh Fading)

• Velocity 30km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 17 - 16 - 15 - 14 - 13 - 12 - 11

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC3 Result (2 path Rayleigh Fading)

• Velocity 100km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 18 - 17 - 16 - 15 - 14 - 13 - 12 - 11

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC4 Result (1 path Rayleigh Fading)

• Velocity 3km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 16 - 15 - 14 - 13 - 12 - 11 - 10 - 9

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC4 Result (1 path Rayleigh Fading)

• Velocity 30km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 17 - 16 - 15 - 14 - 13 - 12 - 11 - 10 - 9

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC4 Result (1 path Rayleigh Fading)

• Velocity 100km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 17 - 16 - 15 - 14 - 13 - 12 - 11 - 10 - 9

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC4 Result (2 path Rayleigh Fading)

• Velocity 3km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 16 - 15 - 14 - 13 - 12 - 11 - 10

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC4 Result (2 path Rayleigh Fading)

• Velocity 30km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 16 - 15 - 14 - 13 - 12 - 11 - 10

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC4 Result (2 path Rayleigh Fading)

• Velocity 100km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 16 - 15 - 14 - 13 - 12 - 11 - 10

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC5 Result (1 path Rayleigh Fading)

• Velocity 3km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 15 - 14 - 13 - 12 - 11 - 10 - 9 - 8

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC5 Result (1 path Rayleigh Fading)

• Velocity 30km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 15 - 14 - 13 - 12 - 11 - 10 - 9 - 8

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC5 Result (1 path Rayleigh Fading)

• Velocity 100km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 16 - 15 - 14 - 13 - 12 - 11 - 10 - 9 - 8

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC5 Result (2 path Rayleigh Fading)

• Velocity 3km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 15 - 14 - 13 - 12 - 11 - 10 - 9

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC5 Result (2 path Rayleigh Fading)

• Velocity 30km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 15 - 14 - 13 - 12 - 11 - 10 - 9

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

RC5 Result (2 path Rayleigh Fading)

• Velocity 100km/hr, (Îor1 + Îor2 ) / Ioc = 3, 0, -3dB, Îor1/ Îor2 = 0dB

1.0E- 03

1.0E- 02

1.0E- 01

1.0E+00

- 15 - 14 - 13 - 12 - 11 - 10 - 9

Ec/Ior

FE

R

CUR(3dB)

PRO(3dB)

CUR(0dB)

PRO(0dB)

CUR(- 3dB)

PRO(- 3dB)

Conclusions

• We proposed a New Soft Handoff Scheme to achieve “coding diversity gain”

• Except for RC 3, more than 0.5dB gain is achievable

• Even for RC 3, no negligible effects can be found

• The proposed Handoff Scheme provides seamless and transparent handoff to users

27SH31599.ppt