The Softest Handoff Design Using Iterative Decoding (Turbo Coding) Byung K. Yi LGIC 3GPP2 TSG-C WG 3 Physical Layer Jan. 11, 2000

The Softest Handoff DesignUsing Iterative Decoding (Turbo Coding)

Byung K. YiLGIC

3GPP2 TSG-C WG 3 Physical LayerJan. 11, 2000

Presentation Outline

• Introduction and Motivation• IS-95 Soft Handoff Scheme• The Novel Forward Link System Model for the CCPC Handoff

Scheme• Simulation Results Over AWGN and Rayleigh Channels• Upper Bounding Performances Over AWGN and Rayleigh

Channels• Reverse Link System Model for the CCPA Handoff Scheme• Conclusions

2SH31599.ppt

Introduction and Motivation

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

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

• Turbo Codes have been adapted for the 3rd Generation Standards: CDMA 2000 (3GPP II) and 3GPP

• Are there techniques providing soft handoffs without increasing the transmitter power and bandwidth?

• Can we achieve a type of “Soft” Handoff for TDMA, FDMA, CDMA-to-CDMA System, or between various dual mode operations?

3SH31599.ppt

Introduction and Motivation (Cont’d)

• Are There Any Inherent benefits using the turbo code for next generation multi-media traffics beyond the Coding Gain?

• Answers Are “YES”• Code Combining and Packet Combining (CCPC) Scheme in

Conjunction With Iterative Turbo Decoding

4SH31599.ppt

IS-95 Soft Handoff

System Model for the Cellular Handoff

IS-95 System Models for the Forward Link

IS-95 CDMA Forward Link Receiver

IS-95 Soft Handoff

Maximal Ratio Combiner of the Forward Link

IS-95 Soft Handoff

System Model for the Reverse Link

The Novel Softest Handoff System Model for Forward Link

Transmitter for the CCPC Handoff

The Novel Softest Handoff System Modelfor Forward LinkDetailed Encoder for the CCPC Handoff for Code Rate 1/2

X1

+ D D D+

+

I

+ D D D+

+

Y1

X2

Y2

Puncturer#1

Puncturer#2

MUX

MUX

To Base StationA

To Base StationB

dk

The Novel Softest Handoff System Modelfor Forward LinkDetailed Encoder for the CCPC Handoff for Code Rate 1/3

X1

+ D D D+

++

I

+ D D D+

++

Y1

Y2

X2

Y3

Y4

Puncturer#1

Puncturer#2

MUX

MUX

dk

To Base StationA

To Base StationB


Detailed Signal Puncturing for the CCPC Handoff


Mobile Receiver for the CCPC Handoff


Detailed Decoder for the CCPC Handoff Scheme

Simulation Results for the Code Rate 1/2

BER over AWGN Channel

-2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 210

-6

10-5

10-4

10-3

10-2

10-1

Eb/No

BE

R

BER Comparison for the W/WO diversity Combining over AWGN channel

code rate 1/2 operationcode rate 1/4 CCPC diversity combined


FER over AWGN Channel

-2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 210

-3

10-2

10-1

100

Eb/No

FER

FER Comparison for the W/WO diversity Combining over AWGN channel



BER over Rayleigh Fading Channel


FER over Rayleigh Fading Channel

-2 -1 0 1 2 3 410

-3

10-2

10-1

100

Eb/No

FER

FER Comparison for the W/WO diversity Combining over Rayleigh Fading channel


Upper bounding Performance

BER over AWGN

-2 -1 0 1 2 3 4 5 610

-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

BE

R

BER Upper Bounding Performance Comparison for the W/WO diversity Combining over AWGN channel


Upper bounding Performance for Code Rate 1/2


FER over AWGN

-2 -1 0 1 2 3 4 5 610

-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER

FER Upper Bounding Performance Comparison for the W/WO diversity Combining over AWGN channel



Comparison between Simulations and Upper Bounding Results

Frame Error rates for AWGN Channel

-3 -2 -1 0 1 2 3 4 5 610

-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER

FER Comparison between simulation results and upper bounding performances

Simulation result for the code rate 1/2Simulation result for the code rate 1/4Upper bounding performance for the code rate 1/2Upper bounding performance for the code rate 1/4


Bit Error rates for AWGN Channel

-3 -2 -1 0 1 2 3 4 5 610

-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

BE

R

BER Comparison between simulation results and upper bounding performances



FER over AWGN Channel for Different TX Power Cases

-2 -1 0 1 2 3 4 5 610

-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER

FER Upper Bounding Performance Comparison for the different TX Power Cases over AWGN channel

CCPC diversity combined with PA=PBCCPC diversity combined with PB=PA-3dBCCPC diversity combined with PB=PA-6dBCCPC diversity combined with PB=PA-9dBW/O CCPC with Code Rate 1/2



BER over AWGN Channel for Different TX Power Cases



FER over Rayleigh Fading Channel for the Same TX Power Case

-1 0 1 2 3 4 5 6 710

-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER

FER Upper Bounding Performance Comparison for the W/WO diversity Combining over Rayleigh Fading channel




BER over Rayleigh Fading Channel for the Same TX Power Case

-1 0 1 2 3 4 5 6 710

-12

10-10

10-8

10-6

10-4

10-2

100

Eb/No

BE

R

BER Upper Bounding Performance Comparison for the W/WO diversity Combining over Rayleigh Fading channel




Frame Error rates for Rayleigh Fading Channel

-2 -1 0 1 2 3 4 5 6 710

-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER

FER Comparison between simulation results and upper bounding performances over Rayleigh Fading Channel



Bit Error rates for Rayleigh Fading Channel

-2 -1 0 1 2 3 4 5 6 710

-12

10-10

10-8

10-6

10-4

10-2

100

Eb/No

BE

R

BER Comparison between simulation results and upper bounding performances over Rayleigh Fading Channel


FER over Rayleigh Fading Channel for Different TX Power Cases

-1 0 1 2 3 4 5 6 7 810

-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER

FER Upper Bounding Performance Comparison for the different TX Power Cases over Rayleigh Fading channel




BER over Rayleigh Fading Channel for Different TX Power Cases

-1 0 1 2 3 4 5 6 7 810

-12

10-10

10-8

10-6

10-4

10-2

100

Eb/No

BE

R

BER Upper Bounding Performance Comparison for the different TX Power Cases over Rayleigh Fading channel



FER Performance Comparison between 2-UNINTER and UNINT+INTOver AWGN Channel

-1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 310

-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER

FER Upper Bounding Performance Comparison between the interleaved and the uninterleaved over AWGN

code rate 1/4 CCPC with INT and UNINT sys bit streamscode rate 1/4 CCPC with two UNINTs


BER Performance Comparison between 2-UNINTER and UNINT+INTOver AWGN Channel

-1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 310

-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

BE

R

BER Upper Bounding Performance Comparison between the interleaved and the uninterleaved over AWGN



BER Performance Comparison between 2-UNINTER and UNINT+INT Over Layleigh Fading Channel

-1 0 1 2 3 4 5 610

-12

10-10

10-8

10-6

10-4

10-2

100

Eb/No

BE

R

BER Upper Bounding Performance Comparison between the interleaved and the uninterleaved over Rayleigh



FER over AWGN

-2 -1 0 1 2 3 4 5 610

-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER

FER Comparison for the W/WO CCPC over AWGN channel



BER over AWGN

-2 -1 0 1 2 3 4 5 610

-12

10-10

10-8

10-6

10-4

10-2

100

Eb/No

BE

R

BER Comparison for the W/WO CCPC over AWGN channel




-2 -1 0 1 2 3 4 5 610

-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER




FER over AWGN Channel for Different TX Power Cases

-2 -1 0 1 2 3 4 5 610

-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Eb/No

FER





-2 -1 0 1 2 3 4 5 610

-12

10-10

10-8

10-6

10-4

10-2

100

Eb/No

BE

R

BER Upper Bounding Performance Comparison for the different TX Power Cases over AWGN channel



FER over Rayleigh Channel for Different TX Power Cases

-2 -1 0 1 2 3 4 5 610

-12

10-10

10-8

10-6

10-4

10-2

100

Eb/No

BE

R




BER over Rayleigh Channel for Different TX Power Cases

-2 -1 0 1 2 3 4 5 610

-12

10-10

10-8

10-6

10-4

10-2

100

Eb/No

BE

R



Conclusions

• We Proposed a New Soft Handoff Scheme Combining With CCPC Scheme With Iterative Turbo Decoding

• We Demonstrated Not Only an Unprecedented Coding Gain From Iterative Turbo Code, but Also More Than 3.2 dB and 4.0 dB Diversity Gains Due to the CCPC Scheme

• The CCPC Handoff Provides “the Softest” Handoff Mechanism for CDMA Systems

• The CCPC Handoff Can Allow a Type of Soft Handoff for TDMA, FDMA, CDMA-to- CDMA, or Between Dual Mode Operations

• The CCPC Handoff Scheme Provides Seamless and Transparent Handoff to Users

41SH31599.ppt

Documents

The Softest Handoff Design Using Iterative Decoding (Turbo Coding) Byung K. Yi LGIC 3GPP2 TSG-C WG 3 Physical Layer Jan. 11, 2000