Current 16e subblock interleaver

Project IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>

Title CTC Bit grouping for IEEE 802.16m Amendment

Document Number

IEEE S802.16m-09/0665

Date Submitted

2009-03-09

Source(s) Jung Woon Lee, Zhigang RongHuawei Seunghoon Choi, Chiwoo Lim, Songnam Hong, Sung-Eun ParkSamsung Electronics, Co., Ltd.Zheng ZhaoSamsung China Telecom R&D center CiouPing Wu, Peikai Liao, Paul ChengMediaTek Inc.Du Ying, Luo ZhendongCATR

Voice: 1-972-543-5880E-mail: [email protected]: +82-31-279-5890E-mail: [email protected]

E-mail: [email protected]

E-mail:[email protected],[email protected]

Re: IEEE 802.16m-09/0012, “Call for Contributions on Project 802.16m Amendment Working Document (AWD) Content”.Target topic: “Channel Coding and HARQ”

Abstract We propose new CTC Bit grouping schemes for IEEE 802.16m amendment.

Purpose For discussion and approval by TGm. for the 802.16m amendment

Notice This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein.

Release The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.16.

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Current 16e subblock interleaver• All encoded symbols are split into 6 subblocks, A, B, Y1, Y2, W1, W2

• Each subblock is interleaved independently with BRO operation

• Formed to 4 interleaved blocks A, B, Y1/Y2, W1/W2, where Y1/Y2 and W1/W2

are symbol-by-symbol multiplexed sequence of Y1&Y2 and W1&W2,

respectively.

• Interleaved sequences are modulated sequentially

Current 16e subblock interleaver

A subblock B subblock Y1 subblock Y2 subblock W1 subblock W2 subblock

Subblock interleaver






Symbol Separation

Subblock Interleaver

Symbol Grouping

Current 16e structure• Problem

- There are 3 layers protection class for 64 QAM (Best: b2 & b5, Good: b1 & b4,

Worst b0 & b3)

- Mapping the interleaved bit into 64QAM constellation isn’t optimized

- Systematic bits and their parity mapped into worst layer are always mapped

into worst or good layer in form of burst.

- Turbo decoder performance is degraded as a pair bits (systematic, parity)

are always mapped into same layer position in 64QAM constellation.

- Input burst mapped into worst layer make the decoder performance worse

64QAM constellation

011

010

000

001

101

100

110

111

111 110 100 101 001 000 010 011

b2b1b0

b5b4b3

I

Q

b2 & b5 : Best layer

b1 & b4 : Good layer

b0 & b3 : Worst layer

Mapping example (Nep=384, R=1/3, 64QAM)•Sequence of A(0, 1, …, 63) and B(0, 1, …, 63) and their parity sequences Y1(0, 1, …, 63)

and W1(0, 1, …, 63) are always mapped into best layer (b2 or b5) according to current sub-

block interleaver design as shown in the attachment (below zip file)

•Sequences of A(64, 65, …, 127) and B(64, 65, …, 127) are mapped into good layer (b1 or

b4) and their parity sequence Y1(64, 65, …, 127) and W1(64, 65, …, 127) are mapped into

worst layer (b2 or b5)

•Sequences of A(128, 129, …, 191) and B(128, 129, …, 191) are mapped into worst layer

(b0 or b3) and their parity sequence Y1(128, 129, …, 191) and W1(128, 129, …, 191) are

mapped into good layer (b1 or b4)

SubIntOut.zip

Proposed Subblock interleaver A subblock B subblock Y1 subblock Y2 subblock W2 subblock W1 subblock







C-Symbol permutation




Proposed Subblock interleaver (Cont’)

where C is modulation order, R= N/C , R1= 2N/C . δ = 1 for 64QAM and δ = 0

for other modulation.

Ai(j), Bi(j), Y1/Y2i(j) and W2/W1i(j) are the permutation formula for j-th element of

i-th group of interleaved sub-block I(A) I(B), I(Y1/Y2) and I(W2/W1), respectively

• Subblock interleaver is same as 16e

• C-symbol Permutation formula for the proposed subblock

interleaver

1,...,0,1,...,0,mod))mod)1((()(1/2

1,...,0,1,...,0,mod))mod)1((()(2/1

1,...,0,1,...,0,mod))mod)1((()(

1,...,0,1,...,0,mod))mod(()(

1

1

RiCjCCijjWW

RiCjCCijjYY

RiCjCCijjB

RiCjCCijjA

i

i

i

i

Conclusions

• New scheme has up to 2.2 dB gain at (R=1/3, 64QAM), 1.0 dB gain at

(R=1/2, 64QAM) and 0.6dB gain at (R=2/3, 64QAM).

• In 16QAM, new schemes has up to 0.4dB gain

Simulation Parameters

• Channel Model: AWGN

• Turbo decoder: Max-log-map with 8 iterations

• Packet size: 48, 144, 256, 288, 384, 512, 960, 1216, 1920, 2048, 2880,

3840, 4800

• Code Rate: 1/3, 1/2, 2/3

Simulation ResultsFER comparison (Nep=48, AWGN)

0.001

0.01

0.1

1

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

SNR

FE

R

16e_64QAM (R=1/3) Proposed_64QAM (R=1/3) 16e_64QAM (R=1/2) Proposed_64QAM (R=1/2)




0.001

0.01

0.1

1

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

SNR

FE

R





0.001

0.01

0.1

1

2 3 4 5 6 7 8 9 10 11 12 13 14 15

SNR

FE

R





0.001

0.01

0.1

1

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

SNR

FE

R





1.00E-03

1.00E-02

1.00E-01

1.00E+00

2 3 4 5 6 7 8 9 10 11 12 13 14 15

SNR

FE

R





0.001

0.01

0.1

1

2 3 4 5 6 7 8 9 10 11 12 13 14 15

SNR

FE

R





1.00E-03

1.00E-02

1.00E-01

1.00E+00

2 3 4 5 6 7 8 9 10 11 12 13 14 15

SNR

FE

R




Current 16e subblock interleaver

Documents

Transcript of Current 16e subblock interleaver