Mapping rule for Constellation Rearrangement IEEE Presentation Submission Template (Rev. 9) Document Number: IEEE C802.16m-09/0345 Date Submitted: Source: Hyungho Park, Sukwoo Lee Voice: LG Electronics, LG R&D Complex, 533 Hogye-1dong, Dongan-gu, Anyang, , Korea * Re : C80216m-08/053r1 “Call for Comments and Contributions on Project m Amendment Working Document” for the topic of HARQ Purpose: To provide details on mapping rule for constellation rearrangement proposed in amendment text of HARQ PHY Notice: This document does not represent the agreed views of the IEEE 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 Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and. Further information is located at and.

Introduction Constellation Rearrangement (CoRe) is considered as baseline HARQ scheme in the current IEEE m SDD text Key features –CoRe is cost-effective solution to enhance HARQ performance with low complexity –In deployment, CoRe doesn’t give any effect to FEC block, MIMO structure considered in IEEE802.16m –With increased modulation order, CoRe has significant performance gain regardless of resource allocation and MS’s mobility. At Denver meeting, we proposed the details of CoRe mapping rule. –In C802.16m-08_807r1, CoRe with consideration of MIMO configuration was introduced at Denver meeting. –In this contribution, simulation results of CoRe will be provided for support of Amendment text related to CoRe’s mapping rule.

Constellation Rearrangement [1] Proposed Constellation Rearrangement –Horizontal bitwise mapping Swapping operation exchanges component bits (i 1, q 1, i 2, q 2 ) on signal constellation in order to average the difference of bit error probabilities. Inversion operation averages out error probabilities of candidate component bits by taking inversion of the corresponding bits on signal constellation –Vertical bitwise mapping perform to exchange component bits between transmit antennas for averaging the channel difference.

Constellation Rearrangement [2] Illustrative example of proposed CoRe for 16 QAM –1 st retransmission Horizontal bitwise mapping: swapping bit reliability between MSB and LSB Vertical bitwise mapping : exchanging to average spatial channel difference between MSBs –2 nd retransmission Horizontal bitwise mapping: inversion of LSBs for averaging out the difference of bit reliabilities between candidate component bits(10, 11, 01, 00) Vertical bitwise mapping: exchanging to average spatial channel difference between LSBs

CoRe version [1] Rank of 1 CRVMapping rule Operation 0 Initial transmission 1 Swapping MSB with LSB 2 Inversion of LSB 3 Inversion of MSB Swapping MSB with LSB CRVMapping rule Operation 0 Initial transmission 1 Swapping MBS with LSB, Inversion of SB 2 Inversion of LSB 1 bit left circular shifting for In-phase/ Quadrature-phase, respectively 3 Inversion of SB 16 QAM 64 QAM

CoRe version [2] Mapping rule of 16 QAM (Rate 2) CRVMapping ruleOperation 0 Initial transmission 1Exchanging MSB of data stream 1 with MSB of data streams 2 Swapping MSB with LSB 2Inversion of LSB Exchanging LSB of data stream 1 with LSB of data streams 2 4Inversion of MSB Exchanging MSB of data stream 1 with MSB of data stream 2 Swapping MSB with LSB

CoRe version [3] Mapping rule of 64 QAM (Rate 2) CRVMapping ruleOperation 0 Initial transmission 1 Swapping MSB with LSB, Inversion of SB Exchanging In-phase of data stream 1 with In-phase of data streams 2 2 Inversion of LSB Exchanging data streams except MSB of Quadrature-phase 1 bit left circular shifting for In-phase/Quadrature-phase, respectively 3Inversion of SB Exchanging In-phase of data stream 1 with In-phase of data streams 2

Performance Result [1] Simulation Parameters ParametersAssumption Bandwidth10 MHz Number of subcarriers1024 Frame length5ms Channel estimationPerfect Channel codeCTC 1/2 Modulation16QAM, 64QAM MIMO configurationTx: 2, Rx:2 Resource allocationPUSC Channel modelVEH A MS mobility30km/h, 120km/h Receiver typeLinear MMSE Maximum number of retransmissions1, 2, 3 Retransmission latency10ms

Performance Result [2] Comparison of proposed CoRe and Chase/IR HARQ –Proposed CoRe obtains approximately 2~3dB FER gain over Chase HARQ regardless of MS’s mobility –Proposed CoRe shows little improvement in link performance gain over CTC-IR HARQ Performance gain (10% FER) CoRe vs Chase (30 km) CoRe vs Chase (120 km) CoRe vs IR, (30km) CoRe vs IR (120 km) N re = 11.7 dB1.9 dB0.30 dB0.35 dB N re = 22.1 dB2.2 dB0.15 dB N re = 32.8 dB3.1 dB0.47 dB N re :Maximum number of retransmission

Performance Result [3] Chase HARQ w/ CoRe vs Chase HARQ (16QAM rate 2)

Performance Result [4] Chase HARQ w/ CoRe vs IR HARQ (16QAM, rate 2)

Performance Result [5] 64 QAM (rate 2)