System Level Performance Evaluation on Multiplexing of USCCH in IEEE 802.16m IEEE 802.16...

System Level Performance Evaluation on Multiplexing of USCCH in IEEE 802.16mIEEE 802.16 Presentation Submission Template (Rev. 9) Document Number:

IEEE C802.16m-08/671r1Date Submitted:

2008-07-16Source:

Hyunkyu Yu, Jaeweon Cho, Taeyoung Kim, Mihyun Lee, Jeongho Park, [email protected], [email protected] Heewon Kang, Hokyu Choi , Rakesh TaoriSamsung Electronics

Yi Hsuan, Ping Wang, Hujun Yin [email protected], [email protected], [email protected] Intel Corporation

Jun Yuan, Sophie Vrzic, Dongsheng Yu, Mo-Han Fong, Robert Novak, [email protected], [email protected], [email protected] Nikopourdeilami, Kathiravetpillai Sivanesan, Sang-Youb KimNortel Networks

Sungcheol Chang, Hyun Lee [email protected] ETRI

Venue:IEEE 802.16m-08/024, “Call for Comments and Contributions on Project 802.16m System Description Document (SDD)”. Target topic: “DL Control Structure”.

Base Contribution:None

Purpose:To be discussed and adopted by TGm for the 802.16m SDD

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.

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System Level Performance Evaluation on Multiplexing of USCCH in IEEE 802.16m

Hyunkyu Yu, Jaeweon Cho, Taeyoung Kim, Mihyun Lee, Jeongho Park, Heewon Kang, Hokyu Choi, Rakesh Taori

Samsung Electronics

Yi Hsuan, Ping Wang, Hujun Yin

Intel Corporation

Jun Yuan, Sophie Vrzic, Dongsheng Yu, Mo-Han Fong, Robert Novak, Hosein Nikopourdeilami, Kathiravetpillai Sivanesan, Sang-Youb Kim

Nortel Networks

Sungcheol Chang, Hyun Lee

ETRI

July, 2008

Multiplexing of USCCH and Data

Options

(1) FDM (2) TDM (3) Hybrid FDM/TDM

Proposed Scheme FDMFDM

Rationale: Gain over TDM

• Data throughput gain: 6~30%

• Capacity (# of supportable users) gain: > 80%

• Link level performance gain

Proposed Change to SDD Text

• Within a sub-frame, control and data channels are multiplexed using FDM. Both control and data channels are transmitted on logical resource units (LRU) that span all OFDM symbols in a sub-frame.

Annex 1, 2, 3

Why FDM is better than TDM?

More efficient Power Sharing

Higher Throughput

• FDM: Power sharing

between Data and USCCH

• TDM: Power sharing

within USCCH only

Better Granularity

Smaller Resource Loss

• FDM: E.g. 108 tones (1 SubCH x 6 symbol)

• TDM: E.g. 864 tones (48 SubCHs x 1 symbol)

TDMTDMFDMFDM

Con

trol

IE #

1C

ontr

ol IE

#2

Con

trol

IE #

3

Large Granularity

Resource loss

No power sharing

Efficient power sharing

Control IE #1

Control IE #2Control IE #3

Small Granularity

possible

Annex 1: System Level Performance Evaluation on Multiplexing of USCCH in IEEE 802.16m

Hyunkyu Yu, Taeyoung Kim, Mihyun Lee, Jeongho Park, Jaeweon Cho, Heewon Kang, Hokyu Choi

Samsung Electronics Co., Ltd.

FDM vs. TDM

Performance Metrics FDM TDM

GRANULARITY of Ratio btw Control and Data (1-D MAP region)

HIGHER Lower (especially for short-length sub-frame)

COVERAGE (Outage) BETTER Worse

SPECTRAL EFFICEINCY (Sector Throughput)

BETTER Worse

CHANNEL ESTIMATION BETTER Worse

Processing Time (Latency) Longer

Shorter

TRADE-OFF between CH. est. performance and benefit of latency

Power Saving: Micro-sleep (in one Sub-frame)

Not support

Support

TRADE-OFF between CH. est. performance and benefit of micro-sleep

NOT significant gain within a sub-frame (<3%) [Annex]

98.6197.47

6 9

DELTAMARGIN (dB)

TDM: DL 3 UL 3 users

89.37

87.20

6 9

DELTAMARGIN (dB)

TDM: DL 4 UL 4 users

100.0 100.0

70

75

80

85

90

95

100

6 9

AV

AIL

AB

ILIT

Y (%

)

DELTAMARGIN (dB)

FDM: DL 8 UL 8 users

Comparisons btw TDM and FDM (1) Performance Metric

• With fixed orthogonal resource overhead, How many users can be supported with satisfying MAP outage requirement (<3%)?

• MAP outage is controlled by ∆MARGIN

TDM• Even if ∆MARGIN is increased, TDM

cannot support more than DL3, UL3 users

FDM• Enable to support DL8, UL8 users

without change of resource OH

MUXOrthogonal Resource

Overhead

FDM 16.7%

TDM 16.7% (1 OFDMA symbol)

*16.7%: Enable to support Maximum DL8 UL8 assignment blocks

97%

Availability (%) = 100 – MAP outage

Comparisons btw TDM and FDM (2) Performance Metric

• Maximum SECTOR THROUGHPUT with satisfying MAP outage requirement (<3%)

• GRANULALITY of resource ratio between data and control

• FDM: Resource + Power (SOFT Separation)

• TDM: Resource (HARD Separation)

FDM yields BETTER throughput performance than TDM

MUX# of Users (DL, UL)

Orthogonal Resource Overhead

∆MARGIN

FDM

(2, 2) 8.3% 6dB

(3, 3) 8.3% 5dB

(4, 4) 8.3% 5dB

(5, 5) 16.7% 5dB

TDM

(2, 2) 16.7% 4dB

(3, 3) 16.7% 4dB

(4, 4) 33.3 % 2dB

(5, 5) 33.3 % 4dB

5.0

6.0

7.0

8.0

(2, 2 ) (3, 3) (4, 4) (5, 5)

SEC

TO

R T

HR

OU

GH

PU

T (

Mbps)

NUM. of (DL, UL) TX. USERS

FDM TDM

System Level Simulation (1)

Performance Metrics

• Sector Throughput with satisfying MAP outage requirement

• MAP Outage requirement: Distribution of user whose BLER is larger than 1% < 3% of total users

Per User Power Control

• PMAPIE[i] = SINRREQ– SINR(CQI)[i] + ∆MARGIN

• SINRREQ: SINR value required to satisfy 1% BLER

• SINR(CQI)[i]: i-th user SINR set by CQI feedback value

• ∆MARGIN: Margin value to accomplish required MAP outage


Major Assumptions

• Subframe structure

• [IEEE C802.16m-08/062r1]

• Only assignment block in MAP region

• 48 bits (including CRC) per assignment block

• Separate coding

• 1-D MAP region indication

• Period: Semi-static

MUXOrthogonal Resource

Overhead

FDM 8.3 or 16.7 %

TDM 16.7 or 33.3 %

Assign.#2

Assign. Assign.#1

Assign.#N

Assign.#2

Assign.

TDMFDM

Assign.#N

Subframe (6 symbols)

DATATraffic

DATATraffic

...Assign....

Assign.#1

...

Zero insertion

1 or 2 OFDMA symbols

NR

U,T

OT

AL

1/12

or

1/6 ⅹ

NR

U,T

OT

AL

* 8.3%: Maximum DL4 UL4 assignment blocks 16.7%: Maximum DL8 UL8 assignment blocks 33.3%: Maximum DL16 UL16 assignment blocks


Simulation Environments/Assumptions

Index Value

Deployment Scenario EMD baseline [IEEE 802.16m-07/037r2 ]

MCS for MAP QPSK, 1/2

HARQSynchronous

(No assignment message for retransmission)

Scheduler Proportional fairness

# of Users per Sector 10

# of Scheduled Users2, 3, 4, 5 per mini-frame

(4, 6, 8, 10 for both DL and UL)

MAP Error Effects Resource loss for MAX retransmission

Antenna Configuration SIMO 1x2

Channel ModelMixed (Ped B-3kmph-60%,

Veh A-30kmph-30%, Veh A-120kmph-10%)

Channel EstimationReal channel estimation

(Equal impairment for both TDM and FDM)

Other Simulation Assumptions EMD baseline

Power Saving (1)

Micro-Sleep (within a sub-frame)

• Symbol level power saving

Power Saving Gain

Required Time

FFT 1 symbol

MAP Region p symbols p=1

Pilot Region q symbols q=2

CH. Est. Delay 0.5 symbol

MAP Decoding Minimum 1 symbol

Turn-off + Turn-on x0, x1, x2

2

0

3.5 ( , )%

6i

i ii

Max p q xPSG z G

PartsPortion of

Power Consumption

Time for turn-off + turn-on

Power Saving

Gain (%)

Baseband Modem z0 0.1 x0 1 symbols G1 50

RF Parts z1 0.65 x1 1 symbols G2 30

Display Device z2 0.25 x2 - G3 -

= 2.04 % Power saving gain by Micro-sleep is NOT significant

Power Saving (2)

Default Subframe Concept

• Sub-frame level power saving

• Power saving gain can be much larger than Micro-sleep

• One of sub-frame is pre-assigned to a MS as a default sub-frame,

then the MS may go sleep mode during other sub-frame

DL subframe

TT

G

RT

G

UL subframe

UL Data

ACK for DL

DLSubframe

#0

DLSubframe

#1

DLSubframe

#2

DLSubframe

#3

DL Data

DL MAP

ACK for UL

UL MAP

DLSubframe

#4

ULSubframe

#0

ULSubframe

#1

ULSubframe

#2

UL Data

ACK for DL

DLSubframe

#3

DL Data

DL MAP

ACK for UL

UL MAP

ULSubframe

#1Power Off Power Off Power Off

BS

MSi

Annex 2: Evaluation Results of 802.16m

DL Control Structure

Yi Hsuan, Ping Wang, Hujun Yin

Intel Corporation

Multiplexing Criteria II: Coverage Analysis 866m Cell (EMD Baseline Configuration)

Test Scenarios QPSK ½ coverage

QPSK ¼ coverage

QPSK 1/8 coverage

QPSK 1/12 coverage

Outage

FDM, Ped B

Reuse 1, CDD 46.8% 67.2% 93% 98.4% 1.6%

TDM, Ped B

Reuse 1, CDD 44.5% 64.4% 89.3% 96.5% 3.5%

FDM, Veh A

Reuse 1, CDD 44.2% 62.8% 89.4% 96.2% 3.8%

TDM, Veh A

Reuse 1, CDD 43.1% 61.6% 85.4% 94.7% 5.3%

Multiplexing Criteria II: Coverage Analysis 5000m Cell with Open Rural Macrocell Pathloss

Model


QPSK ¼ coverage

QPSK 1/8 coverage

QPSK 1/12 coverage

Outage

FDM, Ped B

Reuse 1, CDD 21.6% 43.9% 73.8% 87.2% 12.8%

FFR, CDD 45.7% 80.2% 96.5% 100% 0

TDM, Ped B

Reuse 1, CDD 19.2% 41.1% 66.3% 81.3% 18.7%

FFR, CDD 42% 79.6% 96.5% 99.7% 0.3%

FDM, Veh A

Reuse 1, CDD 18.9% 38.9% 66.7% 79.9% 20.1%

FFR, CDD 43.5% 77.6% 96.4% 99.6% 0.4%

TDM, Veh A

Reuse 1, CDD 18.4% 36.6% 60.5% 77% 23%

FFR, CDD 44.8% 78.1% 94.6% 99.2% 0.8%

Multiplexing Criteria II: Coverage Analysis 5000m Cell with Baseline Pathloss Model


QPSK ¼ coverage

QPSK 1/8 coverage

QPSK 1/12 coverage

Outage

FDM, Ped B

FFR, CDDNo power boost

24.7% 38.9% 54.2% 66.2% 33.8%

FFR, CDD3 dB boost

31.5% 48.7% 65.6% 78.9% 21.1%

TDM, Ped B

FFR, CDD 23.6% 37.8% 51.7% 63% 37%

FDM, Veh A

FFR, CDDNo power boost

23.6% 35.9% 52% 62.3% 37.7%

FFR, CDD3 dB boost

30.4% 45.7% 64.3% 74.7% 25.3%

TDM, Veh A

FFR, CDD 23% 35.3% 48.4% 59.9% 40.1%

Multiplexing Summary FDM has better link level performance and coverage than TDM because

of channel estimation advantage for FDM.

FFR improves coverage significantly in all cell sizes

FDM allows power boosting for USCCH, which can improve the cell coverage in some cases.

Annex 3:Performance Evaluation for IEEE 802.16m

Downlink Control Structure

Jun Yuan, Sophie Vrzic, Dongsheng Yu, Mo-Han Fong, Robert Novak, Hosein Nikopourdeilami,

Kathiravetpillai Sivanesan, Sang-Youb Kim

Nortel Networks

Link Level Simulation Assumptions

Parameters Values

Bandwidth 10 MHz

FFT size 1024

Carrier Frequency 2.5 GHz

Channel Model Pedestrian B 3 km/hr,ITU-Vehicular A 120 km/hr,

DL Tx scheme 2 Tx antenna, STBC

DL Rx scheme 2 Rx antenna

Permutation andsymbol structure

16e PUSC (baseline permutation in EMD)

Channel Coding 16e CTC

MCS QPSK ½ with repetition 0, 2, 4 and 6.

Channel Estimation MMSE based on all pilots in 2 symbols for TDM and 6 symbols for FDM

Table 1.1: Link Level Simulation ParametersTDM FDM

Pilot for antenna 1

Pilot for antenna 2

Figure 1: Pilot Design

Link Level Performance Results (1/2)

-15 -10 -5 0 5 1010

-2

10-1

100

SNR

BLE

R

FDM QPSK, STTD 2x2, VA 120km/h

1/12 ideal1/12 est1/8 ideal1/8 est1/4 ideal1/4 est1/3 ideal1/3 est1/2 ideal1/2 est2/3 ideal2/3 est

-15 -10 -5 0 5 1010

-2

10-1

100

SNR

BLE

R

TDM QPSK, STTD 2x2, VA 120km/h


-15 -10 -5 0 5 1010

-2

10-1

100

SNR

BLE

R

FDM QPSK, STTD 2x2, PB 3km/h


-15 -10 -5 0 5 1010

-2

10-1

100

SNR

BLE

R

TDM QPSK, STTD 2x2, PB 3km/h


Link Level Performance Results (2/2)

Code Rate TDM PB3km/h TDM VA120km/h FDM PB3km/h FDM VA120km/h

QPSK ½ rep 6 -2.3188 (dB) -1.5222 (dB) -4.1482 (dB) -3.794 (dB)

QPSK ½ rep 4 -1.7772 (dB) -0.9984 (dB) -2.8395 (dB) -2.8067 (dB)

QPSK ½ rep 2 0.3323 (dB) 0.5476 (dB) -0.5509 (dB) -0.5688 (dB)

QPSK ½ 3.5882 (dB) 3.4901 (dB) 3.0496 (dB) 2.9522 (dB)

Table 2: MCS SNR at 1% BLER

System Level Simulation Assumptions for Coverage Evaluation

Parameters Values

BS-to-BS distance1.5km urban 5.0km open rural microcell NLOS

Frequency reuse Reuse-1

Transmission power/sector 46 dBm

BS height 32 m

Tx antenna pattern 70o (-3dB) with 20 dB front-to-back ratio

Tx antenna gain 17 dBi

MS height 1.5 m

Rx antenna pattern Omni directional

Rx antenna gain 0 dBi

MS Noise Figure 7 dB

Penetration loss 10 dB

Hardware losses (Cable, implementation, etc.) 2 dB

Lognormal shadowing =0 dB, σSF =8 dB

Shadowing correlation 100% inter-sector, 50% inter-BS

Table 1.2: System Level Simulation Parameters

Coverage Performance

Table 3: MCS for 95% cell-edge users

TDM FDM w/o power boost FDM with 3dB power boost

1.5km PB3 Not Supportable QPSK ½ rep 6 QPSK ½ rep 4

1.5km VA120 Not Supportable QPSK ½ rep 6 QPSK ½ rep 4

5.0km PB3 Not Supportable Not Supportable QPSK ½ rep 6

5.0km VA120 Not Supportable Not Supportable QPSK ½ rep 6

-10 -5 0 5 10 15 200

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Geometry (dB)

CD

F

geo 1.5km Bs2Bs (sub)urban micro-cell

geo 5.0km Bs2BS rural macro-cell

1.5km urban: 95% SNR = -3.70dB5.0km rural: 95% SNR = -5.88dB

System Level Simulation Assumptions for Capacity Evaluation

Parameters Values

Resource budget 30 slots

TDM USCCH region 30 subchannels by 2 symbols

FDM USCCH region 10 subchannels by 6 symbols

Other hybrid schemes Total data subcarriers in the region should be the same as the above TDM or FDM scheme.

Mininum resource unit Per MAP IE size

Power budget 46 dBm for TDM41.2 dBm for unboosted FDM (10 out of 30 subchannels are used so power budget should be 46-10log10(3)=41.2)44.2 dBm for 3 dB boosted FDM

Possible MCS QPSK ½, QPSK ½ repetition 2, QPSK ½ repetition 4, QPSK ½ repetition 6

Code scheme Separate encoding

CID size 0 bit (masked by CRC)

Start RB index 6 bits (or proposal specific value)

Allocated RB 5 bits (or proposal specific value)

Other L1/L2 information (data MCS etc.) x (5, 21,37)

CRC 16 bits

Total MAP IE sizes 32, 48, 64 bits (including CID, RB allocation and other L1/L2 information, and CRC)

Power Sharing Yes for TDM and FDM

BS-to-BS distance 1.5km

Table 4: Simulation Assumptions

Capacity Results

Table 5: Number of Supportable UsersPB 3km/h channel, 30 slots resources , at BLER = 1% realistic channel estimation

MAP IE size1.5km TDM 1.5km FDM

(gain)1.5km FDM Power Boost 3dB(gain)

32 24 27 (13%) 41 (70%)

48 14 19 (35%) 28 (100%)

64 11 14 (27%) 20 (81%)

sum 49 60 (22%) 89 (81%)

Table 6: Number of Supportable UsersVA 120km/h channel, 30 slots resources , at BLER = 1% realistic channel estimation

MAP IE size1.5km TDM 1.5km FDM

(gain)1.5km FDM Power Boost 3dB(gain)

32 20 27 (35%) 41 (105%)

48 14 18 (28%) 28 (100%)

64 10 14 (40%) 20 (100%)

sum 44 59 (34%) 89 (102%)

Summary of Multiplex Schemes

FDM outperforms TDM • From coverage perspective

• Cell-edge users are supportable by FDM with power boost

• Cell-edge users are not supportable by TDM

• From capacity perspective• FDM (with power boost) achieves more than 20% (80%) capacity gain over TDM

Reasons• FDM has ~2dB link level gain due to time-direction de-noising.

• FDM has 3dB power boost gain.

System Level Performance Evaluation on Multiplexing of USCCH in IEEE 802.16m IEEE 802.16...

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