March 2017

doc.: IEEE 802.11-17/0451r0

Modified Channel Model For Outdoor OpenArea Hotspot Access Scenario
Date: 2017-03-13
Authors:
Name

Affiliations

Minseok Kim

Niigata
University
Niigata
University
Niigata
University
Tokyo Instituteof Technology

Kento Umeki
Shigenobu
Sasaki
Jun-ichi Takada

Submission

AddressSlide 1

Phone

email

+81-25-2627478

mskim@ieee.org+81-25-2626737+81-3-57343288

shinsasaki@ieee.org
takada@ide.titech.ac.jp

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Abstract• This contribution proposes a modified channel modelfor Open Area Outdoor Hotspot Access scenario
considering dominant reflected paths from surrounding walls

Submission

Slide 2

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Introduction• Our previous contribution (IEEE802.11-16/0342r0 [1])• Measurement campaign in an outdoor Open Area Hotspot Accessscenario• Investigation of dominant propagation mechanisms• Channel model parameter extraction (Q-D model)• This contribution• Propose simple and more realistic model considering dominantreflected paths from sur-rounding walls• Channel model parameters revised• SU-MIMO (Conf #1) performance evaluation

Submission

Slide 3

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Channel Modeling

Submission

Slide 4

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

IEEE802.11ay Q-D Channel Model• Quasi-deterministic model based on MiWEBA [2]• Deterministic components (D-Ray)• LoS, Ground reflection, Near-wall reflection• Determined by the location of Tx and Rx in the surrounding
environment
Tx• Reflection from far-away static objects
and random objects• Statistically modeled

HTx• Random components (R-Ray)

Tx

Rx

φ
L Access
Open Area Hotspot
Scenario [2]Submission

Slide 5

Minseok Kim, Niigata University

RxMarch 2017

doc.: IEEE 802.11-17/0451r0

Problem of Existing Open Area Hotspot
Channel Model• In most cases, the environment are surrounded by a
few buildings• Dominant wall reflection should be counted as a D-Ray

Map data @Google,ZENRIN
Submission

Slide 6

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Modified Channel Model: D-Ray• New D-ray components are calculated by the firstorder reflection from the surrounding walls of thespecific environment as

Wall B

Wall B
BS

BS
MS

Wall C
Wall A
Submission

Wall A
Slide 7

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Modified Channel Model: R-Ray
Statistical parameters of R-Ray were extracted from ray
tracing simulations
RT sim (Ref. cnt <=2)16

Elimination of LoS
and GR
Wall B

75

Removal of first-orderwall reflection（>-10dB LoS)

RT sim（Ref. cnt<=1)

Bandwidth limit &Peak detection

Wall C
Wall A
1200 (16 × 75) points (1 m spacing)Submission

R-Ray
Parameterization
Slide 8

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Channel Parameters
Deterministic components• Loss is calculated by Friis
equation and Fresnel reflection
equation• AoA (Angle-of-arrival), AoD(Angle-of-departure) and delay
are determined by the locationof Tx and Rx
D-Ray

Random components• No Clusters, 𝑁𝑁𝑐𝑐
• Cluster arrival rate, 𝜆𝜆• Cluster power-decay constant, 𝛾𝛾• Ray 𝐾𝐾 factor• AoA and AoD

LoS RayKτ0
Submission

Slide 91/λ

R-Ray Cluster
Power

τ0+τ1

R-Ray

time
Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Delay

R-Ray Parameters
No. Clusters, 𝑁𝑁𝑐𝑐
Cluster arrival time offset, 𝜏𝜏0Cluster arrival rate, λpower-decay constant, γ
K factor
Elevation

Angle

AoA
AzimuthElevation
AoD
AzimuthThis model

IEEE802.11ay [3]N(1.7,0.8)
40 ns
0.0084 ns-1
27.4 ns
7 dB

30.05 ns-1
15 ns
6 dB

𝐴𝐴AoA = 0.85
𝐵𝐵AoA = 1.9
2
𝜎𝜎AoA= 3.5 ※1

U[−180 : 180 °]𝐴𝐴AoD = 1.4
𝐵𝐵AoD = 2.2
2
𝜎𝜎AoD= 2.7 ※2

U[−180 : 180 °]2※1: 10−𝐴𝐴AoA ×𝐷𝐷−𝐵𝐵AoA + 𝑁𝑁(0, 𝜎𝜎AoA)

Submission
Slide 10[3] MiWEBA,FP7 ICT-2013-EU-Japan, http://www.miweba.eu

U[-20 : 20°]
U[−180 : 180 °]U[-20 : 20°]
U[−180 : 180 °]2※2 :−10−𝐴𝐴AoD ×𝐷𝐷−𝐵𝐵AoD + 𝑁𝑁(0, 𝜎𝜎AoD)

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Evaluation

Submission

Slide 11

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Measurement Campaign
Frequency
Bandwidth

8 Points (2 𝑚𝑚 spacing)BS

Submission

58.5 GHz

400 MHz

SignalMultitone

No. tones

256

Delay res.

2.5 nsMS

Slide 12

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Measurement Campaign (cont’d)
Full polarimetric double-directional measurement [4]Tx Antenna 15dBi Pyramidal Horn
Rx Antenna 15dBi Pyramidal Horn
Tx Antenna Rotation

Az:-180~+180, El:-30~+30
Step:30 deg.

Rx Antenna Rotation

Az:-180~+180, El:-30~+30
Step:30 deg.

Submission

Slide 13

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Data Processing• Double directional channel impulse response
AoA

AoD

Polarizationp ∈ 𝜗𝜗, 𝜑𝜑q ∈ 𝜗𝜗, 𝜑𝜑′′ℎqp 𝜏𝜏, 𝜗𝜗𝑖𝑖 , 𝜑𝜑𝑗𝑗 , 𝜗𝜗𝑚𝑚
, 𝜑𝜑𝑛𝑛′ = ℱ −1 𝐻𝐻qp 𝑓𝑓, 𝜗𝜗𝑖𝑖 , 𝜑𝜑𝑗𝑗 , 𝜗𝜗𝑚𝑚
, 𝜑𝜑𝑛𝑛′• Double directional angle delay power spectrum(DDADPS)′′
𝑃𝑃qp 𝜏𝜏, 𝜗𝜗𝑖𝑖 , 𝜑𝜑𝑗𝑗 , 𝜗𝜗𝑚𝑚
, 𝜑𝜑𝑛𝑛′ = ℎqp 𝜏𝜏, 𝜗𝜗𝑖𝑖 , 𝜑𝜑𝑗𝑗 , 𝜗𝜗𝑚𝑚
, 𝜑𝜑𝑛𝑛′Submission

Slide 142

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Data Processing (cont’d)• Synthetic spectrum (omni-directional)
Angular power
spectrumPower delay profile

APSqp 𝜗𝜗𝑖𝑖 , 𝜑𝜑𝑗𝑗 =PDPqp 𝜏𝜏 =1′
∑𝜏𝜏,𝑚𝑚,𝑛𝑛 𝑃𝑃qp 𝜏𝜏, 𝜗𝜗𝑖𝑖 , 𝜑𝜑𝑗𝑗 , 𝜗𝜗𝑚𝑚
, 𝜑𝜑𝑛𝑛′𝜁𝜁Tx

1′∑𝑖𝑖,𝑗𝑗,𝑚𝑚,𝑛𝑛 𝑃𝑃qp 𝜏𝜏, 𝜗𝜗𝑖𝑖 , 𝜑𝜑𝑗𝑗 , 𝜗𝜗𝑚𝑚
, 𝜑𝜑𝑛𝑛′𝜁𝜁Tx 𝜁𝜁Rx

Gain correction• Polarization combination
1
2

APSΣ 𝜗𝜗𝑖𝑖 , 𝜑𝜑𝑖𝑖 = ∑p∈ 𝜗𝜗,𝜑𝜑 ∑q∈ 𝜗𝜗,𝜑𝜑 APSqp 𝜗𝜗𝑖𝑖 , 𝜑𝜑𝑗𝑗
1
2

PDPΣ 𝜏𝜏 = ∑p∈ 𝜗𝜗,𝜑𝜑 ∑q∈ 𝜗𝜗,𝜑𝜑 PDPqp 𝜏𝜏Submission

Slide 15

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Channel Reconstruction
Measurement#Wall B

#Wall A

Ray Tracing#Wall B
#Wall A
#LoS

#LoS

Wall B
BS

1
IEEE802.11ay

Proposed#Wall B

MS

141

#Wall A#LoS

#LoS

Submission

Slide 16

Wall A

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

MIMO Beamforming (MIMO BF)• IEEE802.11ay SU-MIMO [3]Single polar (V-pol) 2×2 MIMO transmission  2 Streams
Configuration #1
Phased Antenna Array
Each element has
single polarization

V pol

E

Device #1

H pol
or

E

Beam #1

Device #2

Beam #2
H or V pol

H or V pol

Device #1

Device #2
Beam #1

Signal 1st stream

Beam #2

Phase shifter

H or V pol

PAA element

H or V pol

Signal 2nd stream

Submission

Slide 17

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

MIMO Channel Selection Metric• Based on IEEE802.11-16/1209r0 [5]• 𝑯𝑯 is generated by Ray-based search• Per-subcarrier capacity metric
𝐶𝐶 = det 𝑰𝑰 +

𝑃𝑃𝑡𝑡
𝑯𝑯𝑯𝑯H
𝑃𝑃n

[bits/s/Hz]

𝑯𝑯 =

𝐻𝐻11
𝐻𝐻21

𝐻𝐻12
𝐻𝐻22

• TX and RX antenna arrays••••

Submission“Gaussian” antenna pattern (equivalent to 8x8 antenna array).
Gain 24 dBi, Beamwidth 12°
Vertical polarization
Ideal beam steering: antenna broadside is rotated in the desired
direction

Slide 18

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Average Channel Capacity
BS

A壁

R-ray selected
MS C壁

Raytracing
BS
MS

IEEE 802.11ay

IEEE 802.11ay

B壁
BS
MS

This model
Submission

LoS and GR paths are used for parallel channels
Some times strong R-ray is employ for the 2nd path

A壁

Proposed model
Wall-A or Wall-B are realistically selected for the 2nd path
Channel capacity is well matched to those of RT results
Slide 19

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

Summary• Existing open area hotspot channel model doesn’t
consider surrounding walls

Our environment

Open square in Berlin (MiWEBA)Open square in Helsinki(METIS, ,mmMAGIC)• This contribution proposed a modified model including
dominant first-order wall reflection as D-Ray• SU-MIMO Capacity Evaluation• Proposed model is well matched to that by detail Ray tracing• Simply adding the wall reflected paths in site-specific manner
provide better representation
Submission

Slide 20

Minseok Kim, Niigata University

March 2017

doc.: IEEE 802.11-17/0451r0

References[1] “Channel Model for Outdoor Open Area Access Scenarios,” IEEE Document 802.1116/0342r0, Mar. 2016.
[2] MiWEBA, FP7 ICT-2013-EU-Japan, http://www.miweba.eu[3] “Channel Models for IEEE 802.11ay,” IEEE Document 802.11-15/1150r2, Sept. 2015.
[4] Karma Wangchuck, Minseok Kim, Kento Umeki, Kento Umeki, Kentaro Saito, and Junichi Takada, ``Polarimetric Millimeter Wave Propagation Channel Measurement andCluster Properties in Outdoor Urban Pico-cell Environment,'' The 27th Annual IEEE
International Symposium on Personal, Indoor and Mobile Radio Communications(PIMRC2016), Sept. 2016.
[5] “Hotel lobby SU-MIMO channel modeling: 2x2 golden set generation,” IEEE Document802.11-16/1209r0, Sept 2016.

Submission

Slide 21

Minseok Kim, Niigata University