July 2016

doc.: IEEE 802.11-16/0976r0
IEEE P802.11
Wireless LANs

Proposed Text for Informative Annex in the IEEE 802.11ay
Channel Model Document
Date: 2016-07-25
Author(s):NameMinseok Kim
Shigenobu
Sasaki
Kento Umeki
Tatsuki Iwata
KarmaWangchukJun-ichiTakadaAffiliation
Niigata University

Address
8050 Ikarashi 2-no-cho, Nishiku, Niigata, 950-2181 Japan

Niigata University
Niigata University
Niigata University
Tokyo Institute ofTechnology
Tokyo Institute ofTechnology

Phone

email

+81-25-262-7478

mskim@ieee.org+81-25-262-6737

shinsasaki@ieee.org+81-3-5734-3288

takada@ide.titec
h.ac.jp

Abstract
This contribution contains the proposed text on measurement results and simulations related to an
outdoor open area access scenario, which will be included to the proposed Informative Annex for theIEEE 802.11ay Channel model document [3]. Main text of this contribution is based on the authors’previous contribution [5].

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2.

doc.: IEEE 802.11-16/0976r0

Outdoor Scenario

2.1 Outdoor Open Area Hot Spot Access2.1.1 Measurement and Simulation Results at 58.5 GHz in Niigata University Campus2.1.1.1 Measurement Setups
In the measurement, the developed custom channel sounder that employed a commercial product of mmwave transmitter and receiver (V60TXWG1/V60RXWG1, VubIQ) was used [3]. Using 2 × 2 MIMO
configuration full polarimetric wideband channel transfer functions were simultaneously measured. The
transmit power of approximately 10 dBm. We exclude the influence of the measurement system from themeasured channel responses by full MIMO back-to-back calibration (direct connection between transmitterand receiver antenna ports with a waveguide and an attenuator). The measurement dynamic range is limited
to approximately 40 dB. The channel sounding parameters are presented in Table. 1.
The measurement campaign was conducted in an outdoor open square as shown in Fig. 1 where transmitteras an access point (AP) was located at around the center of the area and the channel transfer functions weremeasured at three positions of the mobile station (MS or STA). STA pos1 and STA pos2 were in LoS
condition and STA pos3 was in obstructed-LoS (OLoS) condition. The antenna heights were 3 m for AP
and 1.5 m for STA, respectively. The measurement site was surrounded by some large buildings whichwere located 20 ∼ 30 m away from the AP. The distance between AP and STA was approximately 30 m.
For acquisition of full polarimetric double-directional channel transfer functions, two orthogonallypolarized (ϕ and ϑ) high gain horn antennas were used at both sides of transmitter and receiver, where thoseantennas were not co-located but direct toward the opposite side (180 degrees) on the same plane. The APand STA antennas were rotated from 0 to 360 degrees in azimuth, and from −30 to 30 degrees in elevation.
Because the half power beam-width (HPBW) are 30 degrees (gain 15 dBi) for STA, and 12 degrees (gain24 dBi) for AP, respectively, the azimuth and elevation angles at AP and STA were varied in 12 and 30
degree steps, respectively.
Table 2.1: Channel sounding parameters

Submission

Carrier Frequency

58.5 GHz

Signal Bandwidth

400 MHz

Sampling Rate

800 MHz

Baseband signal

Unmodulated Multitone

FFT length

512

Tone Spacing

1.563 MHz

Delay Resolution

2.5 nsMaximum Delay

640 nsTransmitter Antenna

24dBi Pyramidal Horn

Receiver Antenna15dBi Pyramidal Horn

Transmitter Antenna Rotation

Az: 0~360 deg., El: 66~114 deg.
Step: 12 deg.

Receiver Antenna Rotation

Az: 0~360 deg., El: 60~120 deg.
Step: 30 deg.

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Obstructed LoS (OLoS)

3m

1.35m

AP

Line of Sight(LoS)
10m
Map data @Google, ZENRIN

AP (transm itter)

STA (receiver)

Figure 2.1: Measurement environment
2.1.1.2 Measurement Results
As described in [4], the angle delay power spectrum (ADPS) and angular power spectrum (APS) at bothsides of the AP and STA, and the omni-directional power delay profile (PDP) are synthesized from the
double-directional ADPS (DDADPS). For precise interpretation of the measurement results, the RT
simulation was used applying up to third- and second-order reflections for LoS and OLoS conditions,respectively. The used RT simulation tool employs the image method. The first-order diffraction was
further calculated only for OLoS condition based on uniform theory of diffraction (UTD). This simulation
calculated the ray parameters of the received power, time delay of arrival, angles of departure (AoD) andarrival (AoA) for each path. For comparison with the measurement results, the simulation based DDADPS
was reconstructed from the simulation results by using the radiation patterns of the used antennas, then theAPS and PDP were calculated in the same manner as the measurement.
The synthetic ADPSs seen from AP in terms of three different positions of the STA (MS) are shown in Fig.
2.2, where it can be seen that a few significant multi-path clusters are observed besides the LoS path andthe dominant paths in the RT results are well matched to those in the measurement results. In addition,comparing the measured and simulated APS of which power are overlapped on the panoramic environment
photos and RT simulation results, the propagation mechanism of each cluster has been identified. Some
examples are presented in Fig. 2.3.
Table 2 lists the propagation mechanism showing delay, excess loss to the LoS path gain and crosspolarization power ratio (XPR) of each cluster, where dominant propagation mechanisms include first- andsecond-order reflection from the walls of the neighboring buildings, first-order diffraction and scatteringby some small objects such as lamppost, tree and weather sheds, and first-order reflection with penetration
into glass.
From the channel modeling point of view, it can be concluded as follows. Only a few significant multi-pathclusters were observed, and those have relatively small power with the excess loss larger than 20 dB otherthan the first-order reflection from nearby buildings where the excess loss of the first-order reflection (thesecond largest cluster in LoS condition) was 11.4, 15.6 and 11.2 dB for STA_pos1, 2, and 3, respectively.
It is noted that the distance to the nearby walls was located a bit large from transmitter and receiver. It wasalso confirmed that when the STA was close to a building wall, the first-order reflected paths could havesignificantly large power. The first-order reflected paths can be predicted in a deterministic manner, andthose should be separately

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doc.: IEEE 802.11-16/0976r0WRWRTreeWeather WRshedWRWRLoS

LamppostGP&WRWREDLoS

GP&WRWRWRGP&WRWRLoSWR

WR

WR

WR

WeathershedGP&WR

WR

WRWR

WRWR

EDLoS

Figure 2.2: Angle delay power spectra (ADPS) observed at the AP in terms of three different positions ofSTA (LoS, WR, GP and ED are denoted by Line of Sight, Wall Reflection, Glass Penetration and EdgeDiffraction)

STA

AP

Single bounce wall reflection(a) STA_Pos1

STA
AP

Single bounce wall reflection(b) STA_Pos2

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Minseok Kim, et al., Niigata University

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STA

AP
Edge diffraction(c) STA_Pos3

Figure 2.3: Mechanism identification examples by using APS (left column) and RT output (right column)
2.1.1.3 Channel Modeling
From the above experimental study, a quasi-deterministic (Q-D) modeling approach is considered. Thatallows natural description of scenario-specific geometric properties, reflection attenuation and scattering,
ray blockage and mobility effects [2]. There already exist channel models for open area outdoor hotspot
access scenario in [2], where LoS and ground reflection are only considered as D-ray components anddetermined by the location of Tx and Rx in the surrounding environment assuming that there are no nearby
interacting objects in the vicinity of Tx and Rx. The R-ray components such as first- and high-orderreflection from far-away static objects and random objects are statistically modeled. Similar to this case as
shown in Fig.2.1, if there exists some significant interacting objects such as large buildings, it is reasonable
to treat the dominant specular reflection on them as additional Dray components. Based on Q-D model, thestatistical channel model parameters of the R-rays were extracted by using RT simulation for more than 300
Rx positions (LoS condition) where the first-order reflected paths from the building walls were eliminated from theestimated ray paths, then the intercluster parameters were calculated simply treating the estimated rays as a cluster.
The delay and angle domain parameters are found in [4].

Table 2.2: Identified propagation mechanisms
STAPosition

Delay
[ns]

MS_pos1
MS_pos2
Single-bounce Reflection
MS_pos2
MS_pos3
MS_pos1
MS_pos2
Double-bounce Reflection
MS_pos2
MS_pos3
Diffraction
MS_pos3
Scattering (Lamppost)
MS_pos2
Scattering (Tree)
MS_pos1
Scattering (Weather Shed) MS_pos2
Scattering (Weather Shed) MS_pos2
Scattering (Weather Shed) MS_pos3

125
127.5
132.5
180
172.5
197.5
210
260
107.5
120
122.5
157.5
177.5
192.5

Propagation Mechanism

Submission

Path
Excess Average Excess
XPR(TxV) XPR(TxH)
Gain
Loss [dB]
Loss [dB][dB]-105.6
10.3
6.39
2.5
-113.5
15.7
8.31
6.98
13.86
-113.7
15.9
8.36
8.91
-108
10.25
13.85
14.36
-110.4
15.1
10.16
6.41
-117.6
19.8
4.54
3.26
18.49
-116.3
18.5
4.29
6.87
-117
19.25
3.27
2.56
-115
17.25
17.25
0.45
10.14-115.5
17.7
7.13
6.65
-112.6
17.3
13.86
13.94
18.03
-116.6
18.8
1.64
8.09
-115.5
17.7
6.57
8.47
-116.2
18.45
6.45
0.8

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Minseok Kim, et al., Niigata UniversityJuly 2016

doc.: IEEE 802.11-16/0976r0

References:[1] IEEE Std. 802.11ad-2012, Dec. 2012.
[2] A. Maltsev, et al., Channel Models for IEEE 802.11ay, doc.: IEEE 802.11-15/1150r3, Mar. 2016.
[3] S. Sasaki and M. S. Kim, Proposed Structure of Informative Annex for the IEEE 802.11ay Channel
Model Document, doc.: IEEE 802.11-16/0549r0, Apr. 2016.
[4] M. Kim, H. K. Pham and J. Takada, “Development of Low-Cost 60-GHz Millimeter-Wave MIMO
Channel Sounding System,” Proc. GSMM 2013, Apr. 2013.
[5] M. Kim, et al., “Channel Model for Outdoor Open Area Access Scenarios,” IEEE 802.11-16/0342r1,Mar. 2016.

Submission

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Minseok Kim, et al., Niigata University