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Measurement and Characterization of Various Outdoor 60 GHz Diffracted and Scattered Paths
Research Paper / Feb 2014

 

Measurement and Characterization of Various Outdoor 60 GHz  

Diffracted and Scattered Paths 

 

 

 

Jonathan S. Lu1,2, Patrick Cabrol2, Daniel Steinbach2 and Ravikumar V. Pragada2 

 

Polytechnic Institute of New York University1, InterDigital Communications LLC2 

lushiaoen@gmail.com, Patrick.Cabrol@interdigital.com, Daniel.Steinbach@interdigital.com and 

 

Ravikumar.Pragada@interdigital.com 

 

 

 

Abstract— This paper investigates diffracted and scattered waves 

in unlicensed millimeter wave mobile-to-mobile, access and 

backhaul radio links. Narrowband 60 GHz measurements of 

diffraction at building corners, and scattering by a car, lamppost 

and building, as well as blocking by humans are presented. Semi-

analytical corner diffraction and human blocking models are 

proposed and verified based on the measurements. Analysis of 

the diffraction and scattering shows that the contributions from 

vehicular and lamppost scattered paths can be dominant 

compared to corner diffracted paths. Measurements also show 

that the majority of power from building scattering arrives in 

and near the horizontal plane containing the transmit and 

receive antennas.  

 

Keywords—60 GHz; Backhaul; Diffraction; Millimeter Wave; 

mmW; Mobile-to-Mobile; IEEE 802.11ad; IEEE 802.11aj; NLOS; 

Scattering 

 

I. INTRODUCTION  

     The 57–64 GHz millimeter wave (mmW) unlicensed band, 

also known as the 60 GHz band, allows for multi-gigabit data 

rates [1] with high spatial reuse. This has prompted the 

attention of short-range wireless personal area networks 

(WPAN) standards (e.g., Wireless HD, IEEE 802.15.3c and 

ECMA 387), and wireless local-area networks (WLAN) 

standards (e.g., WiGIG, IEEE 802.11ad and IEEE 802.11aj). 

Many indoor applications have been proposed, such as indoor 

cable-replacement for home and office multimedia streaming. 

Outdoor applications have also gained popularity. Currently 

backhaul is the predominant point-to-point outdoor use-case 

for mmW frequencies with the focus slowly moving towards 

mobile broadband systems. The 802.11ad standard allows for 

multiple simultaneous direct mobile-to-mobile 

communications [2]. It is envisioned that in mmW mobile 

wireless systems, mmW cells can be deployed utilizing 

existing street furniture, building corners or building surfaces 

avoiding the need for expensive dedicated mmW cell towers. 

 There is a plethora of literature summarized in [3], [4] on 

the wideband and narrowband channel parameters of 60 GHz 

indoor links. In comparison, there is a smaller amount of 

applicable literature [5], [6] on the channel parameters of 60 

GHz outdoor radio links and even fewer on the site-specific 

interactions with common outdoor radio link obstructions (e.g., 

buildings and cars).  In [5] and [6], it was found that there was 

large variability in the channel parameters due to these site-

 

specific features. Understanding the strong dependence of the 

channel parameters on these features requires further 

investigation into the propagation characteristics of the 

individual obstructions. 

 Whether a mmW system has sufficient SNR for a non-line-

of-sight (NLOS) link where one end of the radio link is 

shadowed is dependent on the rays propagating around and 

through the obstruction. For shadowing by a building, 

transmission loss through building materials at 60 GHz is very 

high [7], so it is expected that the diffraction at the building 

corner and scattering from objects near the corner will be the 

dominant modes of propagation.  Diffraction of simple objects 

such as wooden and metal blocks [8] has been studied, but to 

the best of the authors’ knowledge, there are no 60 GHz 

measurements characterizing building corner diffraction. 

Therefore, we have made measurements on corner diffraction 

and found that an absorbing screen diffraction coefficient best 

models our measurements.  

 For human shadowing, significant fades up to 50 dB [9] 

have been observed. Thus human blockers must be accounted 

for in RF prediction tools. Human blockers have been modeled 

as finite absorbing screens [8], [9], and water cylinders [10]. 

Verification of these models has generally only been done for a 

single mobile-to-mobile blocker scenario. In this work, we 

further verify the absorbing screen model for multiple humans 

blocking a mobile-to-mobile and a single human blocking an 

access link using uniform theory of diffraction (UTD) and 

physical optics. 

 For line-of-sight (LOS) communications, propagation paths 

other than the LOS path may need to be used because of 

temporary obstructions such as the aforementioned human 

blocking. In [5], it was found that NLOS paths near the LOS 

path generally had smaller delay spread and less loss relative to 

the LOS. These NLOS paths may arise from scattering from 

lamppost and other street furniture. Similarly for NLOS 

communications caused by building shadowing, this street 

furniture may give significant contributions for turning a 

corner as observed in UHF communications [11]. We have 

therefore performed a 60 GHz empirical study on vehicular, 

lamppost and building scattering. 

 Section II describes our measurement setup and scenarios. 

Simple diffraction models used to compare with our 

measurements are given in Section III. The measurements are 

presented and analyzed, and compared with the models of 

Section II in Section IV.  

 

2013 IEEE Military Communications Conference

 

978-0-7695-5124-1/13 $31.00 © 2013 IEEE

DOI 10.1109/MILCOM.2013.212

 

1238

 

2013 IEEE Military Communications Conference

 

978-0-7695-5124-1/13 $31.00 © 2013 IEEE

DOI 10.1109/MILCOM.2013.212

 

1238

 

 

 

II. MEASUREMENT SETUP AND PROCEDURE  

For all of our 60 GHz measurement scenarios, the same 

 

measurement equipment was used to record the received 

power. In the individual scenarios, the antenna heights and 

positioning varied as discussed below. 

 

A. Measurement Equipment Setup  

A diagram of our 60 GHz measurement equipment setup is 

 

shown in Fig. 1. In the transmit system (TX), the SMF100A 

microwave signal generator provides a 10 GHz sine wave to 

the SMZ90 frequency multiplier, which multiplies the 

frequency by six. The resulting 60 GHz signal then travels 

through a straight section waveguide to the V-band horn 

antenna with 24 dBi of gain and an 11 degree 3 dB beamwidth 

whose normalized antenna pattern is shown in Fig. 2. In the 

receive system (RX), the signal is received with an identical 

horn antenna that is connected to the N12-3387 low noise 

amplifier (LNA) with a straight waveguide section. The 

amplified signal is sent to the FS-Z90 harmonic mixer where it 

is down-converted and captured on the FSQ26 vector signal 

analyzer (VSA).  

 

B. Measurements from Building, Car, and Lamppost  

To perform outdoor measurements on buildings, cars, and 

 

lampposts shown in Fig. 3, the transmit (TX) and receive (RX) 

systems illustrated in Fig. 1, were each placed on push carts. 

To accurately point the antennas, the antennas were placed on 

pan-tilt motors of 0.0032� angle resolution, which were 

attached to the carts. Laptops on both carts ran a C++ program 

that was developed to control the motors, query the VSA for 

the received signal power and store measurement data.  

 

The antennas’ heights hTX and hRX relative to the ground for 

these measurement scenarios were 1.33 m and characterize a 

mobile-to-mobile radio scenario. Because the building 

scattering measurements were performed for sufficiently short 

link lengths in which the contribution from ground reflections 

was severely attenuated by the antenna pattern, these 

measurements should also apply to backhaul radio links. To 

apply the diffraction results to access links, an additional 

cosine angle dependence should be included [12] to account for 

the oblique incidence caused by the height difference. 

 

1) Building Corner: To investigate the path loss for a NLOS 

link in which the RX is shadowed by a building, diffraction 

measurements around two different corners were recorded. 

The geometries of the corners are shown in Fig. 4. The first 

corner considered was composed of concrete. The TX cart was 

placed so that the TX distance from the corner rTX = 3.75 m 

and �’ = 18 degrees. The RX was moved in an arc in the 

shadowed region. The radius of the arc which is the distance 

to the corner rRX = 2.8 m. Measurements were recorded for 

angles � = 200 to 260 degrees at intervals of 10 degrees. 

 

Measurements were also performed on another corner 

shown in Fig. 3.a, composed of concrete with windows located 

near the corner. The TX cart was placed so that rTX = 6.1 m and 

�’ = 10 degrees. The RX was again moved in an arc with 

radius rRX = 4.0 m in the shadow region. Measurements were 

recorded for  � = 200 to 260 degrees at intervals of 15 degrees.  

 

 

Figure 1. Block diagram of 60 GHz measurement setup 

 

  -30

 

  -20

 

  -10

 

  0

 

-60

 

-30

 

0

 

30

 

60

 

90

-90

 

Angle [degrees]

 

Nor

ma

 

lize

d G

 

ain 

[dB]

 

 

 

 

 

H-Plane

E-Plane

 

 

Figure 2. H-Plane and E-Plane normalized antenna gains. 

 

 

 

 

(a) 

 

 

(b) 

 

 

 

 

(c)  

 

 

(d) 

 

Figure 3. (a) Corner 2, (b) Car, (c) Lamppost and (d) Building 

 

 

Figure 4. Diffraction around a building corner. 

 

 

2) Car: Vehicular scattering measurements on a 2006 Subaru 

Forrestor shown in Fig. 3.b, were recorded in an empty 

parking lot. The TX antenna was placed at distance rTX = 23 m 

from the car. The TX antenna bore sight was centered on the 

side of the car and was normal (�i = 0 degrees) to the car’s 

surface. Measurements were recorded as the RX antenna was 

moved in an arc of approximate radius rRX = 23 m, so that the 

scattering angle �s relative to the normal of the car surface, 

spanned 14 to 75 degrees.  

 

12391239

 

 

 

3) Lamp Post: Power measurements on an isolated 3.7 m high 

lampost shown in Fig. 3.c, with a square 0.1 m x 0.1 m cross 

section were performed. The TX antenna was placed at a 

distance rTX = 5 m from the lamppost. Measurements were 

recorded as the RX antenna was moved in an arc of radius rRX 

= 5.5 m around the lampost so that the angle between the 

incident and scattered ray �s spanned 7 to 151 degrees.  

4) Building Surface: To investigate the reflection/scattering of 

features on a building surface, power angle profile 

measurements from a 4-story office building shown in Fig. 

3.d, were performed. The TX and RX antennas were placed so 

that they were separated from each other by 8 m, and were 8.5 

m from the building surface. Using the pan-tilt motors the TX 

antenna illuminated different portions of the building surface. 

For each portion of the building surface, the RX antenna 

illuminated the same surface, so as to measure the received 

power from that surface.  

 

C. Human Blocking Measurements 

Human blocking measurements were performed for mobile 

 

to mobile and access link scenarios. These measurements are 

later compared with predictions found from assuming the 

blockers are absorbing screens and then using UTD and 

physical optics to compute the diffraction loss.  

1) Mobile to Mobile: In mobile to mobile communications the 

TX and RX antennas are typically at the same height or lower 

than normal human height. From [8], the majority of human 

blocking cases involved three blockers at most. Thus, we 

investigated two and three human blocking scenarios of a 7 m 

LOS link. The antenna heights were hTX = hRX = 1 m. A more 

detailed presentation of the setup and results is found in [9]. 

2) Access: For office or outdoor access radio links, the TX 

antennas are typically located on ceilings, light posts, etc., 

above human height. To investigate this radio scenario, one 

human blocking measurements of a 7 m LOS link were 

performed. The antenna heights were hTX = 2.65 m and hRX = 

0.9 m. Measurements were recorded as the human blocker 

moved from the TX toward the RX antenna. During the entire 

experiment, the human blocker’s body faced the RX antenna 

and was centered on the direct line between the TX and RX 

antenna.  

 

For each of the mobile-to-mobile and  access link human 

blocking configurations, five measurements were recorded 

over a 5 second time period. These measurements were then 

time-averaged in an attempt to mitigate the inadverdent 

movement of the human blockers.  

 

III. DIFFRACTION FROM SINGLE AND MULTIPLE EDGES 

A diffracting corner is modeled as a conducting right-angle 

 

wedge and an absorbing screen with a knife-edge in our 

comparison with measurements. Human blockers are modeled 

as semi-infinite absorbing screens with knife-edges. The 

following sub-sections give expressions for the path gain and 

diffraction loss around a conducting wedge, and single and 

multiple absorbing screens. 

 

A. Diffraction Around a Single Edge 

The received power PR in watts from diffraction around a 

 

vertical edge [12] can be expressed in the form  

 

( )

( )

 

22

 

1 2

2

 

1 2 1 2

 

,

4 ( ) cosR T RX TX

 

D r rP P G G

r r r r

 

ϕ ϕλ

π ψ

 

� �′

� � +

 

� �=

 

+

� �

 

 

 �

 

� 

 

.      (1) 

 

Here PT is the transmitted power in watts, and GRX and GTX are 

the antenna gains of the TX and RX antennas, respectively. � is 

the wavelength in meters, � and �’ are the angles in radians 

defined in Fig. 4, �/2 - � is the acute angle the incident wave 

makes with the edge in radians, and D(�, �’) is the diffraction 

coefficient. Note that when � = 0, the incident wave is incident 

normal to the edge. r1 and r2 are the distances of the TX and 

RX antennas to the edge in meters, respectively. The received 

power can be separated into two terms. The first term is the 

LOS power along the diffracted path. The second term in the 

square bracket is the diffraction loss incurred from diffracting 

around the corner.  

 For a semi-infinite absorbing screen with a knife edge 

corner, the UTD expression for D(�, �’) is  

 

( ) 2 1 cos( ) 2 2

2sin( )2

 

S S SD f jg

k

 

π θθ

θ π ππ

 

� �

 

� � � �+

= − +

 

� �

 

� �

 

� �

 

� �

 

 

 � 

 �

 

� 

 

.     (2) 

 

Here � = � + �’ - � as seen in Fig. 4, and f, g, and S are defined 

in [12, chapter 5].  

 For a conducting right angle wedge corner with E-field 

parallel to the edge, the geometric theory of diffraction (GTD) 

diffraction coefficient is expressed as 

 

( ) 1 ( ) ( ), cot cot

3 33 2

 

( ) ( )                          cot cot

3 3

 

D

k

 

π ϕ ϕ π ϕ ϕϕ ϕ

π

 

π ϕ ϕ π ϕ ϕ

 

′ ′

− � + − + +

 

� � � �

 

′ = +

� �

 

 

 

 � 

 �

 

 

′ ′

− − − + �

 

� � � �

 

− −

 

� �

 

 

 

 � 

 �

 

 

 

.(3) 

 

B. Diffraction Around Multiple Absorbing Screens 

To compute the diffraction loss, defined as free-space 

 

power to diffracted power, from an arbitrary number of screens 

parallel to the y = 0 plane, we use a physical optics method 

developed by Piazzi [12]-[14]. This method is based on the 

same principles of physical optics used in [15].  

 

Assuming a) the knife-edges are of infinite length and are 

parallel, and b) the additional diffraction loss for a point source 

on a plane that is perpendicular to the screens is the same as 

that for a line source that is parallel to the screens and 

intersects the plane at the source point, the physical optics 

description of diffraction around an absorbing screen is 

expressed as multiple integrations in the x–z planes containing 

the absorbing screens. The integrations in the coordinate along 

a z-plane knife-edge can be approximated analytically so that 

we are left with integration in the x-coordinate away from the 

knife-edges. This is seen in the following expression for the 

magnetic field H(xn+1, yn+1) in the plane containing the n + 1 

absorbing screen [13]:  

 

12401240

 

 

 

 ( ) ( )/ 41 1, ,2

jk

 

j

n n n n n

 

k eH x y e H x y dx

ρ

 

π

 

π ρ

 

 

+ +

 

−∞

 

=

 

.   (4) 

 

Here � is the distance from the secondary source point (xn, yn) 

on plane x = xn to receiver point (xn+1, yn+1) on plane x = xn+1, 

and k is the free-space wave number. The field on plane x = xn 

containing the nth screen is given by H(xn, yn). To arrive at an 

expression with multiple integrals, we substitute H(xn, yn) in (4) 

with H(xn-1, yn-1), which is the field on plane x = xn-1 containing 

the n - 1 screen and can similarly be written in integral form.  

 

To predict the diffracted power from multiple screens, the 

integrals must be carried out numerically. The integral in (4) 

must be terminated with finite upper and lower limits (for the 

right and left sides of the screen), and the integration must be 

replaced by a discrete summation. The Piazzi method involves 

simple linear approximations of the amplitude and phase and 

introduces a smoothing procedure that uses a Kaiser-Bessel 

function to terminate the integration without introducing 

spurious diffraction [12]–[14]. 

 

IV. RESULTS AND ANALYSIS 

The recorded measurements are presented and compared 

 

with theoretical models in this section.  

 

A. Building Corner Diffraction 

The magnitude of the diffraction coefficient values are 

 

computed from building corner measurements using (1), and 

are plotted in dB versus � = � + �’ - � in Fig. 5. Also plotted 

are the UTD absorbing screen diffraction coefficient (2) and 

the conducting GTD right-angle wedge diffraction coefficients 

(3) for �’ = 10 and 18 degrees. As seen in Fig. 5, the 

conducting wedge gives a pessimistic prediction to the 

diffraction coefficient, while the absorbing screen gives a more 

reasonable prediction. To quantify the accuracy we define the 

error as the predicted diffraction coefficient magnitude in dB 

minus the measured. The absorbing screen diffraction 

coefficient for �’ = 10 and 18 degrees gives mean errors of -1 

and 2.79 dB, respectively. The standard deviations of error are 

1.56 and 2.6 dB respectively. 

   

 

-70 -60 -50 -40 -30 -20 -10 0

-60

 

-50

 

-40

 

-30

 

-20

 

-10

 

0

 

Di

ffr

 

ac

tio

 

Co

 

ef

fic

 

ie

n

 

t |D

( θ)

 

| [d

B]

 

θ [deg]

 

 

 

 

Corner 1 Measurements φ' = 18 degrees

Corner 2 Measurements φ' = 10 degrees

Abosrbing Screen

Conducting Wedge φ' = 18 degrees

Conducting Wedge φ' = 10 degrees

 

 

Figure 5. Comparison of diffraction coefficient measurements 

and theoretical diffraction coefficients. 

 

0 20 40 60 80 100 120 140 160

10

 

15

 

20

 

25

 

30

 

35

 

40

 

Sc

a

 

tte

rin

 

Lo

 

ss

 

 

[dB

]

 

Scattering Angle θs, ψs [degrees]

 

 

 

 

Car

Lamppost

 

 

Figure 6. Scattering loss from a car with incident angle �i = 0 

degrees, and lamppost.  

 

 From [16], the structure of a diffracting corner has a 

significant impact on the diffraction coefficient of the corner. 

For example, rays traveling through the windows near to a 

corner may have a larger contribution to the received power 

than those diffracted by the corner. In our measurements, we 

did not see this effect probably because the metal blinds of the 

windows near the corner shown in Fig. 3.c were drawn down.  

 

B. Scattering from Car and Lampost 

The scattering losses from a car (blue triangles) are plotted 

 

versus scattering angle �s in Fig. 6. The scattering loss is the 

received power normalized to the free space power over the 

scattering path length rTX + rRX. As expected, the scattering loss 

is smaller nearer to the specular direction �s = 0 degrees.  

 The scattering losses from a lamppost (red squares) are 

plotted versus the scattering angle �s between the incident and 

reflected waves in Fig. 6. Again, the scattering loss is the 

received power normalized to the free space power over the 

scattering path length rTX + rRX. The low loss at 144 degrees on 

the lamppost curve corresponds to specular reflection from the 

lamppost’s rectangular cross section.  

 

C. Building Shadowing; Diffraction vs. Scattering 

It is interesting to compare the contributions from scattered 

 

rays and diffracted rays for the case of a NLOS mmW link in 

which the TX and RX are located on the sidewalks of adjacent 

sides of a building, and rTX = rRX = 23m from the corner. The 

diffraction angle � is then close to -90 degrees, so that the 

absorbing screen diffraction coefficient magnitude is 

approximately 40 dB. Accounting for the distance dependence, 

the diffraction loss (square brackets of (1)) is then 

approximately 50 dB. Now assume there is a car near the 

corner and the car is parked parallel to the building surface. 

Using our measurements from Fig. 6, the scattering loss is then 

on the order of 30 dB.  For this case the vehicular scattering 

gives a much larger contribution than the corner diffraction. 

 

Now consider a similar case, but with a square cross-

section lamppost near the corner instead of a car and the RX 

and TX distances to the corner and lamppost are rTX = 5 m and 

rRX = 5.5 m, respectively.  The diffraction loss for the corner is 

44 dB, while the scattering loss from Fig. 6, will be less than 

40 dB. Depending on how the lamppost is oriented, the 

 

12411241

 

 

 

scattering loss can be on the order of 12 dB. Thus, for this 

scenario, the contribution from the lamppost is expected to be 

dominant.   

 

To extend these results to more general radio scenarios, we 

would have to know the distance dependence of the received 

power from the car and lamppost. Though, if we assume they 

have similar distance dependence to corner diffraction, we can 

conclude that the scattering will usually be dominant for the 

short TX-RX separations under consideration. 

 

D. Building Scattering 

The received power angular profile minus the LOS power 

 

in dBm at the RX antenna is plotted in Fig. 7. It can be seen 

that the majority of power arrives in the horizontal plane 

(elevation angle = 0 degrees) containing the TX and RX 

antennas at 0, 25 and 40 degrees. The 0 and 40 degree humps 

correspond to columns on the building surface, while the 25 

degree hump corresponds to specular reflection. Other humps 

outside this plane correspond to window sills and a triangular 

prism feature on the building surface. Other results not shown 

give similar results. These 60 GHz results are similar to UHF 

band results presented in [17] and [18], where the features on 

the building surface (e.g., balconies and columns) contributed 

significantly to the received power angle profile.  

 

E. Mobile to Mobile Link Human Blocking 

In our measurements, the transmission loss through a single 

 

blocker is greater than 50 dB, and reflection and scattering 

from nearby objects are heavily attenuated by the TX and RX 

antenna patterns. Therefore, the blocking loss, defined as the 

power ratio between the unobstructed to the obstructed 

received power, is essentially the diffraction loss around the 

blockers. In this sub-section, our mobile-to-mobile human 

blocking loss measurements are compared with diffraction loss 

predictions found using the Piazzi method described in Section 

III.B for human blockers modeled as semi-infinite absorbing 

screens of infinite height similar to [8], [19]. 

 

Fig. 8 shows the time-averaged blocking loss 

measurements for different two and three-person blocking 

configurations in increasing order of blocking loss. The 

predicted blocking losses from the Piazzi method are also 

plotted. Depending on the configuration of the blockers, there 

can be deep fades in the measurements where the blocking loss 

is greater than 30 dB. The blocking loss in all scenarios ranges 

from -2.7 dB to 43.5 dB. This range is much larger than those 

presented in [8] and [10] and further justifies the need to 

include human blocking models in 60 GHz channel simulators. 

Fig. 8 also shows the errors in the predictions made using the 

Piazzi method for the different blocking configurations. 

Prediction error is defined as the predicted blocking loss minus 

the time-averaged blocking loss. The mean and standard 

deviations of the prediction error are -1 dB and 5.2 dB, 

respectively. 70% of the configurations had prediction error  

between ±5 dB. The majority of configurations with high 

blocking loss typically have large positive prediction errors. 

High blocking loss may be caused by large diffraction angles. 

This suggests that another model, for example, a cylindrical 

model, may better predict diffraction around blockers at large 

diffraction angles. However, from the standard deviation, we 

expect that the absorbing-screen model is sufficient to compute 

blocking loss in most applications.  

 

 

Figure 7. RX antenna received power angular profile relative to 

LOS power with incident angle �i = 25 degrees on building. 

 

0 20 40 60 80 100

-10

 

0

 

10

 

20

 

30

 

40

 

50

 

Bl

oc

 

ki

ng

 

 

Lo

 

ss

 [d

 

B]

 

 

 

 

 

Measurement

Prediction

 

0 20 40 60 80 100

-20

 

0

20

 

|Er

ro

 

r| [

dB

 

]

 

Blocking Configuration

 

 

Figure 8. Comparison of mobile-to-mobile blocking gain 

measurements to Piazzi method predictions. 

 

0 1 2 3 4 5 6

-5

 

0

 

5

 

10

 

15

 

20

 

25

 

30

 

35

 

40

 

45

 

Distance from RX [m]

 

Bl

oc

 

ki

ng

 

 

Lo

 

ss

 

 

[dB

]

 

 

 

 

 

UTD

Measurements

 

 

Figure 9. Comparison of access link blocking loss 

measurements to UTD predictions. 

 

12421242

 

 

 

F. Access Link Human Blocking 

The time-averaged blocking loss measurements as a human 

 

blocker walks toward the elevated TX antenna and away from 

the RX antenna is plotted in Fig. 8 versus the distance x from 

the TX antenna. To predict the blocking loss, the contributions 

from transmission through the humans, and scattering and 

reflection from nearby objects are again heavily attenuated, so 

that the blocking loss is the diffraction loss. Similar to the 

mobile-to-mobile case, two rays diffracting around the sides of 

the human blocker were considered. Unlike the mobile-to-

mobile case, the absorbing screen modeling the blocker has 

finite height, because the antennas are no longer low relative to 

the blocker height. The predicted diffraction loss using the 

human blocker’s actual width of 0.43 m and an effective height 

of 1.61 m for the absorbing screen is also plotted in Fig. 9. This 

effective height value was chosen so that mean prediction error 

was approximately 0 dB, which corresponded to a standard 

deviation of 3.2 dB.  

 Note that the actual height of the blocker is 1.72 m with a 

head height of 0.25 m. From this and other access link blocking 

measurements, we found that decreasing the blocker’s head 

height by 35% to 45% gave the best prediction.  

 

V. CONCLUSION 

In this work, 60 GHz measurements of corner diffraction, 

 

scattering from a car, lamppost and building, and human 

blocking are presented. The absorbing screen diffraction model 

is found to give good comparison with diffraction 

measurements. Scattering measurements from cars and 

lampposts are found to peak near the specular direction. For 

building shadowed mmW links, comparisons of the scattering 

measurements with the absorbing screen diffraction model 

suggests that the scattering from cars and lampposts is 

dominant compared to corner diffraction. This indicates the 

need to include scattering models of common urban furniture 

in millimeter wave propagation simulators. 

 

The building scattering measurements show that the 

majority of received power arrives in the horizontal plane 

containing the TX and RX and peaks in the specular direction. 

Non-specular contributions were found to originate from 

features on the wall, such as ridges and columns. Based on this 

result, we suggest utilizing a horizontal plane assumption in 

smart beam-finding algorithms when searching for building 

scattered paths to decrease complexity and acquisition time.  

 

To account for human blocking in mmW propagation 

simulators, several models were previously proposed in the 

literature. In this work, we focused on the absorbing screen 

model and proposed the use of an effective human height for 

the screen height rather than the actual human height. 

Validation of this absorbing screen model was performed using 

human blocking measurements of single and multiple human 

blockers of mobile-to-mobile and access links. Results show 

that the absorbing screen model is quite accurate with standard 

deviation of prediction error less than 5 dB.  

 

 

 

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