Millimeter Wave Mobile Broadband: Unleashing 3-300 GHz Spectrum

Millimeter-wave Mobile Broadband:
Unleashing 3-300GHz Spectrum
Farooq Khan & Jerry Pi
Samsung
March 28, 2011
1Copyright © 2011 by the authors. All rights reserved.

Outline
• Introduction
– Mobile broadband growth
– The myth of traffic and revenue gap
– The national broadband plan
• mmW spectrum
– History of millimeter wave communications
– Unleashing 3-300GHz spectrum
– LMDS and 70/80/90 GHz bands
• mmW Propagation characteristics
– Free Space Propagation
• MMB air-interface design
– Duplex and multiple access schemes
– Frame Structure
– Channel coding and modulation
• Dynamic beamforming with miniature antennas
– Beamforming fundamentals
– Baseband beamforming
– Analog beamforming
– RF beamforming
– Beamforming in fading channels– Free Space Propagation
– Material penetration loss
– Oxygen and water absorption
– Foliage absorption
– Rain absorption
– Diffraction
– Ground reflection
• mmW Mobile Broadband (MMB) network
architecture
– Stand-alone MMB system
– MMB base station grid
– Hybrid MMB + 4G systems
– Deployment and antenna configuration
– Beamforming in fading channels
• Radio frequency components design and
challenges
– RF transceiver architecture
– MMB RF transceiver requirement
– mmWave Power amplifier
– mmWave LNA
• MMB system performance
– Link budget analysis
– Link Level performance
– Geometry distribution
– System throughput analysis
• Summary

Outline
• Introduction
• mmW spectrum
– Frame Structure
– RF beamforming
– Rain absorption
– Diffraction
architecture
challenges
– mmWave LNA
• Summary

Mobile Subscriber Growth
30
40
50
60
70
80
90
100
Per100inhabitants
Global ICT developments, 2000-2010*
Mobile cellular telephone subscriptions
Internet users
Fixedtelephone lines
Mobile broadband subscriptions
Fixedbroadband subscriptions
Year 2010
• 6.9 billion world population
• 5.3 billion mobile users
• 2.1 billion Internet users
• 940 million mobile broadband users
0
10
20
30
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010*
*Estimates
Source: ITU World Telecommunication /ICT Indicators database
4

Mobile Internet traffic pushes the limit of
mobile broadband networks …
5

The exciting (and yet concerning) future
A much larger (and growing)
portion of the IP traffic to
become mobile
6

The myth of mobile data traffic revenue gap
1000
1500
2000
2500
3000
3000
4000
5000
6000
7000
8000
mobiledatarevenue($B/yr)
Mobiledatatraffic(PB/mo)
2000
3000
4000
5000
6000
400
600
800
1000
1200
1400
Computerpriceindex
CPUgatecount(millions)
The yawning gap between
mobile data traffic and revenue
But, we have seen
this before …
0
500
1000
0
1000
2000
3000
2010 2011 2012 2013 2014 2015 mobiledatarevenue($B/yr)
Mobile data traffic Mobile data revenue
0
1000
0
200
400
2000 2002 2004 2006 2008 2010
Computerpriceindex
CPU gate count Computer price index
Expon. (CPU gate count)
Also available in many other occasions:
•Transistor counts per IC – Moore’s Law
•The hard disk storage – Kryder’s Law
•Network capacity – Butter’s Law of Photonics, Nielsen’s Law
•The Great Moore’s Law Compensator – Wirth’s Law

1000
1000
10000
100
1000
100
1000
10000
Computerpriceindex
Looking from another perspective, our gap seems to be actually quite small, if any
The myth of mobile data traffic revenue gap
100100
2010 2011 2012 2013 2014 2015
Mobile data traffic Mobile data revenue
1010
2000 2002 2004 2006 2008 2010
CPU gate count Computer price index
Expon. (CPU gate count)
The moral of the story
• Your eyes may fool you
• “Yawning gap” already exists in many (yet thriving) ICT industries
• If there is a gap between mobile data traffic and revenue, get used to it.
Need technology to provide >100x capacity with similar cost as cellular

US Frequency Allocation Chart
9

National Broadband Plan
Part of the American Recovery and Reinvestment Act passed in February 2009
Published on March 15, 2010
Ambitious goals
•Goal 1: At least 100 million U.S. homes should have affordable access to actual download speeds of
at least 100 megabits per second and actual upload speeds of at least 50 megabits per second.
•Goal 2: The United States should lead the world in mobile innovation, with the fastest and most
extensive wireless networks of any nation.
•Goal 3: Every American should have affordable access to robust broadband service, and the means
and skills to subscribe if they so choose.
•Goal 4: Every community should have affordable access to at least 1 Gbps broadband service to
anchor institutions such as schools, hospitals and government buildings.
•Goal 5: To ensure the safety of Americans, every first responder should have access to a nationwide
public safety wireless network.
•Goal 6: To ensure that America leads in the clean energy economy, every American should be able
to use broadband to track and manage their real-time energy consumption.

The gist of NBP - 500MHz more spectrum
Make 500 megahertz of spectrum newly available for
broadband within 10 years
300 megahertz (between 225MHz and 3.7GHz) should be made
available for mobile use within five years
• 20 MHz of Wireless Communications Spectrum (WCS) in the 2.3GHz range• 20 MHz of Wireless Communications Spectrum (WCS) in the 2.3GHz range
• 10 MHz D Block of 700MHz band re-auction for "commercial use” that is
compatible with public safety services
• 60 MHz of Advanced Wireless Spectrum (AWS) in the 1900MHz and 2000MHz
range
• 90 MHz of Mobile Satellite Spectrum to be used for terrestrial purposes in
regions where it is difficult to deploy cellular
• 120 MHz of reallocated TV broadcast spectrum (TV broadcasters are rallying
against it)

Outline
• Introduction
• mmW spectrum
– Frame Structure
– RF beamforming
– Rain absorption
– Diffraction
architecture
challenges
– mmWave LNA
• Summary

Wave
propagation
Eletric field
Magnetic field
The Electromagnetic Waves
A changing electric field
generates an oscillating
magnetic field
A changing magnetic field
generates another changing
electric field
These oscillating fields forms
electromagnetic waves that
λλλλ
electromagnetic waves that
propagates at speed of light

What is Millimeter-wave?
Micro-wave
•Frequency 300 MHz ~ 300 GHz (Wavelength 1mm ~ 1m)
Millimeter-wave (the high-end of the micro-wave frequencies)
•Frequency 30 GHz ~ 300GHz (Wavelength 1mm ~ 1cm)
•In this tutorial, we refer to frequencies between 3GHz and 300GHz as millimeter-wave in our effort to
explore new spectrum for mobile broadband communication
Current applications of millimeter-wave
•Radio astronomy, wireless backhaul, inter-satellite link, high resolution radar, security screening,
amateur radio

The History of Millimeter-wave
1864 :
• The existence of electromagnetic waves was predicted by James Clerk Maxwell from his equations.
1888:
• Heinrich Hertz was the first to demonstrate the existence of electromagnetic waves by building an
apparatus that produced and detected microwaves in the UHF region. The design necessarily used
horse-and-buggy materials, including a horse trough, a wrought iron point spark, Leyden jars, and a
length of zinc gutter whose parabolic cross-section worked as a reflection antenna.1888: length of zinc gutter whose parabolic cross-section worked as a reflection antenna.
1894:
• J. C. Bose publicly demonstrated radio control of a bell using millimeter wavelengths, and conducted
research into the propagation of microwaves.
1931:
• the first, documented, formal use of the term microwave: "When trials with wavelengths as low as
18 cm were made known, there was undisguised surprise that the problem of the micro-wave had
been solved so soon." Telegraph & Telephone Journal XVII. 179/1

Unleashing the 3-300GHz Spectrum
With a reasonable assumption that about 40% of the spectrum in the
mmW bands can be made available over time, we open the door for
possible 100GHz new spectrum for mobile broadband
• More than 200 times the spectrum currently allocated for this purpose below 3GHz.

LMDS and 30/40 GHz bands
A total of 1.3GHz spectrum available in the LMDS bands
Possibly, a total of 3.4GHz spectrum available in the 38GHz (38.6–40GHz) and 40GHz
(40.5-42.5) bands

70/80/90 GHz (E-band)
A total of 12.9GHz bandwidth available in the E-band

Spectrum Identified for MMB
Band Frequency range
[GHz]
Available Spectrum [GHz]
23GHz 22.55-23.55 1.0
LMDS
27.50-28.35,
29.10-29.25,
31.075-31.225
1.3
38GHz 38.6-40.0 1.4
40GHz 40.50-42.50 2.040GHz 40.50-42.50 2.0
46GHz 45.5-46.9 1.4
47GHz 47.2-48.2 1.0
49GHz 48.2-50.2 2.0
E-band
71-76
81-86
92-95
12.9
Others --
Total 23.0

Outline
• Introduction
• mmW spectrum
– Frame Structure
– RF beamforming
– Rain absorption
– Diffraction
architecture
challenges
– mmWave LNA
• Summary

Propagation Loss
Transmission loss of mmW is accounted for principally by the free space loss
Free-space loss (Isotropic antennas)
• LFSL, dB = 92.4 + 20logf + 20logR
• f is the carrier frequency in GHz• f is the carrier frequency in GHz
• R is distance in km
Other factors
• Atmosphere Gaseous Losses
• Precipitation attenuation
• Foliage blockage
• Scattering
• Bending

Solid Angle
2
Area r=
rr
r
• One radian is defined as the plane
angle with its vertex at the center of
a circle of radius r that is subtended
by an arc of length r
• 2π radians in a full circle
• One square radian (or steradian) is
defined as the solid angle with its
vertex at the center of a sphere of
radius r that is subtended by a
spherical surface of area r2
• 4π steradians in a closed sphere
Copyright © 2011 by the authors. All rights reserved. 22
2
4A rπ=2C rπ=

Beam Area (or Beam Solid Angle) [1/2]
z
0θ =
θ
θ
sin
r
θ
sinr dθ φ
rdθ 2
sindA r d dθ θ φ=
θ
x
y
φ
0φ =
φ
dφ
r
rdφ
θ
dθ
2
( )( sin )
sin
dA rd r d r d
d d d
θ θ φ
θ θ φ
= = Ω
Ω =
Where Solid Angle subtended by the areadΩ = dA

Beam Area (or Beam Solid Angle) [2/2]
• The beam area (or beam solid angle) of an antenna is given by the integral
of the normalized power pattern over a sphere:
( )
( )
2
0 0
, sin
,
A nP d d
P d
φ π θ π
φ θ
θ φ θ θ φ
θ φ
= =
= =
Ω =
Ω = Ω
∫ ∫
∫∫
2
sin 4d d
φ π θ π
θ θ φ π
= = 
= 
  
∫ ∫
• The beam area is the solid angle through which all of the power radiated
by the antenna would stream if P(θ, φ) maintained its maximum value
over ΩΑ and was zero elsewhere.
( )
4
,A nP d
π
θ φΩ = Ω∫∫ 0 0φ θ= =  
∫ ∫
Power radiated = ( , ) AP θ φ Ω

Directivity and Gain of an Antenna
( )
( )
( )
( )
( ) ( )
max
max
2
0 0
max max
,
,
,
1
, sin
4
, ,
av
P
D
P
P
D
P d d
P P
D
φ π θ π
φ θ
θ φ
θ φ
θ φ
θ φ θ θ φ
π
θ φ θ φ
= =
= =
=
=
= =
∫ ∫
( )
( )
( )
( )
( )
( )
( )
max max
4 4
4
4 max
, ,
1 1
, ,
4 4
4 4 4
,,
,
An
P P
D
P d P d
D
P dP
d
P
π π
π
π
θ φ θ φ
θ φ θ φ
π π
π π π
θ φθ φ
θ φ
= =
   
Ω Ω   
   
= = =
Ω  Ω
Ω 
  
∫∫ ∫∫
∫∫
∫∫
( )
Antenna Gain
where k= efficiency factor 0
Gain is less than directivity due to ohmic losses in the antenna
G kD k= ≤ ≤

Antenna Aperture
AΩ
aE rE
eA r
2
a e
r
a
E A
E
r
E
P A
λ
=
=
4
A
D
π
=
Ω
0
2
2
0
2 2
2
0 0
2 2 2
2
2 2
0 0
2
a
e
r
A
a r
e A
a a e
e A
A
e
E
P A
Z
E
P r
Z
E E
A r
Z Z
E E A
A r
Z r Z
A
λ
λ
=
= Ω
= Ω
= Ω
Ω =
2
2
2
4
4
4
A
A
A
e
e
e
D
A
D A
A
D
π
λ
π λ
π
λ
Ω
Ω =
Ω =
=
=
2
2
4
1 Isotropic Antenna
4
e
e
A
D
A
π
λ
λ
π
= =
=

Pathloss with Isotropic Antennas
2
2
2
Area of receive antenna
of a sphere 4
Area of an ideal isotropic antenna,
4
Formula,
4
r r
t
r
r
P A
P Area r
A
P
Friis
P r
π
λ
π
λ
π
= =
=
 
⇒ =  
 
rA
r
2
4A rπ=
4tP rπ 
 
• For isotropic antennas, path loss increases with frequency

Pathloss with directional antennas
4 effeff eff
AP A Aπ 
eff
tA eff
rA
tP rPt tPG
2 2 2
2 2
4
4 4
1
effeff eff
tr r r
t
t
eff eff
t rr
t
AP A A
G
P r r
A AP
P r
π
π λ π
λ
 
= =  
 
= ⋅
• Receive power improves with frequency!!
• 31.5 dB more gain at 90GHz compared to 2.4GHz if antenna size is kept
constant

Foliage Losses
At 80GHz frequency and 10 meters
foliage penetration, the loss can be
about 23.5dB which is about 15dB
higher compared to the loss at 3GHz
frequency.
Foliage losses for millimeter waves
are significant and can be a limiting
impairment for propagation in some
cases.
( ) ( )
0.3 0.6
5
fol
f D
L =

Rain Attenuations
Light rain at a rate of 2.5mm/hour yields just
over 1 dB/km attenuation while heavy rain
at the rate of 25 mm/hour can result in over
10 dB/km attenuation at E-band (70/80/90
GHz) frequencies
More severe rain such as Monsoon at a rate
of 150mm/hour can jeopardize
communications with up to tens of dBs of
loss per km at millimeter wave frequencies.
Therefore, a mechanism such as supporting
emergency communications over cellular
bands when mmW communications are
disrupted by heavy rains should be
considered as part of the MMB system
design.

Attenuations for different materials
Attenuation [dB]
Material
Thickness
[cm]
2.5GHz
[7]
40GHz
[8]
60GHz [7]
Drywall 2.5 5.4 - 6.0
Office Whiteboard 1.9 0.5 - 9.6
Clear Glass 0.3/ 0.4 6.4 2.5 3.6
Mesh Glass 0.3 7.7 - 10.2
Chipwood 1.6 - 8.6 -
Wood 0.7 - 3.5 -
Plasterboard 1.5 - 2.9 -
Mortar 10 - 160 -
Brick wall 10 - 178 -
Concrete 10 - 175 -

Diffraction (Fresnel Zones)
1 2
1 2
n
n d d
r
d d
λ
=
+
Higher frequencies have smaller Fresnel
zone radii and hence can pass through
narrow gaps with lower loss

Ground Reflection [1/3]
( ) ( )
2 22 2
2 1
2 2
2 2
1 1
21 1
1 1
2 2
t r t r
t r t r
t r t r t r
d d h h d h h d
h h h h
d
d d
h h h h h h
d
d d d
∆ = − = + + − − +
 + −    ∆ = + − +   
    
 
 + −   
∆ ≈ + − + =         
22
,
2
t r
d
c
h h
d c f
π θπ
θ τ
λ λ π
∆
∆
∆ ∆
= = = =
The “Free-space” path loss exponent at
mmW frequencies is likely going to be
smaller than the lower RF frequencies
for coverage distances of interest

The field strength can be calculated by adding
the direct and reflected ray accounting for
phase differenceθ∆
( )
( )
( )
( ) ( )( )
2
2
2
1
1
1 1
1 cos sin
j
T i
j
j
E E e
P e
P e
P j
θ
θ
θ
ρ
ρ
ρ
θ θ
∆
∆
∆
−
−
−
= +
∝ +
∝ − = −
∝ − +
For grazing incidence ρ = -1
( ) ( )( )
( ) ( )
( )
( )
2
2 2
2
2
2
2 2 2
2 2 2
1 cos sin
1 cos sin
1 cos
4 sin
2
4 sin 4sin cos
2 2 2
4sin sin cos
2 2 2
P j
P
P
P
P
θ θ
θ θ
θ
θ
θ θ θ
θ θ θ
∆ ∆
∆ ∆
∆
∆
∆ ∆ ∆
∆ ∆ ∆
∝ − +
 ∝ − + 
 −
∝ + 
 
      
∝ +      
      
      
∝ +     
      
2
4sin
2
P
θ∆

 
∝  
  34Copyright © 2011 by the authors. All rights reserved.

Outline
• Introduction
• mmW spectrum
– Frame Structure
– RF beamforming
– Rain absorption
– Diffraction
architecture
challenges
– mmWave LNA
• Summary

MMB Network
Packet Data Server
Gateway #1
F
G
K
L
Cell Site 2
Cell Site 3
Cell Site 4
MS3
MS2
TX/RX
R
X/TX
TX
High-gain Tx/Rx
beamforming
• significantly suppress
other-cell
interference and
• creates overlapping
Packet Data Server
Gateway #2
B
C
DE
A
H
I
J
K
Cell Site 1
Cell Site 5
Cell Site 6
Cell Site 7
MS1
MS2
TX/RX
RX/TX
• creates overlapping
coverage of MMB
base stations
mmW in-band
inter-base station
backhauling
• enable deployment
without fixed-line
high-speed backhaul

An interference limited cellular network
Clear cell boundaries and
cellular footprint for each cell
due to inter-cell interference
Many base stations are notMany base stations are not
visible to mobile station due to
strong interference from a few
dominant serving/interfering
base stations
Mobile station only
communicate with one serving
cell (or few serving cells) at a
time (All other cells generate
interference that works against
the communication)

An MMB base station grid
Inter-cell interference
significantly suppressed
due to strong Tx/Rx
beamforming (Large spatial
multiplexing capability)
Base stations are visible toBase stations are visible to
the mobile station as long
as link budget permits
Large overlap of base
station coverage area (No
clear cell boundary)

SINR comparison
An interference limited cellular network
2
2
0
ik i
ik
jk j
j i
h P
N h P
ρ
≠
=
+ ∑
2
0jk j
j i
h P N
≠
>>∑
Copyright © 2011 by the authors. All rights reserved. 40
An MMB network
( ) ( )
( ) ( )
2
2
0
ik i i ik k ik
ik
jk j j jk k jk
j i
h P
N h P
α θ β φ
ρ
α θ β φ
≠
⋅ ⋅
=
+ ⋅ ⋅∑
Serving cell TxBF
enhances signal strength
RxBF enhances
signal strength
RxBF suppresses
interferences
Other cells TxBF increases interference variation
Increased channel capacity

MMB Overlay on Cellular
Users are served by MMB
opportunistically
Fall back to cellular when mmWave
channel conditions are not suitable
Achieved via dual-mode MMB and 4GAchieved via dual-mode MMB and 4G
deployment
•Separate MMB and 4G systems share cell sites
•Inter-RAT handover to achieve fallback
Or heterogeneous MMB+4G networks
•MMB integrated into existing 4G system (e.g., as
an extension carrier)
•Users are dynamically scheduled in the MMB
carriers when suitable

Heterogeneous MMB+4G Networks
Packet Data Server
Gateway
MS1
MBS_0
MBS_1 MBS_2
MBS_3
MBS_4
MBS_5 MBS_6
CBS_A
CBS B
MS2
MS3
MBS_9
MBS_7
MBS_8
MBS_10
MBS_11
MBS_12
MBS_13
MBS_14
Cellular Base Station (CBS)
MMB Base Station (MBS)
MMB communication link
cellular communication link
CBS_B
CBS_C
Fixed line between MBS and CBS
Fixed line between CBS / MBS and
Packet Data Server / Gateway
MS4

MMB In-band Dynamic Backhauling
Packet Data Server
Gateway
MS2
BS_A
mmWave Link 1
mmW
Beam
1
Beam
0
Beam5
Base stations are connected
via mmWave link
Dynamic beamforming
enables dynamic
backhauling via multiple
MS1
MS3
Cellular Base Station
mmWave communication link
cellular communication link
BS_B
BS_C
Fixed line between BS and Packet
Data Server / Gateway
mmWave Link 2
WaveLink3
Beam
2
Beam
3
Beam4
backhauling via multiple
routes
•Increased throughput
•Congestion mitigation
•Improved robustness
Backhaul link and access
link share the same
mmWave band
•Maximize spectrum utilization
•Minimize infrastructure cost

MMB Deployment Scenario
Carrier frequency
• Can be deployed between 3GHz and 300GHz
• Achievable transmission power and efficiency decrease as carrier frequencies
increase (limited by existing mmWave integrated circuit technology)
Deployment scenariosDeployment scenarios
• Urban Macro (Site-to-site distance 1km – 5km, BS Tx Power ~ 50dBm)
• Urban Micro (Site-to-site distance 200m – 1km, BS Tx Power ~40dBm)
• Urban Pico (Site-to-site distance 50m – 200m, BS Tx Power ~30dBm)
• Femto (Site-to-site distance < 50m, BS Tx Power ~20dBm)
Mobility
• Support mobility up to 350kmph for carrier frequencies between 3GHz and 30GHz
• Support mobility up to 120kmph for carrier frequencies between 30GHz and 90GHz

Antenna Configurations
Base station antenna configurations
• 12 horn antennas per cell with each horn
covers 30o field of view
• 17 – 23 dB antenna gain
• 6 antenna arrays per cell with each array
Base station horn antenna
• 6 antenna arrays per cell with each array
covers 60o field of view
• 64 – 1024 antenna elements for each array
Mobile station antenna configurations
• Antenna arrays with 4 – 64 antenna elements
each
Mobile station phase antenna array
Base station phase antenna array

Base Station with Horn Antennas
12 horn antennas per base
station
Each horn antenna serves one
mobile station at a time
Mobile stations perform
antenna selection
Mobile stations employ multi-
antenna array
Mobile stations perform Tx and
Rx beamforming

Base Station with Horn Antennas
17dB Tx
Antenna Gain
~12dB Rx
Antenna Gain
MMB Sector
Antenna Gain
16 Elements (4x4) array
2cm
Horn antennas at base station
Antenna array at mobile station
Mobile station Tx beamforming for uplink
Mobile station Rx beamforming for downlink
( )
( )
2
2
0
ik i k ik
ik
jk j k jk
j i
h P
N h P
β φ
ρ
β φ
≠
⋅
=
+ ⋅∑
Downlink SINR

Base Station with Antenna Arrays
Antenna Arrays arranged in a hexagon structure
with each array covering 600
Each antenna array can serve multiple mobile
stations at a time
Mobile stations perform antenna array selection
Dynamic joint Tx-Rx beamforming with narrow
beams within each sector

Base Station with Antenna Arrays
Antenna array at base station
Antenna array at mobile station
MS TxBF and BS RxBF for uplink
MS RxBF and BS TxBF for downlink
Downlink SINR
( ) ( )
( ) ( )
2
2
0
ik i i ik k ik
ik
jk j j jk k jk
j i
h P
N h P
α θ β φ
ρ
α θ β φ
≠
⋅ ⋅
=
+ ⋅ ⋅∑

Outline
• Introduction
• mmW spectrum
– Frame Structure
– RF beamforming
– Rain absorption
– Diffraction
architecture
challenges
– mmWave LNA
• Summary

Duplex schemes
FDD (Frequency Division Duplex)
• Requires DL and UL carriers (DL and UL can have different bandwidth)
• Good coverage and link throughput
• More RF/mmW hardware (separate antennas/arrays or frequency duplexers/filters)
higher cost
TDD (Time Division Duplex)
• DL and UL transmissions occur in the same carrier but in different time slots• DL and UL transmissions occur in the same carrier but in different time slots
• Tradeoff between downlink and uplink (in terms of both coverage and throughput)
• Less RF/mmW hardware (DL and UL share antennas/arrays) lower cost
• For MMB, the delay performance is expected to be comparable to FDD because of the short
slot duration (125 us)
SDD (Spatial Division Duplex)
• DL and UL transmissions (to and from different mobile stations) occur in the same time-
frequency resources but in different beams
• Require separation of Tx/Rx circuits at the base station
• SDD from the base station point of view
• TDD from the mobile station point of view

Spatial Division Duplex
Tx
R
x
R
x
Base station transmit and receive in
the same time-frequency resource
The transmission and reception are
spatially separated (via Tx and Rx
beamforming)
R
x
beamforming)
Base stations coordinate the
downlink and uplink transmissions
to minimize interferences
Both uplink and downlink channel
state information required at the
base station for proper scheduling
and coordination

Multiple Access
Flexible choice of multiple access schemes
• Supports TDMA, SDMA, OFDMA, and SC-FDMA
• Configurable based on hardware and deployment scenarios
MMB DownlinkMMB Downlink
• TDMA at slot level (OFDM or single-carrier transmission)
• SDMA/OFDMA within a slot
MMB Uplink
• TDMA at slot level
• SDMA/OFDMA/SC-FDMA within a slot

Time-domain Channel Selectivity
3 10 30 60 90
3 8.33 27.78 83.33 166.67 250.00
30 83.33 277.78 833.33 1666.67 2500.00
120 333.33 1111.11 3333.33 6666.67 10000.00
350 972.22 3240.74 9722.22 19444.44 29166.67
3 10 30 60 90
3 120.00 36.00 12.00 6.00 4.00
Doppler
(Hz)
Carrier Frequency (GHz)
Mobile
speed
(kmph)
Coherence Time (ms)
Carrier Frequency (GHz)
Doppler calculated based on worst case scenario
•The direction of velocity aligned with the direction of beamforming
Design choice: MMB to support Doppler up to 10kHz (Coherent time ≥≥≥≥ 100us)
•Different numerology can be developed to support mobility with higher Doppler (e.g., due to
either higher speed or higher frequency)
3 120.00 36.00 12.00 6.00 4.00
30 12.00 3.60 1.20 0.60 0.40
120 3.00 0.90 0.30 0.15 0.10
350 1.03 0.31 0.10 0.05 0.03
Mobile
speed
(kmph)

Frequency-domain Channel Selectivity
Millimeter wave propagation characteristics in a mobile communication
environment is not well understood
• Most literature reports RMS delay ~ 10ns and maximum delay spread ~ 100ns
• For cellular waves in a 1km cell, the maximum delay spread should mostly be within a few
microseconds (1km ~ 3.3us)
• High gain antennas and beamforming of mmW should significantly reduce the delay spread
• As the cell size gets smaller, LOS will occur more frequently, which also reduce the delay• As the cell size gets smaller, LOS will occur more frequently, which also reduce the delay
spread and frequency selectivity
Best guesstimate (at this point) is the maximum delay spread of mmW in a
mobile environment should mostly be less than 1us for cell radius < 1km
• Equivalent to 333-meter difference among the travel distance of the rays that arrive at the
receiver via the narrow beams formed by the transmitter antennas and receiver antennas
Design choice: MMB to support delay spread up to 1us (Coherent bandwidth
≥ 1MHz)

OFDM/Single-Carrier numerology
Subcarrier spacing and Cyclic Prefix
• Two important design parameters that pertain to many issues
• Wide subcarrier spacing leads to sensitivity to frequency selectivity, and high CP overhead
• Narrow subcarrier spacing leads to sensitivity to Doppler, frequency offset, and require more
expensive VCOs and VCXOs
• Larger CP provides protection against inter-symbol-interference due to multipath channel
• Shorter CP incurs less overhead and leads to a more efficient system design• Shorter CP incurs less overhead and leads to a more efficient system design
Subcarrier spacing = 270 kHz
• OFDM/SC symbol length is ~3.7 us
• Possible to support a coherence time of 100 us (350kmph @ 30 GHz, 120kmph @ 90 GHz)
1/8 and 1/4 CP
• Both 1/8 and 1/4 CP are supported
• 1/8 CP = 463 ns, low overhead
• 1/4 CP = 926 ns, ensure good performance in deployment with larger cells (1~5 km)

OFDM/SC numerology (short CP)
Short CP Configurations
System Bandwidth (MHz) 62.5 125 250 500 1000
Sampling rate (MHz) 69.12 138.24 276.48 552.96 1106
Subcarrier spacing (kHz) 270
OFDM symbol length (FFT size) 256 512 1024 2048 4096
OFDM symbol duration (us) 3.70OFDM symbol duration (us) 3.70
CP length 32 64 128 256 512
CP duration (us) 0.46
Slot duration (us) 125
Number of OFDM symbols per slot 30
Subframe duration (ms) 1
Number of slots per subframe 8
Frame duration (ms) 10
Number of subframes per frame 10

OFDM/SC numerology (long CP)
Long CP Configurations
System Bandwidth (MHz) 62.5 125 250 500 1000
Sampling rate (MHz) 69.12 138.24 276.48 552.96 1106
Subcarrier spacing (kHz) 270
OFDM symbol length (FFT size) 256 512 1024 2048 4096
OFDM symbol duration (us) 3.70OFDM symbol duration (us) 3.70
CP length 64 128 256 512 1024
CP duration (us) 0.93
Slot duration (us) 125
Number of OFDM symbols per slot 27
Subframe duration (ms) 1
Number of slots per subframe 8
Frame duration (ms) 10
Number of subframes per frame 10

Frame Structure (Short CP)
CP
CP
CP
CP

Resource Channelization – Subbands
Each subband consists of 4 RBs
• Bandwidth = 4 × 4.86 = 19.44 MHz
• The number of subbands for different system bandwidth
• 3 (62.5 MHz), 6 (125 MHz), 12 (250 MHz), 24 (500 MHz), 48 (1 GHz)
Number of occupied subcarriers
• 216 / 58.6 MHz (for 256-point FFT / 62.5 MHz)
• 432 / 116.9 MHz (for 512-point FFT / 125 MHz)
• 864 / 233.6 MHz (for 1024-point FFT / 250 MHz)
• 1728 / 466.8MHz (for 2048-point FFT / 500 MHz)
• 3456 / 933.4MHz (for 4096-point FFT / 1 GHz)

Resource Channelization – Resource Block
8
9
10
11
12
13
14
15
16
17
Each RB
includes 18
subcarriers
•1 RB = 18 ×
270kHz = 4.86
MHz = 540 REs
•24 symbols used
Time
Freq
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
0
1
2
3
4
5
6
7
8
Control channel RE
Control channel RS
Data channel RE
Data channel RS
•24 symbols used
for data, 1 RB
carries 432 data
REs
•The number of
RBs for different
system bandwidth
•12 (for 62.5MHz)
•24 (for 125MHz)
•48 (for 250MHz)
•96 (for 500MHz)
•192 (for 1GHz)

Channel Coding
Regular protograph LDPC codes
• Highly structured simple decoder design
• High degree of parallelism high throughput
• low decoding complexity low power consumption
• Gbps decoder with power consumption on the order of 100mW• Gbps decoder with power consumption on the order of 100mW
Data channel FEC
• Length-1728 and Length-432 code with code rate (1/2, 5/8, 3/4,13/16)
• Length-1728 codes lifted from the length-432 codes
Control channel FEC
• Length-432 LDPC code with code rate (1/2, 5/8, 3/4,13/16)
• Lower code rates achieved by shortening

LDPC
0 1 0 1 1 1 0 0
1 1 1 0 0 0 1 0
0 0 1 0 0 1 1 1
1 0 0 1 1 0 0 1
H
 
 
 =
 
 
 
1
4, 2,
2
c
r c
r
w
w w r
w
= = = =
Low Density Parity Check codes
• Linear block codes
• Row and column weights << dimension of the parity check matrix
• “Capacity-approaching”
• Iterative decoding with linear decoding complexity (e.g., belief propagation)

HARQ
A combination of FEC and ARQ
Support both incremental redundancy (IR) and chase combining (CC)
Effective in combating fast fading, interference variation, and increasing throughput
Buffer management is critical for effective HARQ in MMB
•1ms buffering = 1M information bits @ 1Gbps, = 16M information bits @ 16Gbps

Modulation and Coding Schemes
MCS Modulation Code rate Repetition Data rate (Mbps) Spectral Efficiency
0 π/2−BPSK 1/2 4 415 0.08
1 π/2−BPSK 1/2 2 829 0.17
2 π/2−BPSK 1/2 1 1659 0.33
3 π/2−BPSK 5/8 1 2074 0.41
4 π/2−BPSK 3/4 1 2488 0.50
5 π/2−BPSK 13/16 1 2696 0.54
6 QPSK 1/2 1 3318 0.66
*Data rate is calculated assuming 5 carriers with 1GHz bandwidth each, 1/8 CP, and 20% control channel overhead
6 QPSK 1/2 1 3318 0.66
7 QPSK 5/8 1 4147 0.83
8 QPSK 3/4 1 4977 1.00
9 QPSK 13/16 1 5391 1.08
10 16QAM 1/2 1 6636 1.33
11 16QAM 5/8 1 8294 1.66
12 64QAM 1/2 1 9953 1.99
13 64QAM 5/8 1 12442 2.49
14 64QAM 3/4 1 14930 2.99
15 64QAM 13/16 1 16174 3.23

Outline
• Introduction
• mmW spectrum
– Frame Structure
– RF beamforming
– Rain absorption
– Diffraction
architecture
challenges
– mmWave LNA
• Summary

MMB Beamforming
The “most critical” technology for MMB
Beamforming Options
• Baseband Digital Beamforming
• Baseband Analog Beamforming (phase shifters)• Baseband Analog Beamforming (phase shifters)
• RF Beamforming (phase shifters)
Challenges
• Beam pattern/codebook design
• Beam training signal/procedure/algorithm design
• Beam tracking signal/procedure/algorithm design
67
Copyright by the authors, all rights reserved

Array of 2 Point Sources [1/3]
θ
r
cos
2
d
θ
cos
2
d
θ
1 2
2 2
cos cos
2 2
0 0
2 2
cos cos
2 2
02
2
d d
j j
d d
j j
E E E
E E e E e
e e
E E
π π
θ θ
λ λ
π π
θ θ
λ λ
−
−
= +
= +
+
=
Same amplitude, same phase
20
0
0
2
2
2 cos cos
2
Assuming 2 1 and / 2
cos cos
2
d
E E
E d
E
π
θ
λ
λ
π
θ
 
=  
 
= =
 
=  
 

θ
r
cos
2
d
θ
cos
2
d
θ
1 2
2 2
cos cos
2 2
0 0
2 2
cos cos
2 2
02
2
d d
j j
d d
j j
E E E
E E e E e
e e
E E
π π
θ θ
λ λ
π π
θ θ
λ λ
−
−
= −
= −
−
=
Same amplitude, opposite phase
20
0
0
2
2
2 sin cos
2
sin cos
2
d
E jE
jE d
E
π
θ
λ
λ
π
θ
 
=  
 
= =
 
=  
 

1 2
2 2
cos cos
2 2 2 2
0 0
2 2
cos cos
2 2 2 2
02
2
d d
j j
d d
j j
E E E
E E e E e
e e
E E
π δ π δ
θ θ
λ λ
π δ π δ
θ θ
λ λ
   
− + +   
   
   
− + +   
   
= +
= +
+
=
Same amplitude, arbitrary phase difference
θ
r
cos
2
d
θ
0
0
0
2
2
2
2 cos cos
2 2
cos cos
2 2
E E
d
E E
E d
E
π δ
θ
λ
λ
π δ
θ
=
 
= + 
 
= =
 
= + 
 
cos
2
d
θ

Dynamic Antenna Array [1/2]
)
)
+∆
)
3
cosθ+∆
)
4
cosθ+∆
θ
(
)
cos
d
θ+∆
d
2
2 cosj d
e
π
θ
λ
−2
cosj d
e
π
θ
λ
−
( )s t( )s t( )s t( )s t
2
2 cosj d
e
π
θ
λ
+
2
cosj d
e
π
θ
λ
+
( )s t
∆
(2
cos
d
θ+∆
(3
cos
d
θ
(4
cos
d

Dynamic Antenna Array [2/2]
A dynamic antenna array can point in any direction to maximize the received signal
Enhanced receiver/transmitter antenna gain (reduced PA power, LNA gain)
Improved diversity
Reduced multi-path fadingReduced multi-path fading
Null/ Suppress interfering signals
Spatial power combining:
•Less power per PA
•Simpler PA architecture

BB Digital Beamforming
( ) ( )1M
s t− ( ) ( )1N
r t−
( )1s t 1
t
w 1
r
w ( )2r t
( )0s t 0
t
w 0
r
w ( )1r t
M
Optimal capacity for all channel conditions: min(M,N) data streams
Can support a variety of MA schemes (TDMA / OFDMA / SC-FDMA / SDMA)
High hardware complexity: M(N) full transceivers
High system power consumption
( ) ( )1M − ( ) ( )1N
r t−
( )1
t
M
w −
( )1
r
N
w −

BB Analog Beamforming
1
t
w 1
r
w( )s t
0
t
w 0
r
w
( )r t
M
1 data stream, antenna weights applied at “analog” baseband
Achieves high antenna gain in an arbitrary direction
Intermediate hardware complexity: M(N) RF mixers
Intermediate power consumption
( )1
t
M
w −
( )1
r
N
w −

RF Beamforming
1
r
w
( )s t
0
r
w
( )r t
M
1
t
w
0
t
w
Σ
1 data stream, RF phase shifters only, digitally controlled
Achieves high antenna gain in an arbitrary direction
Low hardware complexity: N RF phase shifters
Low system power consumption
No (or limited) support simultaneous transmissions to multiple users (e.g. OFDMA / SC-FDMA / SDMA)
( )1
r
N
w −( )1
t
M
w −

Long Term Fading of mmWave Channel
Beamforming is a transmission / reception scheme that can
be used to adapts to the long-term statistics of the channel
Question to answer: Will the long-term channel fading for
mmWave varies much faster than that of cellular waves?mmWave varies much faster than that of cellular waves?
Let’s look at the determinants of the long-term fading of a
wireless channel
• Pathloss
• Penetration loss
• Absorption due to atmosphere and/or precipitation
• Reflection, diffraction, and blocking

Long Term Fading of mmWave Channel
Pathloss
• Change depends on change of the location of the MS and the distance travelled – not
the carrier frequency
Penetration loss
• Change depends on change of the location of the MS and blockages in the path travelled
– again not depend on the carrier frequency
AbsorptionAbsorption
• Change depends on change of the location of the MS and distance travelled, not the
carrier frequency
Reflection, diffraction, blocking
• Change depends on change of the location of the MS and the path travelled, not the
carrier frequency
Observation
• The long term fading of mmWave channel induced by communication medium and
environment should not be significantly faster than that of the cellular waves

Beamforming and Channel Fading
Beamforming
enhances the gain
of the strongest
paths while
suppresses others
The good
Beamforming
increases the
sensitivity of
channel condition
to channel fading
The bad

The spatial selectivity of beamforming
• Use horn antenna as an example for analysis
• Gain of a horn antenna G ≈ 10log10(4.5AeλAhλ)
• 3 dB beamwidth of a horn antenna
• θ = 56 / A ,• θ3dB, E-plane = 56 / Aeλ,
• θ3dB, H-plane = 67 / Ahλ
• Assume θ3dB = θ3dB, E-plane = θ3dB, H-plane
• G ≈ 42.27 - 20log10θ3dB
Tradeoff between beamforming gain and beam adaptation overhead
and robustness of the channel
• The larger the Tx/Rx beamforming gain, the narrower the beamwidth
• Increased sensitivity to mobility
• More frequent beamforming adaptation needed

For BS Tx/Rx beamforming with < 30 dB antenna gain
• θ3dB ≈ 4.1 degree
• 7.2 meters wide @ 100 meter distance
• It takes 73.7 ms (589 MMB slots) for an MS moving at 350kmph to travel 7.2
meters
For MS Tx/Rx beamforming with < 20 dB antenna gainFor MS Tx/Rx beamforming with < 20 dB antenna gain
• θ3dB ≈ 13 degree
• 22.5 meters wide @ 100 meter distance
• It takes 231.1 ms (1849 MMB slots) for an MS moving at 350kmph to travel 22.5
meters
Observation
• The increased long term channel variation due to Tx/Rx beamforming in MMB is
on the order of tens of milliseconds or slower (hundreds of MMB slots or more)

Outline
• Introduction
• mmW spectrum
– Frame Structure
– RF beamforming
– Rain absorption
– Diffraction
architecture
challenges
– mmWave LNA
• Summary

RF Transceiver
Transceiver key RF components
• Antenna, Filters, Power Amplifier (PA), Low-Noise Amplifier
(LNA), Oscillator (VCO), Mixer and Data converters (DAC/ADC)

Nonlinear Device
In the most general sense, the output response of a nonlinear circuit
can be modeled as a Taylor series in terms of the input signal voltage
2 3
0 0 1 2 3
where the Taylor Coefficients are defined as
i i iv a a v a v a v= + + + +L
( )0 0
0
1
2
0
2 2
where the Taylor Coefficients are defined as
0
0
0
and higher order terms
ii
ii
a v
dv
a
vdv
d v
a
vdv
=
=
=
=
=
iv ov

Gain Compression
Consider the case where a single frequency sinusoid is applied to the input of a
nonlinear device such as a power amplifier
0 0
2 2 3 3
0 0 1 0 0 2 0 0 3 0 0
cos
cos cos cos
iv V t
v a aV t a V t a V t
ω
ω ω ω
ω
=
= + + + +
+
L
2 0
0 0 1 0 0 2 0
3 3 0 0
3 0 0 3 0
2 3
0 0 2 0 1 0 3 0 0
2
2 0 0 3
1 cos2
cos
2
cos cos21
cos
2 4
1 3
cos
2 4
1 1
cos2
2 4
t
v a aV t a V
t t
a V t a V
v a a V aV a V t
a V t a
ω
ω
ω ω
ω
ω
ω
+ 
= + + + 
 
+ 
+ + 
 
   
= + + + +   
   
+
L
3
0 0cos3V tω +L
0
3
1 0 3 0
2
1 3 0
0
3
Voltage gain at frequency
3
34
4
is negative in most practical amplifiers
aV a V
G a a V
V
a
ω
+
= = +

Intermodulation Distortion
Consider two-tone input voltage consisting of two closely spaced frequencies
2 1ω ω− 1 22ω ω− 2 12ω ω−
1ω 2ω
12ω 22ω
2 1ω ω+
13ω 23ω
2 12ω ω+1 22ω ω+
( )
( ) ( ) ( )
( ) ( )
0 1 2
2 32 3
0 1 0 1 2 2 0 1 2 3 0 1 2
2 2
0 1 0 1 1 0 2 2 0 1 2 0 2
2 2 3
2 0 1 2 2 0 1 2 3 0 1
cos cos
cos cos cos cos cos cos
1 1
cos cos 1 cos2 1 cos2
2 2
3 1
cos( ) cos( ) cos cos3
4 4
i
o
o
v V t t
v a aV t t a V t t a V t t
v a aV t aV t a V t a V t
a V t a V t a V t
ω ω
ω ω ω ω ω ω
ω ω ω ω
ω ω ω ω ω ω
= +
= + + + + + + +
= + + + + + +
+ − + + + +
L
3
1 3 0 2 2
3 3
3 0 2 1 2 1 2 3 0 1 2 1 2 1
1 2
3 1
cos cos3
4 4
3 3 3 3 3 3
cos cos(2 ) cos(2 ) cos cos(2 ) cos(2 )
2 4 4 2 4 4
Output spectrum consists of harmonics of the form
,
t a V t t
a V t t t a V t t t
m n m n
ω ω
ω ω ω ω ω ω ω ω ω ω
ω ω
   
+ +   
   
   
+ + − + + + + − + + +      
+ =
L
0, 1, 2 3,
These combinations of the two input frequencies are called intermodulation products
± ± ± L
2 1 1 22ω ω− 2 12ω ω− 2 1 2 12ω ω+1 22ω ω+

Third-Order Intercept Point (IP3)
1
1 2
2 2
1 0
2
2 2 6
2 3 0 3 0
1
2
1 3 9
2 4 32
These two powers are equal at the third-order IP
P a V
P a V a V
ω
ω ω−
=
 
= = 
 
1 0
2 2 2 6
1 3
1
2
3
2 2 1
3 1
3
These two powers are equal at the third-order IP
Let input signal voltage at the IP be
1 9
2 32
4
3
21
2 3IP
IP
IP IP
IP
V V IP
V
a V a V
a
V
a
a
P P a V
a
ω =
=
=
= = =

Mixer
IFf
LOf
RF LO IFf f f= ± RFf
LOf
IF RF LOf f f= ±
IFf LOf
LO IFf f+LO IFf f−
0
RF LO IFf f f− =
RF LOf f+LOf0 RFf
( ) ( ) ( )
( ) ( ) ( )
cos2 cos2
cos2 cos2
2
RF LO IF LO IF
RF LO IF LO IF
v t K v t v t K f t f t
K
v t f f t f f t
π π
π π
 = = 
 = − + + 
( ) ( ) ( )
( ) ( ) ( )
cos2 cos2
cos2 cos2
2
IF LO RF LO RF
IF RF LO RF LO
v t K v t v t K f t f t
K
v t f f t f f t
π π
π π
 = = 
 = − + + 

Image Frequency
IFf LOf
RF LO IFf f f= +
0
IM LO IFf f f= −
IFf LOf
IM LO IFf f f= +
0
RF LO IFf f f= −
2 IFf 2 IFf
-fIF is mathematically identical to fIF because the frequency spectrum of any real signal is
symmetric about zero frequency , and thus contains negative as well as positive frequencies
A received RF signal at the image frequency fIM is indistinguishable at the IF stage from the
desired RF signal of frequency fRF
( )
( )
IF RF LO LO IF LO IF
IF IM LO LO IF LO IF
f f f f f f f
f f f f f f f
= − = + − =
= − = − − = −
( )
( )
IF RF LO LO IF LO IF
IF IM LO LO IF LO IF
f f f f f f f
f f f f f f f
= − = − − = −
= − = + − =

Homodyne (Zero-IF) Receiver
( )
( )
( )
2
2
1 cos2
cos cos cos
2
After low pass filtering
1
2
1 cos2
sin sin sin
2
After low pass filtering
1
RF
RF RF RF
RF
RF RF RF
t
I t t t t
I t
t
Q t t t t
ω
ω ω ω
ω
ω ω ω
+
= = =
=
−
= = =
( )
1
2
Q t =
Benefits Drawbacks
Less hardware LO Leakage
Low power consumption DC offset errors
No IF stage and hence no image filter I/Q mis-match
Flicker (or 1/f) noise

Super-heterodyne Receiver
LOf
IFf
Benefits Drawbacks
Good sensitivity High Q filter
Good selectivity High performance oscillator
LNA output impedance matched to 50 ohm is
difficult
Integration of HF image reject filter is a major
problem

Wideband-IF Receiver
( )sin IF tω
( )cos IF tω
LOω
( )I t
( )Q t
( )'I t
( )cos IF tω
( )Q t
( )'Q t
Benefits Drawbacks
Image cancellation by IR mixer IR Mixer
Image rejection from the RF front-end pre-
selection filter
Good phase noise performance

Wideband-IF Receiver (Image Rejection)
( ) ( ) ( )
( ) ( ){ } ( ) ( ){ }
( ) ( ) ( )
cos cos cos
1 1
cos cos cos cos
2 2
cos cos sin
RF RF IM IM LO
RF IF RF LO IM IF IM LO
RF RF IM IM LO
I t x t x t t
x t t x t t
Q t x t x t t
ω α ω β ω
ω α ω ω α ω β ω ω β
ω α ω β ω
 = − + − 
   = − + + − + + + + −   
 = − + − 
Low-side injection
Signal of interest
Image
RF LO LO IM IFω ω ω ω ω− = − =
( )cos cos cos sin sinRF RF RF RF RF RFx t x t x tω α α ω α ω− = +
( )cos cos cos sin sinIM IM IM IM IM IMx t x t x tω β β ω β ω− = +
( ) ( ) ( )
( ) ( ){ } ( )
cos cos sin
1 1
sin sin sin sin
2 2
RF RF IM IM LO
RF IF RF LO IM IF IM
Q t x t x t t
x t t x t
ω α ω β ω
ω α ω ω α ω β ω
 = − + − 
 = − − + + − + + +  ( ){ }
( ) ( ) ( ) ( ) ( ) ( )
( ) ( ) ( ) ( )
( ) ( ) ( )
After low-pass filtering
1 1
cos cos , sin sin
2 2
1 1
' cos sin cos cos 2
2 2
1 1
' sin cos sin sin 2
2 2
LO
RF IF IM IF RF IF IM IF
IF IF RF IM IF
IF IF RF IM
t
I t x t x t Q t x t x t
I t I t t Q t t x x t
Q t I t t Q t t x x
ω β
ω α ω β ω α ω β
ω ω α ω β
ω ω α ω
 + − 
   = − + + = − − + +   
= − = + +
= + = + ( )
( ) ( )
After low-pass filtering
1 1
' cos , ' sin
2 2
IF
RF RF
t
I t x Q t x
β
α α
+
= =

Low-IF Receiver
( )2sin 2 LOf tπ
( )2cos 2 LOf tπ
( )2cos 2 LOf tπ
Benefits Drawbacks
Potential advantages of both heterodyne and
homodyne receivers.
ADC dynamic range
The IF frequency is just one or two channels
bandwith away from DC, which is just enough to
overcome DC offset problems.
Image reject mixer which is implemented in
digital baseband

Downlink RF Transceiver Requirement
Base station transmitter
•Transmit antennas / antenna arrays
• 20 – 30 dB antenna gain, horn antennas or phase antenna arrays (64 – 1024 elements)
•Power amplifier
• 20 – 50 dBm, >20% efficiency, EVM < 5% for OFDM waveform
•Packaging
• Integrated solution of antenna array / PA / MMIC / RFIC to minimize transmission loss• Integrated solution of antenna array / PA / MMIC / RFIC to minimize transmission loss
Mobile station receiver
• Receive antenna arrays
• 6 – 18 dB antenna gain, phase antenna arrays (4 – 64 elements)
• Receiver sensitivity < -80dBm
• Total Rx chain Noise Figure < 7dB
• Similar solutions exist today!
• 60GHz CMOS RFIC with phase antenna array (BWRC)
• 60GHz Single-chip integrated antenna and RFIC (GEDC)
• Packaging
• Integrated solution of antenna array / LNA / MMIC / RFIC to minimize transmission loss
94

Uplink RF Transceiver Requirement
Mobile station transmitter
• Transmit antenna arrays
• 6 – 18 dB antenna gain, phase antenna arrays (4 – 64 elements)
• Power amplifier
• 20 – 23 dBm, >20% efficiency, EVM < 5% for 16QAM single-carrier waveform
• Packaging• Packaging
• Integrated solution of antenna array / PA / MMIC / RFIC to minimize transmission loss
• Power consumption on the order of 100mW ~ 1W
Base station receiver
• Receiving antennas / antenna arrays
• 20 – 30 dB antenna gain, horn antennas or phase antenna arrays (64 – 1024 elements)
• Receiver sensitivity < -95 dBm
• Total Rx Noise Figure < 5dB
• Packaging
• Integrated solution of antenna array / PA / MMIC / RFIC to minimize transmission loss
95

Travelling Wave Tube (TWT) Power Amplifier
TWT amplifiers have been extensively used for high power applications at millimeter wave
frequencies
• Provides KWs to MWs power for satellite and radar
• Cost in 10K’s of US$ (too expensive for cellular)
Need to consider solid-state amplifier design for MMB

Solid-state Power Amplifier
Gallium-Nitride based power amplifier
•Wide bandgap materials such as gallium nitride (GaN) or silicon carbide (SiC) have much larger bandgaps
than conventional semiconductors
•Gallium-nitride High Electron Mobility Transistor (GaN HEMT) devices have breakdown voltages 10 times
higher than GaAs HEMT devices, allowing GaN HEMT devices to operate with much higher voltages
97
Source: “Gallium Nitride
(GaN) Microwave
Transistor Technology
For Radar Applications”,
Microwave Journal,
January 2008

Solid-state Power Amplifier
State-of-the-art for solid-state mmWave PAs
•11 Watts at 34 GHz (D. C. Streit, et. al., “The future of compound semiconductors for aerospace and
defense applications”, CSIC 2005)
•842 mW at 88 GHz (M. Micovic, et. al., “W-Band GaN MMIC with 842mW output power at 88 GHz”, IMS
2010)
•5.2 Watts at 95 GHz with a 12-way radial-line combiner (James Schellenberg, et. al., “W-Band, 5W solid-
state power amplifier/combiner”, IMS 2010)
98
Source: “Gallium Nitride
(GaN) Microwave
Transistor Technology
For Radar Applications”,
Microwave Journal,
January 2008

Cascaded Constructive Wave Amplifier
• Forward wave is amplified as it propagates along the transmission line
• Backward wave is attenuated as it propagates
• Distribution of N cascaded traveling wave stages
• Active devices along the transmission line provide feedback
• Relative phase of transmission line and active device determines amplification/
attenuation.
Source: J. Buckwalter and J. Kim, ISSCC 2009

Low-Noise Amplifier [1/2]
Single Stage 60 GHz LNA
Source: Javier Alvarado, PhD thesis, May 2008
Gain 12 dB
Noise Figure 5 dB over 57 – 64 GHz
Power Consumption 4.5mA from a 1.8 V source
1-dB compression point +1.5dBm
Efficiency 17.4%
Process IBM0.12 μm, 200 GHz fT, SiGe technology.

Low-Noise Amplifier [2/2]
Two Stage 23–32GHz LNA
Source: El-Nozahi et al,
IEEE JOURNAL OF SOLID-STATE CIRCUITS, FEB 2010
Gain 12 dB
Noise Figure 4.5–6.3dB over 23–32 GHz
Power Consumption 13mW from a 1.5 V source
IP3 -4.5dBm to -6.3dBm [stage1=-2dBm, stage2=7dBm]
Efficiency NA
Process Jazz Semiconductor 0.18 m BiCMOS
1
3, 3,1 3,2
1 1
tot
G
IP IP IP
= +

Outline
• Introduction
• mmW spectrum
– Frame Structure
– RF beamforming
– Rain absorption
– Diffraction
architecture
challenges
– mmWave LNA
• Summary

MMB downlink budget
MMB link downlink budget analysis Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8
Transmit Power (dBm) 35.00 40.00 35.00 40.00 35.00 40.00 35.00 40.00
Transmit Antenna Gain (dBi) 17.00 17.00 23.00 23.00 17.00 17.00 23.00 23.00
Carrier Frequency (GHz) 28.00 28.00 28.00 28.00 28.00 28.00 28.00 28.00
Distance (km) 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50
Key system configuration parameters
•Base station Tx power: 35dBm – 40dBm
•Base station Tx antenna gain: 17 dB – 23 dB
•Mobile station Rx antenna gain: 3 dB – 10 dB
Distance (km) 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50
Propagation Loss (dB) 115.32 115.32 115.32 115.32 115.32 115.32 115.32 115.32
Other losses 20.00 20.00 20.00 20.00 20.00 20.00 20.00 20.00
Receive Antenna Gain (dB) 3.00 3.00 3.00 3.00 10.00 10.00 10.00 10.00
Received Power (dBm) -80.32 -75.32 -74.32 -69.32 -73.32 -68.32 -67.32 -62.32
Bandwidth (MHz) 500 500 500 500 500 500 500 500
Thermal Noise PSD (dBm/Hz) -174.00 -174.00 -174.00 -174.00 -174.00 -174.00 -174.00 -174.00
Noise Figure 7.00 7.00 7.00 7.00 7.00 7.00 7.00 7.00
Thermal Noise (dBm) -80.01 -80.01 -80.01 -80.01 -80.01 -80.01 -80.01 -80.01
SNR (dB) -0.31 4.69 5.69 10.69 6.69 11.69 12.69 17.69
Implementation loss (dB) 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00
Spectram Efficiency 0.37 0.95 1.12 2.23 1.31 2.50 2.78 4.29
Data rate (Mbps) 186.08 474.53 559.37 1117.08 653.70 1250.93 1390.35 2145.23
Path loss formula: PL = 141.3 + 20log10d with d in km (free-space loss + 20dB)

MMB uplink budget
MMB uplink budget analysis Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8
Transmit Power (dBm) 20.00 23.00 20.00 23.00 20.00 23.00 20.00 23.00
Transmit Antenna Gain (dBi) 3.00 3.00 3.00 3.00 10.00 10.00 10.00 10.00
Carrier Frequency (GHz) 28.00 28.00 28.00 28.00 28.00 28.00 28.00 28.00
Distance (km) 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50
Key system configuration parameters
•Mobile station Tx power: 20dBm – 23dBm
•Mobile station Tx antenna gain: 3 dB – 10 dB
•Base station Rx antenna gain: 17 dB – 23 dB
Distance (km) 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50
Propagation Loss (dB) 115.32 115.32 115.32 115.32 115.32 115.32 115.32 115.32
Other losses 20.00 20.00 20.00 20.00 20.00 20.00 20.00 20.00
Receive Antenna Gain (dB) 17.00 17.00 23.00 23.00 17.00 17.00 23.00 23.00
Received Power (dBm) -95.32 -92.32 -89.32 -86.32 -88.32 -85.32 -82.32 -79.32
Bandwidth (MHz) 50 50 50 50 50 50 50 50
Thermal Noise PSD (dBm/Hz) -174.00 -174.00 -174.00 -174.00 -174.00 -174.00 -174.00 -174.00
Noise Figure 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00
Thermal Noise (dBm) -92.01 -92.01 -92.01 -92.01 -92.01 -92.01 -92.01 -92.01
SNR (dB) -3.31 -0.31 2.69 5.69 3.69 6.69 9.69 12.69
Implementation loss (dB) 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00
Spectram Efficiency 0.20 0.37 0.67 1.12 0.80 1.31 1.98 2.78
Data rate (Mbps) 9.92 18.61 33.32 55.94 39.92 65.37 98.96 139.03
Path loss formula: PL = 141.3 + 20log10d with d in km (free-space loss + 20dB)

Link Budget Analysis Summary
MMB downlink budget
• Low end: 35 dBm Tx power, 17 dB Tx antenna gain, 3 dB Rx antenna gain, 5 dB
implementation loss 180 Mbps on 500 MHz bandwidth at 500 meters
• High end: 40 dBm Tx power, 23 dB Tx antenna gain, 10 dB Rx antenna gain, 5 dB
implementation loss) 2145 Mbps on 500 MHz bandwidth at 500 meters
MMB uplink budgetMMB uplink budget
• Low end: 20 dBm Tx power, 3 dB Tx antenna gain, 17 dB Rx antenna gain, 5 dB
implementation loss 9.92 Mbps on 50 MHz bandwidth at 500 meters
• High end: 23 dBm Tx power, 10 dB Tx antenna gain, 23 dB Rx antenna gain, 5 dB
implementation loss 139 Mbps on 50 MHz bandwidth at 500 meters
Conclusion
• Assuming free-space plus 20dB path loss, MMB can provide 100 Mbps ~ 2 Gbps
cell-edge throughput on the downlink and 10 Mbps ~ 100 Mbps cell-edge
throughput on the uplink at 28 GHz for cell radius of 500 meters.

Link Level Performance
Length-432 and Length-1728 LDPC
Code rate 1/2, 5/8, 3/4, 13/16
Layered decoding
Maximum number of iterations

System Level Performance
19 cells wrap-around
12 sectors per cell
1 horn antenna per sector
20 dB antenna gain
• 17.5o 3-dB beamwidth in azimuth domain
• 10o 3-dB beamwidth in elevation domain
• 30 dB front-to-back ratio
Base station Tx power = 13, 16, 19,
22 dBm/MHz
Mobile station uniformly dropped
in the coverage area

Geometry with Single Rx Antenna
Site-to-site distance = 500
meters
Single Rx antenna with -1 dB
antenna gain
0.7
0.8
0.9
1
Interference
limited
3dB worse 5%-tile
geometry than cellular
No Rx beamforming
PLF1: PL = 141.3 + 20log10d
with d in km
12dB Lognormal shadowing
•8dB Lognormal shadowing for
cellular
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
-12.00 -9.00 -6.00 -3.00 0.00 3.00 6.00 9.00 12.00 15.00 18.00
Cellular,33dBmPerMHz 13dBmPerMHz, PLF1, NoBF
16dBmPerMHz, PLF1, NoBF 19dBmPerMHz, PLF1, NoBF
22dBmPerMHz, PLF1, NoBF

Geometry with Single Rx Antenna
0.7
0.8
0.9
1
meters
Single Rx antenna with -1 dB
antenna gain
2 – 6 dB worse 5%-tile
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
-12.00 -9.00 -6.00 -3.00 0.00 3.00 6.00 9.00 12.00 15.00 18.00
Cellular,33dBmPerMHz 13dBmPerMHz, PLF2, NoBF
16dBmPerMHz, PLF2, NoBF 19dBmPerMHz, PLF2, NoBF
22dBmPerMHz, PLF2, NoBF
No Rx beamforming
PLF2: PL = 157.4 + 32log10d
with d in km
•8dB Lognormal shadowing for
cellular

1
2
3
4
30
60
90
120
150
RxBeam 1
RxBeam 2
RxBeam 3
RxBeam 4
Mobile station Rx beamforming












=
+=
2
sin
2
sin
cos
ϕ
ϕ
θφϕ
N
AF
kd
210
240
270
300
330
180 04-element uniform linear array
N=4, d=λ/2, k=2π/λ
4 fixed beams (φ=0, π/2, π, 3π/2)
Mobile station orientation is random ~
U[0, 2π)
Mobile station selects the beam that
maximizes geometry
 2

Geometry with Rx Beamforming
0.7
0.8
0.9
1
meters
4-element antenna array with -
3 dB antenna gain per element
Interference
limited
The same 5%-tile
geometry as cellular
0
0.1
0.2
0.3
0.4
0.5
0.6
-12.00 -9.00 -6.00 -3.00 0.00 3.00 6.00 9.00 12.00 15.00 18.00
Cellular,33dBmPerMHz 13dBmPerMHz, PLF1, RxBF
16dBmPerMHz, PLF1, RxBF 19dBmPerMHz, PLF1, RxBF
22dBmPerMHz, PLF1, RxBF
Rx beamforming
PLF1: PL = 141.3 + 20log10d
with d in km
•8dB Lognormal shadowing for cellular

Geometry with Rx Beamforming
0.7
0.8
0.9
1
meters
4-element antenna array with -
3 dB antenna gain per element
0-3dB worse 5%-tile
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
-12.00 -9.00 -6.00 -3.00 0.00 3.00 6.00 9.00 12.00 15.00 18.00
Cellular,33dBmPerMHz 13dBmPerMHz, PLF2, RxBF
16dBmPerMHz, PLF2, RxBF 19dBmPerMHz, PLF2, RxBF
22dBmPerMHz, PLF2, RxBF
Rx beamforming
PLF1: PL = 157.4 + 32log10d
with d in km
•8dB Lognormal shadowing for cellular

System Throughput Analysis
MMB system performance analysis assumptions
Number of cells 19
Number of sectors per cell 12
Site to site distance 500 meters
Carrier frequency 28 GHz
System bandwidth 500 MHz
Path loss model
141.3 + 20log10d,
or 157.4 + 20log10d
Base station Tx power 40, 43, 46, or 49 dBmBase station Tx power 40, 43, 46, or 49 dBm
Base station Tx antenna configuration Single horn antenna
Base station Tx antenna gain 20 dB
Log-normal shadow fading STD 12 dB
Mobile station Rx noise figure 7 dB
Mobile station Rx antenna configuration
Single antenna, or Rx beamforming
with 4-element ULA
Mobile station Rx antenna gain
-1 dB for single antenna case,
-3 dB for ULA case
System overhead (cyclic prefix, control channels, etc.) 40%
Transceiver implementation loss 3 dB

System Throughput
4000
4500
5000
5500
6000
Cellthroughput(Mbps)
PLF1,NoBF
PLF2 provides higher
system throughput
than PLF1
30x LTE cell throughput
(4Tx MIMO per sector,
3-sector cell, 20MHz
system bandwidth)
2000
2500
3000
3500
4000
40 43 46 49
Cellthroughput(Mbps)
Base station transmit power per sector (dBm)
PLF1,NoBF
PLF2,NoBF
PLF1,RxBF
PLF2,RxBF
RxBF significantly
improves system
throughput
system bandwidth)

Cell-edge performance
80
100
120
140
edgethroughput(Mbps)
PLF1,NoBF
PLF1 allows better cell-
edge throughput than
PLF2
0
20
40
60
40 43 46 49
cell-edgethroughput(Mbps)
Base station transmit power per sector (dBm)
PLF1,NoBF
PLF2,NoBF
PLF1,RxBF
PLF2,RxBF
RxBF significantly
improves system
throughput

Outline
• Introduction
• mmW spectrum
– Frame Structure
– RF beamforming
– Rain absorption
– Diffraction
architecture
challenges
– mmWave LNA
• Summary

Summary
Millimeter wave spectrum (3-300GHz) can potentially provide the bandwidth
required for mobile broadband applications for the next few decades and
beyond.
•Opportunity to open 200 times the spectrum currently allocated for cellular below 3GHz.
Propagation and other losses due to rain, foliage and penetration through
building materials needs better understandingbuilding materials needs better understanding
Millimeter waves are also attractive for mobile application due to small
component sizes such as antennas.
•Further research is needed towards components and devices that meets mobile application
demand of higher power and efficiency
Wireless community should take on the growing data demand by exploiting
millimeter wave spectrum paving the way for multi-Gbps mobile broadband.

Millimeter Wave Mobile Broadband: Unleashing 3-300 GHz Spectrum

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