Millimeter Wave: the future of commercial wireless...
Transcript of Millimeter Wave: the future of commercial wireless...
Sildes are © Robert W. Heath Jr. 2016
Millimeter Wave: the future of commercial wireless systemsProfessor Robert W. Heath Jr.
Wireless Networking and Communications GroupDepartment of Electrical and Computer EngineeringThe University of Texas at Austin
Also with MIMO Wireless Inc (see http://www.mimowireless.com)
www.profheath.org
Thanks to the National Science Foundation Grant No. NSF-CCF-1319556, NSF-CCF-1527079, NSF-CCF-1514275, the Intel / Verizon 5G program, the U.S. Department of Transportation through the Data-Supported Transportation Operations and Planning (D-STOP) Tier 1 University Transportation Center, the the Texas Department of Transportation under Project 0-6877, and gifts from Nokia, MERL, Huawei, and Toyota InfoTech.
New operational regimes for wireless
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Sildes are © Robert W. Heath Jr. 2016
*Image modifed fromF. Bocardi, R. Heath, A. Lozano, T. Marzettaand P. Popovski, “Five Disruptive Technology Directions for 5G,” IEEE Commun. Mag., 2014
Forbidden region
Number of users
Dat
a ra
tes
1 10,000100010010
b/s
kb/s
Mb/s
Gb/s
Motivation for new 5G cellular
technologies, but also applies to wireless LAN
Need new technology that can provide high data rates
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Wireless fundamentals
rate per user =bandwidth
# of users
X MIMO
(bits per second)Number of active users (devices) decreases with more frequency reuse, improve via smaller cells, sectoring, or multiuser MIMO
Limited by the standard, amount of spectrum owned by the operator, finite supply per FCC
MIMO spatial multiplexing gain requires multiple antennas and good propagation conditions, requires supporting more antennas in the standard
spectral efficiency
Depends on signal power, noise power and interference power, improves with interference cancellation
X
Bandwidth is the key to higher data rates
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Why millimeter wave (mmWave)?
Spectrum available Bandwidth per channel
WiFicomparison
Maximumbandwidth
MIMO Claimedpeakrates(downlink)
Rate youmightactuallyget…
IEEE802.11ac 160MHz 8 6.7Gbps 700 MbpsIEEE802.11ay 4GHz 2 24Gbps TBD
800 MHz vs. 27 GHz
Comparing cellular + WiFi below 6 GHz and likely bands from 28 GHz to 90 GHz
100 MHz vs. 500 MHz vs. 2 GHzComparing cellular with carrier aggregation versus possible mmWave bandwiths at 30 GHz and 72 GHz carriers
33x 5-20x
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Example gains in application to 5G cellular
Surprise - mmWave gains are more than a spectrum multiplier!
Upper cmWave 28 GHz:500 MHz (expect 10x)
mmWave 72 GHz:2 GHz (expect 40x)
0.0
20.0
40.0
60.0
80.0
100.0
120.0
28sparse 28dense 72sparse 72dense0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
28sparse 28dense 72sparse 72dense
5%
X c
apac
ity im
prov
emen
t
Average
Baseline 2 GHz w/50 MHz BW
* Note the fine print about dense networks
38x
62x
58x
95x
* T. Bai and R. W. Heath Jr., “Coverage and rate analysis for millimeter wave cellular networks”, IEEE Trans. Wireless Commun., Feb. 2015. ** T. Bai, A. Alkhateeb, and R. W. Heath, Jr., ̀ `Coverage and Capacity of Millimeter Wave Cellular Networks," IEEE Communications Magazine, Sept. 2014.
Use of antennas at mmWave
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© Robert W. Heath Jr.
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Antenna arrays to provide enough aperture
Directional transmission with large arrays provides necessary gain
TX RXhighly directive transmission highly directive receptionaperture at a
conventionalfrequency
aperture at mmWave
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The antenna arrays are small at mmWave
* From https://www.ifixit.com/Teardown/Samsung+Galaxy+S7+Teardown/56686** W. Roh et al. "Millimeter-wave beamforming as an enabling technology for 5G cellular communications: theoretical feasibility and prototype results," in CommunicationsMagazine, IEEE , vol.52, no.2, pp.106-113, February 2014
antennas are about 10 mm
Samsung Galaxy S7* Mockup of a Galaxy with mmWave**
(the large objects are antenna connectors, used only for prototyping)
Base station may have 64 to 512 antennas
Mobile station may have 4 to 32 antennas
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Benefits of directional transmission
Interference reduction in mmWave gives even better rates
Strong interference happens much less often
Sidelobe interference is weaker
Rate gain when only accounting for stronger signal
Additional gain from less interferencein the narrower beams
pointy beam fat beam
20 x gain
2 x gainra
te m
ultip
lier
Rethinking RF and baseband
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© Robert W. Heath Jr.
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Design considerations for mmWave MIMO systems, circuits & devices
MIMO architectures implementing directional transmission are different at mmWave
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?
?
?? Nt ?
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MIMO system at < 6 GHz frequencies
Conventional MIMO heavily leverages digital signal processing
BasebandPrecoding
MIMOCombining
and Equalization
ADC
ADC
ADC
RFChain
RFChain
RFChain
2 to 8 antennas
# antennas = # RF = # pairs ADCs
Bandwidths of 5-100 MHz
MIMOPrecoding
DAC
DAC
DACRF
Chain
RFChain
RFChain
Power consumption impacts MIMO architecture
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Unlikely to dedicate a separate RF chain and ADC for each antenna
Power at 60 GHz1GHz BW
BasebandPrecoding
Baseband processing
ADCRFChain
LNA
ADCRFChain
LNA
20mW 250 mW
40mW
* R. Méndez-Rial, C. Rusu, N. González-Prelcic, A. Alkhateeb and R. Heath “Hybrid MIMO Architectures for MmWave Communications: Phase shifters or switches? , IEEE Access 2016.** R. Heath, N. González-Prelcic, S. Rangan, W. Roh and A. Sayeed, “An Overview of Signal Processing Techniques for Millimeter Wave MIMO Systems”, IEEE JSTSP, 2016
Freq. Band. NRX Powerconsumption
2.8GHz 20MHz
4 120mW
6GHz 1GHz 4 2 W!!!!
High cost and powerconsumption
of mmWave components
Large antennasystems
at mmWave
MIMO architectures at mmWave: analog beamforming
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RFChain
Phase shifters
RFainDAC BasebandBaseband RFChain
RFainADCH
beamformernetwork of phase shifters
combiner
Limited to single stream and single user MIMO* J.Wang, Z. Lan, C. Pyo, T. Baykas, C. Sum, M. Rahman, J. Gao, R. Funada, F. Kojima, H. Harada et al., “Beam codebook based beamforming protocol for multi-Gbpsmillimeterwave WPAN systems,” IEEE Journal on Selected Areas in Communications, vol. 27, no. 8, pp. 1390–1399, 2009.** S. Hur, T. Kim, D. Love, J. Krogmeier, T. Thomas, and A. Ghosh, “Millimeter wave beamforming for wireless backhaul and access in small cell networks,” IEEE Transactions on Communications, vol. 61, no. 10, pp. 4391–4403, 2013..
Consumption in the phase shifter depends on
the angle resolution
Phase shiftersapply for the entire band
Constant gain and quantized angles
MIMO architectures at mmWave: hybrid precoding
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Combine analog and digital beamforming
Flexible approach for multi-stream MIMO or multiuser MIMO at mmWave
BasebandPrecoding
1-bitADC
DAC
1-bitADCDAC
RFChain
RF Precoding
1-bitADCDAC
1-bitADCDAC
BasebandCombining
Nt NrLt LrNs Ns
RF Combining
FBB FRF WBBWRF
RFChain
RFChain
RFChain
*Ahmed Alkhateeb, Jianhua Mo, Nuria González Prelcic and Robert W. Heath, Jr., ̀ `MIMO Precoding and Combining Solutions for Millimeter Wave Systems,'' IEEE Communications Magazine, vol. 52, no. 12, 122-131, December 2014.
>= 1
>= 1
Number of DACs / ADCs is generally << # of antennas
Analog beamformingwith multiple RF chains
MIMO architectures at mmWave: combining with 1-bit ADCs
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BasebandPrecodingBasebandProcessing
1-bitADC
1-bitADC
1-bitADC
1-bitADC
RFChain
RFChai
n
TransmitProcessing
H
l Overview of precoding and combining
FBB
FRF
WBB
WRF
H
y “ ?⇢W˚
BBW˚RFHFRFFBBs ` W˚
BBW˚RFv
}FRFFBB}2F § 1
FRF P FWRF P W
y “ ?⇢W˚
BB˜HFBBs ` W˚
BB˜v
l Beam training
y “ ?⇢w˚
RFHfRFs ` v
fRF
w˚TRF
�3 bit “ t1, ej⇡{4, j, ej3⇡{4,´1, ej5⇡{4,´j, ej7⇡{4uF “ � ˆ ¨ ¨ ¨ ˆ �
tf‹RF,w
‹RFu “ argmin
fPF ,wPW|w˚Hf |2
yk,`rns “ ?⇢w˚
kHf`trns ` vk,`rns
tk‹, `‹u “ argmin
k,`
Nt´1ÿ
n“0
|yk,`rnst˚rns|2
y “ ?⇢W˚
BBW˚RFHFRFFBBs ` W˚
BBW˚RFv
y “ ?⇢pFTAc
BS,D b W˚AMS,DqADz ` v
y(1) “ ?⇢(1)
`FT
(1)AcBS,D b W˚
(1)AMS,D˘z ` v1
y(2) “ ?⇢(2)
`FT
(2)AcBS,D b W˚
(2)AMS,D˘z ` v2
...
y(S) “ ?⇢(S)
`FT
(S)AcBS,D b W˚
(S)AMS,D˘z ` vS
rFps,kqs˚:,maBSp¯�uq “
"Cs if u P Is,k,m0 if u R Is,k,m
l Low resolution
y “ Q pHs ` vqy “ sign pHs ` vq
2
l Overview of precoding and combining
FBB
FRF
WBB
WRF
H
y “ ?⇢W˚
BBW˚RFHFRFFBBs ` W˚
BBW˚RFv
}FRFFBB}2F § 1
FRF P FWRF P W
y “ ?⇢W˚
BB˜HFBBs ` W˚
BB˜v
l Beam training
y “ ?⇢w˚
RFHfRFs ` v
fRF
w˚TRF
�3 bit “ t1, ej⇡{4, j, ej3⇡{4,´1, ej5⇡{4,´j, ej7⇡{4uF “ � ˆ ¨ ¨ ¨ ˆ �
tf‹RF,w
‹RFu “ argmin
fPF ,wPW|w˚Hf |2
yk,`rns “ ?⇢w˚
kHf`trns ` vk,`rns
tk‹, `‹u “ argmin
k,`
Nt´1ÿ
n“0
|yk,`rnst˚rns|2
y “ ?⇢W˚
BBW˚RFHFRFFBBs ` W˚
BBW˚RFv
y “ ?⇢pFTAc
BS,D b W˚AMS,DqADz ` v
y(1) “ ?⇢(1)
`FT
(1)AcBS,D b W˚
(1)AMS,D˘z ` v1
y(2) “ ?⇢(2)
`FT
(2)AcBS,D b W˚
(2)AMS,D˘z ` v2
...
y(S) “ ?⇢(S)
`FT
(S)AcBS,D b W˚
(S)AMS,D˘z ` vS
rFps,kqs˚:,maBSp¯�uq “
"Cs if u P Is,k,m0 if u R Is,k,m
l Low resolution
y “ Q pHs ` vqy “ sign pHs ` vq
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With few bits
With one bit
2b bits per complex dimension
threshold in real / imaginary
NrNt
10mW1 bit, 240 Gs/s
much less at 4 Gs/s
*J. Mo, P. Schniter, N. G. Prelcic and R. W. Heath, Jr. “Channel Estimation in Millimeter Wave MIMO Systems with One-Bit Quantization”, Asilomar 2014**C. Rusu, R. Mendez-Rial, N. Gonzalez-Prelcic and R. W. Heath, "Adaptive One-Bit Compressive Sensing with Application to Low-Precision Receivers at mmWave," 2015 IEEE Global Communications Conference (GLOBECOM), San Diego, CA, 2015, pp. 1-6.
Higher BB complexity
Exploit sparsity using 1-bit CS to estimate the channel
Ultra low power solution
Application areas for mmWave
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WPAN at 60 GHz
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Standard Bandwidth Rates Approval
WirelessHD 2.16 GHz 3.807 Gbps Jan.2008
WirelessHD 1.1 2.16 GHz 4 x 7.138 Gbps Jan.2010
Sony wearable HDTV *
* http://www.wirelesshd.org/consumers/product-listing/
Epson projector *
Dell Laptop *
ZyxelAeroBeam HDTV kit *
Multimedia streaming especially HDMI
Peripheral connections
Kiosk data transfer
Compliant products available
Widely seen as the first 60 GHz consumer product
WLAN at 60 GHz
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Standard Bandwidth Rates Approval Date
IEEE 802.11ad 2.16 GHz 6.76 Gbps Dec. 2012
Wilocity’s chipset**
Tensorcom’s chipset***
• http://nitero.com/ ** http://wilocity.com *** http://www.tensorcom.com/ **** http://www.ieee802.org/11/Reports/ng60_update.htm
Nitero chipset*Gbps peak throughputs
Chipsets available and products are shipping
In-room LANcable replacement
Next gen is currently in development (802.11ay) targeting 100 Gbps
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Wearables at 60 GHz
Augmented reality glasses
Wireless headset
Smart watch
Fitness trackers
Device to track dog’s activity
Connected person
Connected pet
Smart phone
*A. Pyattaev, K. Johnsson, S. Andreev, and Y. Koucheryavy, “Communication challenges in high-density deployments of wearable wireless devices,” IEEE Wireless Communications, vol. 22, pp. 12–18, February 2015.**K. Venugopal, M. Valenti, and R. W. Heath, Jr., ̀ ` Device-to-Device Millimeter Wave Communications: Interference, Coverage, Rate, and Finite Topologies ,'' submitted to IEEE Trans. on Wireless, June 2015.Also on ArXiv. See related ITA version as well.
Likely realized using IEEE 802.11ad or WirelessHD at 60 GHz
High data rates for high-end devicesReasonable isolation for low-
end devices
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5G cellular networks (28 GHz, 38GHz, 60GHz, E-Band, etc)
mmWaverelay
mmWavesensing-BS
mutiband BS
mmWavebackhaul
Multiband connectivity
Self-backhaulednetwork
Many new components of 5G infrastructure
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Connected cars
MmWave is the only viable approach for high bandwidth connected vehicles*
V2V communication beams
Vehicle driving cloud
directionalbeamforming
blockageV2I communicationbeam
Joint communicationand radar
*Junil Choi, Nuria González-Prelcic, Robert Daniels, Chandra R. Bhat, and Robert W. Heath Jr, “Millimeter Wave Vehicular Communication to Support Massive Sensing”, to appear in IEEE Communications Magazine.
Sensing technologies can be used to help establish mmWave links
Exchanging raw sensor data is possibe
Enables high data rateinfotainment applications
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Robotics
Cloud for robots
Laser scanner
Central unit
Pressure sensor
Tactile sensor
Videocameras
Sonar
Central unit sending sensing data to the
operator
Applications in drones and robots for industry, agriculture,
security, surgery, …
Large amount of sensors sending data to the central unit
Inertial motionsensor
IR camera
Radar
3D image sensor
Millimeter wave is coming to a wireless system near you
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© Robert W. Heath Jr.
Check out research videos at goo.gl/yYx250
www.profheath.org