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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*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


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


4

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


5

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


8

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

10



11

Design considerations for mmWave MIMO systems, circuits & devices

MIMO architectures implementing directional transmission are different at mmWave

??

?

?

?? Nt ?


12

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˚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˚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˚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

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

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


© Robert W. Heath Jr. 21

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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Check out research videos at goo.gl/yYx250

www.profheath.org

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