5G – A Different PHYlosophy?

Nicola Marchetti

CPqD, Campinas, Brazil

November 6, 2013

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies

• 5G - A Different PHYlosophy?

OUTLINE

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies

• 5G - A Different PHYlosophy?

OUTLINE

What I do at a Glance

Complex Systems Theory

Physical Layer

&

Radio Resource

Management

for

Optical and Wireless

Systems

PHY

RRM

4

What I do at a Glance (2)

Many Base

Stations

Many

Antennas

Radio Resource

Management

Synchronization

5

What I do at a Glance (3)

Free

Spectrum

Detection

Complex

Communication

Systems

Optical

Wireless

Integration

6

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies

• 5G - A Different PHYlosophy?

OUTLINE

Cellular Network Evolution

• HSDPA/HSUPA (2005-08) – 3GPP Rel 5/6

– 14 / 5.7 Mbps peak DL/UL

– CDMA & Diversity

• HSPA+ (2008-09) – 3GPP Rel 7

– 28 / 11 Mbps peak DL/UL

– CDMA & MIMO

• LTE (2010-11) – 3GPP Rel 8

– 100 / 50 Mbps peak DL/UL

– OFDMA & SC-FDMA & MIMO

8

• LTE-A (2012-13) – 3GPP Rel 9/10

– 1 Gbps / 500 Mbps peak DL/UL

– OFDMA & SC-FDMA & MIMO

• 5G (2013-?)

– 10+ Gbps / 5+ Gbps peak DL/UL

– Power & cost reduction

– New bands, Self-organization, Massive MIMO, Small cells

3.5

G

3.9

G

4

G

5

G

Is PHY Research still needed?

• Spectral efficiency more antennas, higher modulation order, ultra dense deployment (and related channel understanding), distributed schemes (and related synchronization issues)

• Power efficiency small cell deployments, coordinated beamforming (CoMP)

• Cost reduction cheaper deployments (small cells), cheaper bands (mm-wave, LSA)

• All the above has a lot to do with PHY !!! 9

Cooper’s Law

10

•More Spectrum •Frequency Division •Modulation & Coding •Spectrum Reuse

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies – More Spectrum

– Frequency Division

– Modulation & Coding

– Spectrum Reuse

– EU ADEL Project

• 5G - A Complex Matter?

OUTLINE

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies – More Spectrum

– Frequency Division

– Modulation & Coding

– Spectrum Reuse

– EU ADEL Project

• 5G - A Complex Matter?

OUTLINE

The “Sweet” Spot

• Opportunistic spectrum access: spectrum sharing paradigm that allows unlicensed secondary users to opportunistically access spectrum holes, called white spaces, in the bands for which the primary users hold a license

• Although Cognitive Radio systems can be envisaged in any part of the radio spectrum, the frequency range considered more appropriate for their implementation is located between 100 MHz and 10 GHz

• This includes the 300-3000 MHz range that OFCOM has dubbed the sweet spot for spectrum sharing

13

Bands & Spectrum Access Techniques

14 F. Paisana, N. Marchetti, L. DaSilva, “Radar, TV and Cellular Bands: Which Spectrum

Access Techniques for Which Bands?”, IEEE Communications Surveys &Tutorials,

accepted for publication subject to minor revisions

Enhanced Carrier Aggregation

J. McMenamy, I. Macaluso, N. Marchetti, L. Doyle, “A Framework for Enhanced Carrier

Aggregation with Dynamic Carrier Selection”, Wireless Days 2013 15

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies – More Spectrum

– Frequency Division

– Modulation & Coding

– Spectrum Reuse

– EU ADEL Project

• 5G - A Complex Matter?

OUTLINE

Uplink Synchronization

17

Uplink Synchronization (2)

• Detection techniques with very low complexity

– Utilization of the symmetrical behaviour of interference among different subcarriers

18 A. Farhang, N. Marchetti, L. Doyle, “Low Complexity LS and MMSE Based CFO Compensation

Techniques for the Uplink of OFDMA Systems”, IEEE International Conference on Communications 2013

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies – More Spectrum

– Frequency Division

– Modulation & Coding

– Spectrum Reuse

– EU ADEL Project

• 5G - A Complex Matter?

OUTLINE

Massive MIMO

2.4 GHz

20 F. Bentosela, N. Marchetti, H. Cornean, “MIMO Capacity: Transition from Linear to

Logarithmic Growth”, IEEE Transactions on Antennas and Propagation, under review

Massive MIMO (2)

F. Bentosela, N. Marchetti, H. Cornean, “MIMO Capacity: Transition from Linear to

Logarithmic Growth”, IEEE Transactions on Antennas and Propagation, under review

21

• How to integrate mobile and fixed access networks?

• How to jointly optimize the overall network?

Optical-Wireless Integration

22

Inter Base Station Communications

• To perform handover and more advanced cooperation schemes, base stations need to communicate with low latency

• It is necessary to investigate if the tree architecture has a good performance or if other architectures should be considered

• Cooperative multipoint transmission/reception (CoMP) – Data and control information can be multicasted

to base stations, exploiting the broadcasting nature of the Passive Optical Network

23

mm-Wave & Massive MIMO • Using very high carrier frequencies (up to hundreds of GHz)…

• …one can squeeze more antennas in the same base station/device

• Target Line Of Sight short range (up to ~100m) communications at the beginning

• Later on we expect to start to look into Non Line Of Sight wider range communication (distributed massive MIMO/CoMP, with many antennas at each base station, and base stations coordinating their transmissions)

24

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies – More Spectrum

– Frequency Division

– Modulation & Coding

– Spectrum Reuse

– EU ADEL Project

• 5G - A Complex Matter?

OUTLINE

26

27

28

Higher Throughput & Lower Power

29

C. Galiotto, N. Marchetti, L. Doyle, “The Role of the Total Transmit Power on the Linear

Area Spectral Efficiency Gain of Cell-Splitting”, IEEE Communications Letters, accepted

for publication, to appear

30

31

Spectrum Management and ICIC in HetNet

Inter-Cell Interference Coordination via spectrum

management

Mitigation of the harm of interference on

macro-cell edge users

Reduction of overall network

throughput

GOAL:

Guaranteeing cell-edge user throughput with limited reduction of overall network throughput

32

User Operating Points

33 C. Galiotto, N. Marchetti, L. Doyle, “Flexible Spectrum Sharing and Interference Coordination for Low

Power Nodes in Heterogeneous Networks”, IEEE Vehicular Technology Conference 2012

LPN =

Low Power Node

MBS =

Macro Base Station

PF =

Proportional Fair

scheduler

Results

34 C. Galiotto, N. Marchetti, L. Doyle, “Flexible Spectrum Sharing and Interference Coordination for Low

Power Nodes in Heterogeneous Networks”, IEEE Vehicular Technology Conference 2012

Complex Communication Systems

35

I. Macaluso, H. Cornean, N. Marchetti, L. Doyle, “Complex Communication Systems

Achieving Interference-Free Frequency Allocation”, IEEE International Conference on

Communications 2014, submitted

Self-Organizing Channel Assignment

36

04.2

29.1

CE

h

I. Macaluso, H. Cornean, N. Marchetti, L. Doyle, “Complex Communication Systems

Achieving Interference-Free Frequency Allocation”, IEEE International Conference on

Communications 2014, submitted

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies – More Spectrum

– Frequency Division

– Modulation & Coding

– Spectrum Reuse

– EU ADEL Project

• 5G - A Complex Matter?

OUTLINE

Advanced Dynamic spectrum 5G mobile

networks Employing Licensed shared access

Seventh Framework Programme for Research of the European Commission

ADEL

Key Idea To explore the potential of Licensed Shared Access (LSA) as a key

enabler of 5G mobile broadband networks

By developing:

1) Collaborative sensing techniques

2) Dynamic radio-aware resource allocation

3) Cooperative communication

With the final goal of providing:

– An order of magnitude improvement in spectral efficiency

– More energy & cost efficient mobile broadband networks

EU project ADEL

39

Facts

• 2.5 M euro (270 K euro for CTVR)

• Small or medium-scale focused research project (STREP) – ranked 4th out of 130 at EU level

• 8 partners (5 academia, 3 industry)

• 3 years (Dec 1, 2013 – Nov 30, 2016)

40

Motivation

• Key driver: to meet the growing capacity demands in cellular networks imposed by the increasing customer base and data- hungry mobile applications

• Key concept: The “Licensed Shared Access” (LSA) (a.k.a. “Authorised Shared Access” – ASA) paradigm wherein:

incumbent operators may allow others to share their spectrum at specific times and places, according to an agreed set of rules

• State-of-the-art: the use of spectrum in commercial applications is either licensed or license-exempt . Cognitive radio is another approach but it has been met with scepticism by cellular operators and has led to very limited deployments (e.g. 802.22)

41

LSA concept and basic architecture

1) Shared use of spectrum based on radio cognition

2) Implemented via individual authorisation scheme ensuring QoS

3) Access rights can be granted on a temporary or long term basis

[Issues RRM commands]

[Computes rule-based

LSA spectrum availability]

[Contains incumbent’s spectrum usage

information in frequency, time & space]

Operations

Administration

& Management

42 J. Khun-Jush, P. Bender, B. Deschamps, and M. Gundlach, “Licensed shared access as complementary approach to

meet spectrum demands: Benefits for next generation cellular systems,” ETSI Workshop on on Reconfigurable Radio

Systems, December 2012

Component technologies

• Collaborative spectrum sensing

• Signal processing techniques for sensing

• Interference channel estimation and interferer localisation

• Cooperative communication

• Dynamic resource allocation

• Policy violation detection / policy reinforcement

With the above, we believe that ADEL will lead to future

heterogeneous wireless networks of an order of magnitude higher capacity and energy efficiency thus setting the

roadmap for the adoption of spectrum flexible broadband wireless systems by 2020

43

Work package structure

Project Management

(WP1)

Licensed Shared Access

Resource Allocation

Techniques

(WP4)

Platform Development and Experimental Evaluation

(WP6)

Dissemination & Exploitation Planning

(WP2)

Dynamic Spectrum

Access

(WP5)

Scenarios, Requirements and Network Architecture Definition

(WP3)

“Who,

When,

Where”

“How”

44

Concrete results expected • Spectral efficiency: a factor of 10 is aimed at

• Energy efficiency: also a factor of 10 is anticipated

• Cost: at least a factor of 10 improvement for mobile data traffic

via the use of small cells with LSA

• Experimental platforms: are expected to show some of these

gains over-the-air, as well as over large-scale system level

simulations

IRIS

WARP

Open

Air

45

• What I do at a Glance

• Is PHY Research still needed?

• 5G Technologies

• 5G - A Different PHYlosophy?

OUTLINE

Are Comm Systems Complex?

Many different networks coming together

• Optical & wireless

• WiFi, LTE, sensors, RFID etc.

• Many simple devices densely deployed

• Many antennas

47

Highly dynamical systems • high variability in time, but also in frequency and space

domains

Are Comm Systems Complex?

• Self-organization and need to mimic bio-inspired decentralized behaviours

– Evolution (but not only)

– Emergence of (complex) patterns

48

Trend towards

increasing complexity