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1 S C I E N C E P A S S I O N T E C H N O L O G Y u www.tugraz.at High-accuracy Positioning in Multipath Channels: Location-Awareness for 5G Networks and Beyond 29-5-2018, COST IRACON, Cartagena, Spain Klaus Witrisal Joint work with my PhD students / Post Docs: Paul Meissner, Erik Leitinger, Stefan Grebien, Josef Kulmer, Thomas Wilding, Anh Hong Nguyen, Michael Rath

High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

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Page 1: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

1

S C I E N C E P A S S I O N T E C H N O L O G Y

u www.tugraz.at

High-accuracy Positioning in Multipath Channels:

Location-Awareness for 5G Networks and Beyond

29-5-2018, COST IRACON, Cartagena,

Spain

Klaus Witrisal

Joint work with my PhD students / Post Docs:

Paul Meissner, Erik Leitinger, Stefan Grebien, Josef Kulmer, Thomas Wilding,

Anh Hong Nguyen, Michael Rath

Page 2: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

2 2 High-accuracy Positioning: Applications

Introduction

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Manufacturing Retail

Logistics Smart Labeling Assisted Living

Autonomous Driving

Requirements:

Accuracy (5 – 20 cm);

Reliability (90 – 100%)

Challenges:

Heterogeneity: scenarios and

technologies; multipath

Objectives:

Positioning and navigation;

activity recognition; control

Fotos: Ubisense, SES-magotag GmbH, brighamyen.com, Witrisal, Jungheinrich, slashgear.com

Page 3: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

3 3 Location-aware Communications: many system parameters depend on the position

Introduction

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Di Taranto et al., “Location-Aware Communications for 5G Networks”, IEEE Signal Proc. Mag., Nov. 2014]

Page 4: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

4 4 Outline

Introduction

Ranging and positioning in dense multipath

Bandwidth scaling (1) and MIMO gain (2)

Multipath-assisted indoor positioning (3)

Theory and modeling

Algorithms

Cognitive positioning and location awareness (4)

Conclusions

High-accuracy Positioning in Dense Multipath Channels

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Four ingredients for high-accuracy positioning

and location awareness

Page 5: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

5 5 An experiment: transmission of a (UWB) pulse in an indoor environment

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Page 6: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

6 6 Time-of-flight Ranging

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Page 7: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

7 7 Time-of-flight Ranging: Problem: Multipath Radio Propagation

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Page 8: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

8 8

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Time-of-flight Ranging: Problem: Multipath Radio Propagation

Page 9: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

9 9

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Time-of-flight Ranging: Problem: Multipath Radio Propagation

Page 10: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

10 10 Signal Processing for Robust Ranging (& Pos.)

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Experiment

Modelling

Performance limits

Algorithms

Improvements

Page 11: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

11 11 Modeling the dense multipath to derive the theoretical limit (CRLB)

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Received signal from anchor j located at p(j): (s(t): TX signal)

[Witrisal et al. "Bandwidth Scaling and Diversity Gain for Ranging and Positioning

in Dense Multipath Channels," IEEE Wireless Commun. Lett., 2016.]

Page 12: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

12 12 CRLB for ranging (in dense multipath (DM)) AWGN only

CRLB

mean-squared bandwidth

signal-to-noise ratio

CRLB scales with squared

bandwidth and SNR

AWGN + dense multipath

CRLB whitening

BW gain

reduced SNR due to DM

cost for nuissance estim.

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Witrisal et al. "Bandwidth Scaling and Diversity Gain for Ranging and Positioning

in Dense Multipath Channels," IEEE Wireless Commun. Lett., 2016.]

Page 13: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

13 13 Ranging error bound and SINR shows the bandwidth scaling

Parameters

SNR = 30 dB

KLOS = 1 … LOS-to-DM-power

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Witrisal et al. "Bandwidth Scaling and Diversity Gain for Ranging and Positioning

in Dense Multipath Channels," IEEE Wireless Commun. Lett., 2016.]

bandwidth

detectability:

ML estimator

CRLB in

multipath

CRLB

in AWGN

Page 14: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

14 14

anchor 3

anchor 1

agent: p anchor 2

Position error bound Fisher information

Position error variance (CRLB):

J independent measurements:

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

ranging direction matrix

geometry of nodes

[Y. Shen and M. Win, "Fundamental Limits of Wideband Localization; Part I: A General Framework,"

IEEE Trans. Inform. Theory, vol. 56, no. 10, pp. 4956-4980, October 2010. ]

Page 15: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

15 15

anchor 1

agent: p anchor 2

(2) Diversity (MIMO) gain Fisher information

J independent measurements:

Diversity combining (SIMO,

MISO, MIMO):

approx. equal geometries

effective SINRs are added up:

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Witrisal et al. "Bandwidth Scaling and Diversity Gain for Ranging and Positioning

in Dense Multipath Channels," IEEE Wireless Commun. Lett., 2016.]

SINR gain

2 x 2 MIMO

gain = 4-fold;

STDV halved

Page 16: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

16 16 Multi-antenna configurations – diversity (MIMO) gain for ranging

4 x 4 MIMO vs. SISO (1 x 1)

16 independent measm.

16-fold SINR (LOS-to-

multipath-power-ratio):

theoretical limit reduced by

factor 4

detection probability

strongly improved

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Witrisal et al. "Bandwidth Scaling and Diversity Gain for Ranging and Positioning

in Dense Multipath Channels," IEEE Wireless Commun. Lett., 2016.]

SISO ~ 1/100

1m

10cm

1cm 1/4

100MHz

Page 17: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

17 17 CRLB for angle estimation (phased array) AWGN only

CRLB for AoA

squared effective aperture

signal-to-noise ratio

CRLB scales with fc (carrier),

squared aperture and SNR

AWGN + dense multipath

CRLB in DM

reduced SNR due to DM

multipath interference

limits the performance

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [T. Wilding, et al., "AoA and ToA accuracy for antenna arrays

in dense multipath channels," in ICL-GNSS, June 2018.]

Page 18: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

18 18

2 antenna elements

16 antenna elements

Multi-antenna configurations – diversity gain for angle estimation in dense multipath

CRLB for AoA

uniform linear array (ULA)

bandwidth scales SINR

matched filter diverges

from CRLB

minimum SINR needed

for maximum likelihood

16-element array

> 20-fold aperture

16-fold SINR

detectability strongly

improved

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [T. Wilding, et al., "AoA and ToA accuracy for antenna arrays

in dense multipath channels," in ICL-GNSS, June 2018.]

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19 19 Application to RFID – experimental validation

Wideband/UWB RFID Readers:

UWB for ranging

DSSS signal (@ 50 MHz) for ranging (TU Vienna, Arthaber)

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Arthaber, Faseth, Galler, Communications Letters 2015]

[Arnitz, Muehlmann, Witrisal; Electronics Letters 2010]

[Hinteregger et al., IEEE RFID 2016]

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20 20 Position error bound and MIMO gain: applied to multistatic RFID positioning

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

1 range 1 range

1 TRX 1 TRX 1 TRX 1 TRX

1 bi

1 TX; 1 RX 1 TX; 1 RX

2 bistatic 1 range 1 range 4 range 4 range

2 TX, 2 RX 2 TX, 2 RX

8 bistatic

Three configurations are compared:

1. Each reader has:

1 antenna for TX and RX (1 TRX)

yielding 2 range measurements

2. Each reader has:

separated TX/RX antennas

yielding 2 range + 2 bistatic meas.

3. Each reader has

2 pairs of separated TX/RX ant.

yielding 8 independent range plus

8 independent bistatic measurem.

[Hinteregger, Witrisal, et al., "MIMO Gain and Bandwidth Scaling for RFID Positioning in

Dense Multipath Channels," in 2016 IEEE Intern. Conf. on RFID, 2016. ]

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21 21 Position error bound and MIMO gain: applied to multistatic RFID positioning

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Three configurations are compared:

1. Each reader has:

1 antenna for TX and RX (1 TRX)

yielding 2 range measurements

2. Each reader has:

separated TX/RX antennas

yielding 2 range + 2 bistatic m.

3. Each reader has

2 pairs of separated TX/RX ant.

yielding 8 independent range plus

8 independent bistatic measurem.

[Hinteregger, Witrisal, et al., "MIMO Gain and Bandwidth Scaling for RFID Positioning in

Dense Multipath Channels," in 2016 IEEE Intern. Conf. on RFID, 2016. ]

Page 22: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

22 22 Integration Measurement Campaign

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

3 Campaigns

•TU Graz Demoroom

•Detego – Semi-industrial hall

•TU Wien Laboratory

Page 23: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

23 23 Integration Measurement Campaign - Results

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

TU Graz – Maximum Likelihood

Page 24: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

24 24 Integration Measurement Campaign - Results

Ranging and positioning in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

TU Graz – Positioning Accuracy

Page 25: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

25 25 Conclusion (1)

High-accuracy positioning in dense multipath requires large

bandwidth and/or multi-antenna systems

5G systems to employ mm-wave and massive MIMO!

Ranging and positioining in dense multipath

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Page 26: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

26 26 Outline

Introduction

Ranging and positioning in dense multipath

Bandwidth scaling (1) and MIMO gain (2)

Multipath-assisted indoor positioning (3)

Theory and modeling

Algorithms

Cognitive positioning and location awareness (4)

Conclusions

High-accuracy Positioning in Dense Multipath Channels

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Page 27: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

27 27 Multipath-assisted Indoor Navigation and Tracking

(MINT) – concept and geometric model

Idea:

exploit range/position

information from reflected

multipath

Benefits:

less anchor nodes;

more redundancy, i.e.

robustness in NLOS;

higher accuracy

Geometric model (GPEM):

virtual anchors (VAs) (mirror

sources)

Multipath-assisted indoor positioning – theory and modeling

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Meissner, Steiner, Witrisal, "UWB Positioning with Virtual Anchors

and Floor Plan Information," in WPNC, Dresden, March 2010.]

Page 28: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

28 28 Signal Model (Geometry-based stochastic channel model - GSCM)

Received signal: (s(t): TX signal)

K deterministic multipath components

Anchor (LOS), virtual anchors (NLOS), deterministic scatterers

Diffuse multipath v(t)

PDP

MPCs characterized by

Multipath-assisted indoor positioning – theory and modeling

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Page 29: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

29 29

Position error variance is bounded by

If no “path-overlap” occurs (orthogonal signals from VAs)

effective SINRk determines ranging information intensity

for MPC from k-th virtual anchor

Ranging direction matrix accounts for geometry

Position error bound for MINT (Cramér-Rao lower bound derived from LHF)

Multipath-assisted indoor positioning – theory and modeling

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Leitinger, et al., "Evaluation of Position-related Information in Multipath

Components for Indoor Positioning," IEEE JSAC, 2015.]

Page 30: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

30 30 Validation of the signal model – and prediction of the position error bound

Multipath-assisted indoor positioning – theory and modeling

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Meissner, Witrisal, "Analysis of Position-Related Information in Measured UWB Indoor Channels," EUCAP 2012.]

[Meissner, "Multipath-Assisted Indoor Positioning," Ph.D. Thesis, Graz University of Technology, 2014.]

Page 31: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

31 31 Tracking algorithms exploiting multipath • (1) data association of multipath ranges and state-space tracking

• (2) ranging uncertainty is estimated from multipath amplitudes

• (3) a SLAM-style algorithm is used to discover new VAs

Multipath-assisted indoor positioning – algorithms

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

GSCM update

GPEM update [Meissner, Witrisal, et al., "UWB for Robust Indoor Tracking: […],” IEEE Wireless Commun. Lett., 2014.]

[Leitinger, Witrisal, et al., "Multipath-assisted Indoor Simultaneous Localization and Mapping,“ ICC Workshops, 2015.]

[Witrisal, et al., "High-Accuracy Localization for Assisted Living,“ IEEE Signal Processing Mag., March 2016.]

data assoc.

Page 32: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

32 32 Experimentation employing a lab-grade UWB channel sounder

Validation steps:

GSCM/GPEM-based simulation model measurement-based

analysis channel-sounder-based real-time implementation (2 anchors) (1 anchor)

Multipath-assisted indoor positioning – algorithms

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Meissner, et al, "Real-Time Demonstration System for Multipath-Assisted

Indoor Navigation and Tracking (MINT)," IEEE ICC Workshops 2014. ]

Page 33: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

33 33 Online model updates GPEM – environment model

• position and cov. of VAs

GSCM – channel model

• SINR-values of MPCs

Multipath-assisted indoor positioning – algorithms

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

blackboard, anchor 1

left windows, anchor 2

[Leitinger, Witrisal, et al., "Multipath-assisted Indoor Simultaneous Localization and Mapping,“ ICC Workshops, 2015.]

Page 34: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

34 34 Tracking performance

Analysis of accuracy and robustness (non-diverging runs)

Channel/environment model awareness yields robustness

Multipath-assisted indoor positioning – algorithms

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Meissner, Witrisal, et al., "UWB for Robust Indoor Tracking: Weighting of Multipath Components

for Efficient Estimation,“ IEEE Wireless Commun. Lett., 2014.]

Page 35: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

35 35 Experimentation

Lab-grade UWB channel sounder (IlmSense; > 40 kEUR)

Can it be replaced by low-cost hardware?

DecaWave DW1000 based radio nodes

Multipath-assisted indoor positioning - experimentation

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Decawave

EVK1000 Sequitur: DW1000 +

Raspberry Pi

Pozyx: DW1000 +

Arduino

[J. Kulmer, et al., "Using DecaWave UWB Transceivers for High-accuracy

Multipath-assisted Indoor Positioning," in IEEE ICC Workshops, May 2017.]

Page 36: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

36 36 DecaWave DW1000 – RX Pulse shape obtained from DW1000 chip

Channel 2 (500 MHz) (top); Channel 4 (900 MHz) (bottom) sampled at 1.016 GHz (oversampled for time-domain fig.)

unknown time alignment

Raised-cosine pulse;

duration ~2.4ns

Raised-cosine pulse;

duration ~1.5ns

Multipath-assisted indoor positioning - experimentation

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [J. Kulmer, et al., "Using DecaWave UWB Transceivers for High-accuracy

Multipath-assisted Indoor Positioning," in IEEE ICC Workshops, May 2017.]

Page 37: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

37 37 Analysis of Multipath-Components SINR-values in dB; two alignment methods

DW1000 and channel sounder reach similar levels

(difference ~ 1 – 2 dB, consistently)

SINRs: “LOS” is best; “white board” and “window”

still promising for positioning

Multipath-assisted indoor positioning - experimentation

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

DecaWave DW1000 Channel Sounder

[J. Kulmer, et al., "Using DecaWave UWB Transceivers for High-accuracy

Multipath-assisted Indoor Positioning," in IEEE ICC Workshops, May 2017.]

Page 38: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

38 38 Approximate ML Positioning

AWGN model (neglect DM)

approximate log likelihood

Monte Carlo sampling

Multipath-assisted indoor positioning - experimentation

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [J. Kulmer, et al., "Using DecaWave UWB Transceivers for High-accuracy

Multipath-assisted Indoor Positioning," in IEEE ICC Workshops, May 2017.]

Page 39: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

39 39 Positioning performance at 100 measurement positions; DW 1000

Ch. 4 (900 MHz)

beats Ch. 2 (500

MHz)

Select (virtual)

anchors based on

SINR values

improves

robustness

Multipath-assisted indoor positioning - experimentation

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [J. Kulmer, et al., "Using DecaWave UWB Transceivers for High-accuracy

Multipath-assisted Indoor Positioning," in IEEE ICC Workshops, May 2017.]

Page 40: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

40 40 Low-cost dependable UWB positioning: Using adaptable directive antenna

Single-anchor positioning:

Multipath components are

exploited

Challenge:

Very large bandwidth needed

(~ 2 GHz) to separate

multipath components

Solution:

directive antenna; separation

of multipath components in

angular domain

Multipath-assisted indoor positioning - experimentation

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [M. Rath, et al., "Multipath-assisted Indoor Positioning Enabled by

Directional UWB Sector Antennas," in IEEE SPAWC, 2017.]

Page 41: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

41 41 Sectorized Antenna: Performance Results

Experiments based on measured signals

One fixed anchor at a1

Agent positon p to be estimated

Bandwidth is 500 MHz

Likelihood function:

Probability of p given the measurement

Sectorized antenna yields clear

solution

CDF of position error:

Accuracy (60 cm 25 cm @ 90 %)

Robustness (55 % 90 % @ 25 cm)

Outliers (10 % > 0.6 m 0 %)

Multipath-assisted indoor positioning - experimentation

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

conventional antenna sectorized antenna

[M. Rath, et al., "Multipath-assisted Indoor Positioning Enabled by

Directional UWB Sector Antennas," in IEEE SPAWC, 2017.]

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42 42 Maximum-Likelihood Positioning – using a single mm-wave access point

accurate estimation of multipath delays high position accuracy

7 x 7 array at the anchor (massive MIMO)

AoA resolution: multimodality is reduced

Multipath-assisted indoor positioning – algorithms

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal [Witrisal, et al., "High-Accuracy Localization for Assisted Living,“ IEEE Signal Processing Mag., March 2016.]

Page 43: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

43 43 Conclusions (2)

A multipath-assisted indoor positioning system relies on models

of geometry and channel characteristics (environment model)

benefits from location awareness, raising robustness

yields location awareness to the underlying communications

system (predictability of PHY-layer performance indicators)

A single access point can support high-accuracy positioning in

UWB, 5G networks, etc.

large bandwidth and smart antenna yield delay and angle

resolution of MPCs

Multipath-assisted indoor positioning

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Page 44: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

44 44 Outline

Introduction

Ranging and positioning in dense multipath

Bandwidth scaling (1) and MIMO gain (2)

Multipath-assisted indoor positioning (3)

Theory and modeling

Algorithms

Cognitive positioning and location awareness (4)

Conclusions

High-accuracy Positioning in Dense Multipath Channels

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Page 45: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

45 45 Cognitive dynamic system – an engineering view inspired by cognitive neuroscience

Perception-action cycle (PAC)

sensed environment in a closed

loop control of sensing

Cognitive perceptor

extracts and separates relevant

information (memory, attention)

Cognitive controller

act on the environment to

maximize information gain

Probabilistic reasoning

mediates reciprocal coupling

Hierarchical structure

different abstraction layers

Cognitive positioning and location awareness

26-4-2018

Klaus Witrisal [Haykin and Fuster, Proceedings of the IEEE, 2014.]

[Leitinger, “Cognitive Indoor Positioning and Tracking using Multipath Channel Information,“ Ph.D. Thesis, TU Graz, 2016.]

Page 46: High-accuracy Positioning in Multipath ChannelsAWGN + dense multipath CRLB in DM reduced SNR due to DM multipath interference limits the performance Ranging and positioning in dense

46 46 Conclusions Large bandwidth / multiple

antennas

yields high accuracy

Exploiting multipath

yields high robustness

Cognitive positioning

to yield high efficiency, low

latency, etc.

foreseen evolution of wireless

networks

5G: mm-wave, massive MIMO

is becoming available (e.g.) with

5G mm-wave systems

environment model

mission critical positioning

massive RFID tag populations

full location awareness

High-accuracy Positioning in Dense Multipath Channels

29-5-2018, COST IRACON, Cartagena, Spain

Klaus Witrisal

Time has come for high-accuracy positioning, given current

technology trends

Location awareness is a way of the future for communications

and positioning in 5G and beyond