Press Conference, Rome 21 Dec 2012. Kai Borre, Professor Department of Electronics, Danish GPS Center, Aalborg University, Denmark

1. DANISH GPS CENTER
GNSS
and
Positioning for the Future
Kai Borre
Danish GPS Center, Aalborg University, Denmark

2. DANISH GPS CENTER
GNSS Development Schedule
• GPS and
GLONASS
evolved slowly
in the first
decades
• In the last
decade the
development
of space and
ground control
segments is
intense
14/12/2011 Copyright © 2011 by Kai Borre 2
Test & deployment GPS III
GPS II
202020122010 2015
COMPASS
COMPASS 1 (end date unknown)
Test & deployment of L5
GPS III FOC
L1C FOC
L5 FOC
L2C Full Operational Capability (FOC)
GLONASS Full Operational Capability (FOC)
COMPASS 2 test & depl. COMPASS 2/3, regional service; global service depl. COMPASS 3 FOC
New
signals
FOC
SDCM design/tests
GLONASS-M
(launched until
2012)
GLONASS-K2 (KM after 2015)
New: L1OC, L3OC, L1SC, L2SC (CDMA), SAR
GLONASS-K1
New: L3OC (CDMA),
SAR
Galileo launch
Sys. testbed v1/v2 IOV Deployment
Galileo operational
SDCM fully deployed
18 SV OC
Test & deployment of L1C
Test & deploym. of L2C, staged roll-out of CNAV
Courtesy of Darius Plaušinaitis

3. DANISH GPS CENTERThe Menu of Future GNSS Signals
• Originally GPS and
GLONASS offered
one civilian signal on
one carrier
• Future GNSS offer
system diversity and
frequency diversity
System Signal
Carrier
frequency
[MHz]
Component Type
Data rate
[sps/bps]
Modulation
Chipping
rate
[Mcps]
Code length
[chips]
Full
length
[ms]
GLONASS L1
OF 1605.375-
1609.3125
standard Data -/50
BPSK
0.511 511 1
SF high accur. Military 5.11
COMPASS B1 1575.42
B1-CD
Open
100/50
MBOC(6,1,1/11) 1.023
B1-CP -/-
B1 Authorized
100/50
BOC(14,2) 2.046
-/-
Galileo E1 1575.42
A PRS cosBOC(15,2.5) 2.5575
B Data, SOL 250/125
CBOC(6,1,1/11) 1.023
4092 4
C Pilot, SOL -/- 4092 * 25 100
GLONASS L1 OC/SC 1575.42
GPS L1 1575.42
C/A Data -/50 BPSK 1.023 1023 1
P(Y)
Military
BPSK 10.23 7 days 7 days
M BOC(10,5) 5.115
Galileo E6 1278.75
A PRS cosBOC(10,5)
B Data 1000/500
BPSK(5) 5.115
5115 1
C Pilot -/- 5115 * 100 100
COMPASS B3 1268.52
B3
Authorized
-/500 QPSK(10) 10.23
B3-AD 100/50
BOC(15,2.5) 2.5575
B3-AP -/-
GLONASS L2
OF 1242.9375-
1248.1875
standard Data -/50
BPSK
0.511 511 1
SF high accur. Military 5.11
GPS L2 1227.6
L2 CM Data
50/25
or -/50 TM and BPSK 0.5115
10230 20
L2 CL Pilot -/- 767250 1500
P(Y)
Military
BPSK 10.23 7 days 7 days
M BOC(10,5) 5.115
GLONASS L3 OC 1207.14 QBSK(10)
GLONASS L3 OF/SF
1201.743-
1208.088
COMPASS B2 1191.795
B2aD
Open
50/25
AltBOC(15,10) 10.23
B2aP -/-
B2bD 100/50
B2bP -/-
Galileo
E5
(1191.795)
E5a 1176.45
a-I Data 50/25
AltBOC(15,10) 10.23
10230 * 20 20
a-Q Pilot -/- 10230 * 100 100
E5b 1207.14
b-I Data, SOL 250/150 10230 * 4 4
b-Q Pilot, SOL -/- 10230 * 100 100
GPS L5 1176.45
I Data 100/50
QPSK 10.23 10230
1
Q Pilot -/- 1
14/12/2011 Copyright © 2011 by Kai Borre 3
Courtesy of Darius Plaušinaitis

4. DANISH GPS CENTER
GNSS Signal Changes
• Increasing requirements to positioning, increasing
number of systems ask for redesign of GNSS signals
14/12/2011 Copyright © 2011 by Kai Borre 4
– New modulations are needed due to
• More heavy shearing of spectrum
• More signals per carrier
• Improved ranging performance
– New PRN code generators (Kazami,
Weil, Neuman-Hoffman) are
considered in addition to the
traditional Gold codes
• Several signals in a system and
several systems are using the same
carrier
• Better performance of week signals
• Better interference performance
• Better ranging performance
Figure source – “GPS World”
GNSS L1 (carrier) spectrum

5. DANISH GPS CENTERGlobal Navigation Satellite Systems
• GPS (II – 1980)
• GLONASS (1993)
• COMPASS
• Galileo
14/12/2011 Copyright © 2011 by Kai Borre 5
2006
~1981
• 80’s-90’s – the first professional
GPS + GLONASS receivers
• 2011 – “launch year” for the first
consumer, mobile phone GPS +
GLONASS receiver chips (from
Qualcomm, Broadcom, ST-
Ericsson, u-blox and others)

6. DANISH GPS CENTER
Relative Accuracy of Clocks
• Clock stability influences signal and
observation related parameters
14/12/2011 Copyright © 2011 by Kai Borre 6
Clock type Applications
Relative accuracy
[s/s]
Temperature compensated
crystal oscillator (TCXO)
Watches, clocks, consumer GNSS
receivers, mobile phones
10-6 – 5×10-7
Oven controlled crystal
oscillator (OCXO)
Geodetic GNSS receivers 10-7 – 10-8
GPS disciplined oscillator
(GPSDO) – GPS + above clock
Time and frequency synchronization 10-9 – 10-12
Chip scale atomic clock (CSAC)
Future high performance GNSS
receivers
5×10-12
Rubidium atomic clock Special space and terrestrial
applications that require extra high
stability and accuracy
10-11 – 10-12
Cesium atomic clock 10-12 – 10-13
Hydrogen maser
Space (new application) and
terrestrial applications
10-15 – 10-16

7. DANISH GPS CENTER
Satellite Based Augmentation
System (SBAS)
• The primary driver for SBAS is aviation applications
that require high safety
• SBAS provides services that are not available in GPS
or other existing systems
14/12/2011 Copyright © 2011 by Kai Borre 7
– DGPS type corrections for
improved standard receiver
precision
– Massive signal integrity
monitoring and user alert in
less than 6 seconds from
the start of an integrity
failure
– Other system safety and
service quality data that are
vital for reliable positioning

8. DANISH GPS CENTERSpace Based Augmentation Systems
• Wide Area Augmentation System (WAAS), USA
• European Geostationary Navigation Overlay Service
(EGNOS)
• System for Differential Correction and Monitoring
(SDCM), Russia
• GPS And Geo-Augmented Navigation (GAGAN)
system, India
• Quasi-Zenith Satellite System (QZSS), Japan
• Multi-functional Satellite Augmentation System
(MSAS), Japan
14/12/2011 Copyright © 2011 by Kai Borre 8

9. DANISH GPS CENTER
Alternative Systems
• Research and development continuously
adapt to or modify existing systems to provide
positioning services
– Legacy ground based systems (no perspectives)
– WiFi (very limited capabilities)
– Mobile Networks (does not meet today’s GNSS
precision level, new versions under development)
– TV (DVB) signals based
– Proprietary, local (for example LOCATA)
– New methods based on GPS+LEO satellites (for
example Boeing Timing & Location)
14/12/2011 Copyright © 2011 by Kai Borre 9

10. DANISH GPS CENTERBoeing Timing & Location (BTL) I
• BTL Geo-location builds on Transit heritage. It
complements GPS with an enhanced version
of the existing Iridium system
• BTL Geo-location provides key technical
advantages in 2 parts – (GPS-based systems
can not do this)
– Iridium signal power (BTL) >> GPS – Iridium
penetrates buildings better
– Spot beams form unique local contours. Extremely
difficult to spoof (today spoofing is of big concern
for civil applications in the GNSS world)
14/12/2011 Copyright © 2011 by Kai Borre 10

11. DANISH GPS CENTERBoeing Timing & Location (BTL) II
14/12/2011 Copyright © 2011 by Kai Borre 11

12. DANISH GPS CENTERBoeing Timing & Location (BTL) III
14/12/2011 Copyright © 2011 by Kai Borre 12
Figure source – Wikipedia

13. DANISH GPS CENTER
Receiver Development
14/12/2011 Copyright © 2011 by Kai Borre 13

14. DANISH GPS CENTERCurrent Receiver Development
Copyright © 2011 by Kai Borre 14
2007 Future
Research and
development
2008-2010
•Snapshot techniques
•High sensitivity
•Multi-system & multi-
frequency receiver
•Multipath mitigation
•Antenna arrays
•Further SDR
development
•GNSS integrity
•Integration of other
positioning methods
14/12/2011

15. DANISH GPS CENTER
Matlab SDR Plots
Copyright © 2011 by Kai Borre 15
4 4.005 4.01 4.015 4.02 4.025 4.03 4.035
x 10
4
-2000
0
2000
4000
6000
Samples (time)
Correlation
Real correlation result from GNSS SDR
-1 0 1 2
0
0.5
1
1.5
Code Offset [chips]
Correlation
Theoretical
correlation
0 5 10 15 20 25 30
0
5
10
15
Acquisition results
PRN number (no bar - SV is not in the acquisition list)
AcquisitionMetric
Not acquired signals
Acquired signals
14/12/2011

16. DANISH GPS CENTER
Matlab SDR Conclusions
• An extremely convenient educational tool
• Quick prototyping
– A demo acquisition for Galileo in less than an hour
– Students have converted the GPS SDR to EGNOS
and Galileo SDRs in ~6 months
• Very convenient exploration of particular
signal cases (anomalies) or algorithms
because the GNSS signal record can be
replayed again and again …
• Acceleration of some key signal processing
steps is much recommended
Copyright © 2011 by Kai Borre 1614/12/2011

17. DANISH GPS CENTER
The Old Setup (Virtex IIP)
• Virtex IIP 50
FPGA
• GPS
front-end
from Simrad
• 1 bit samples
• 16 HW
channels
• Adjustable
correlator
spacing (on
the fly)
• About 50%
FPGA in use
• PPC cores
not used
Copyright © 2011 by Kai Borre 17
Old
front-end
New
front-
end
14/12/2011

18. DANISH GPS CENTER
DGC SDR Simulink Model
• Simulink receiver version allows modularity
and out of the box good visual representation
• The modularity gives benefits similar to the
Software Communications Architecture (SCA)
Copyright © 2011 by Kai Borre 18
The adaptor block inside
calls nearly unmodified C
code of the FPGA receiver
14/12/2011

19. DANISH GPS CENTER
Simulink Model Plots
Copyright © 2011 by Kai Borre 1914/12/2011

20. DANISH GPS CENTER
The ML507 Setup
Copyright © 2011 by Kai Borre 20
Battery
adapter
New
front-end
14/12/2011

21. DANISH GPS CENTER
DGC Receiver Results
Copyright © 2011 by Kai Borre 2114/12/2011

22. DANISH GPS CENTER
DGC Receiver Results
Copyright © 2011 by Kai Borre 22
4 m 8 m
14/12/2011

23. DANISH GPS CENTER
Future DGC Receiver Version
• Universal channels for GPS, Galileo, and other GNSS
signals (BOC, BPSK, and other types)
• Real-time operation with optional GNSS signal
recording or processing of such signal records
• Possible options
– Flexible support for multiple front-ends to process multiple
carriers or antennas
– Plotting on a PC of receiver tracking in real-time (non real-
time version already exists)
– Processing of other, non-GNSS signals (under consideration)
• Modular design (friendly for student project)
• Inspiration: AGGA-4, GNU Radio, Artus (IFEN) and
others…
Copyright © 2011 by Kai Borre 2314/12/2011

24. DANISH GPS CENTER
Thank You For Your Attention
Also visit http://gps.aau.dk
Copyright © 2011 by Kai Borre 2414/12/2011
DGC is organizing an international
workshop with the same title as the present
talk on August 27-September 2, 2012 at the
North Sea, Denmark. Interested participants
should contact borre@gps.aau.dk