Dual Frequency performance in mass market

1. 1 Broadcom Proprietary and Confidential. © 2018 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.| Broadcom Standard TechnologyBroadcom Proprietary and Confidential. © 2018 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.
Dual Frequency performance in mass market

2. 2 Broadcom Proprietary and Confidential. © 2016 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.|
GAL E5a/GPS L5 signal characteristics
• Center frequency 1176.45 MHz
• More powerful signals
• Pilot signal has no data bits
– Use simple PLL versus Costas loop
– 6dB theoretical tracking advantage
• Chipping rate 10.23 MHz versus 1.023MHz for L1
30
m
300m
E5a/L5
L1

3. 3 Broadcom Proprietary and Confidential. © 2016 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.|
How does multipath affect L1 and how does it affect L5
GIF courtesy of Google

4. 4 Broadcom Proprietary and Confidential. © 2018 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.| Broadcom Standard Technology
L5 GNSS Forecast
SVs available at
the end of 2018
Number of SVs
now
Number of SVs at
the end of 2018
SVs available now

5. 5 Broadcom Proprietary and Confidential. © 2018 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.| Broadcom Standard Technology
L5/E5 satellites in orbit
Only based on the increasing
available signals in space, L5
receivers improve their
performance significantly year
over year!
GAL 0 1 3 3 3 6 12 16 20 23 24
BDS 0 0 0 0 0 0 0 2 10 20 22
QZSS 1 1 1 1 1 1 1 4 4 4 4
GPS 1 2 3 4 8 11 12 13 14 16 18
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

6. 6 Broadcom Proprietary and Confidential. © 2016 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.|
L5 GNSS receivers have higher sensitivity, because the
signal strength is higher
Broadcom Standard
Technology

7. 7 Broadcom Proprietary and Confidential. © 2016 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.|
Range error in function of signal power (L1 and L5)

8. 8 Broadcom Proprietary and Confidential. © 2016 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.|
Red: BCM4774 (L1)
Green: BCM4775 (L1+L5)

9. 9 Broadcom Proprietary and Confidential. © 2018 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.| Broadcom Standard Technology
Open Sky
CDF Plot
MetersMeters

10. 10 Broadcom Proprietary and Confidential. © 2018 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.| Broadcom Standard Technology
Urban Driving
CDF Plot
MetersMeters

11. 11 Broadcom Proprietary and Confidential. © 2018 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.| Broadcom Standard Technology
Urban Pedestrian
CDF Plot
MetersMeters

12. 12 Broadcom Proprietary and Confidential. © 2016 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.|
Summary: L5 has a faster accuracy improvement
roadmap
2018 2019 2020
L5 higher
resolution,
higher multipath
rejection and
higher receive
signal strength
Growing
amount of
L5/E5 signals
due to satellite
launches
Proprietary L5
multipath
improvements

13. 13 Broadcom Proprietary and Confidential. © 2016 Broadcom. All Rights Reserved. "Broadcom" refers to Broadcom Limited and/or its subsidiaries.|
Summary and next steps
• Until today mass market devices were single frequency only
• Industry is moving towards dual frequency
– Increase of accuracy in open environment
– More robust to multipath in urban scenarios
• Number of SVs broadcasting in the L5 band are growing every year
• Carrier phase measurements have been improved
– E.g Better cycle slip detection
• Broadcom HW (BCM4775) is also capable of tracking the full E5 signal and
L2
– E5a+E5b might be enabled in future releases
• Broadcom Successfully tested RTK and PPP internally