Nordic Semiconductor Asa · OSL:NOD

Nordic Semiconductor Asa — Technical Presentation (December 2022)

44 slides from Nordic Semiconductor Asa's technical presentation, December 2022

  1. Slide 1: Bluetooth Direction Finding

    Bluetooth Direction Finding Nordic offering Paal Kastnes December 2022

  2. Slide 2: Practicalities

    © Nordic Semiconductor Practicalities  Duration: about 60 minutes  Questions are encouraged!  Please type questions in the top of the right sidebar  All questions are anonymous  Try to keep them relevant to the topic  We will answer towards the end  The chat is not anonymous, and do not use f

  3. Slide 3: Today’s Speakers

    © Nordic Semiconductor Today’s Speakers Finn Boetius Paal Kastnes Product Marketing Engineer Technical Marketing Manager Host Speaker

  4. Slide 4: Bluetooth AoA/AoD

    Bluetooth AoA/AoD Nordic offering Paal Kastnes December 2022

  5. Slide 5: Agenda

    © Nordic Semiconductor Agenda  Introduction  AoA vs AoD  The physics involved in direction finding  IQ samples and how to use them  Scope of Bluetooth specification for Direction Finding  Bluetooth standard data formats  Connected vs. connectionless  Periodic Advertising  nRF Connect SDK sa

  6. Slide 6: Introduction to direction finding

    Introduction to direction finding 6

  7. Slide 7: Direction Finding

    © Nordic Semiconductor Direction Finding  Hallmark feature of Bluetooth 5.1 Core Specification  Requires additional HW radio support  Optional feature  Enables positioning solutions based on direction of a signal using phase detection θ?  First Bluetooth standard to support real life positionin

  8. Slide 8: Direction Finding – use cases

    © Nordic Semiconductor Direction Finding – use cases Asset tracking Wayfinding Point of interest Item finding Real-Time Indoor positioning Proximity marketing More advanced item Locationing Systems finding solutions (RTLS) Positioning systems Proximity solutions

  9. Slide 9: Bluetooth qualification

    © Nordic Semiconductor Bluetooth qualification  nRF Connect Bluetooth Host qualified with Direction Finding support for tag 2.1.0  Bluetooth Host QDID  SoftDevice Controller subsystem qualified for AoA transmitter since tag 2.0.0  SoftDevice QDID  Zephyr Controller Subsystem qualified for Direc

  10. Slide 10: Angle of Arrival (AoA) and Angle of Departure (AoD)

    Angle of Arrival (AoA) and Angle of Departure (AoD) 10

  11. Slide 11: Angle of Arrival (AoA)

    © Nordic Semiconductor Angle of Arrival (AoA) Transmitter  Simple beacon  Single antenna required  No I/Q calculations needed  Low cost, low power consumption device possible Receiver  Antenna array and RF switches required  I/Q data needed for angle estimation  Processing power to calculate

  12. Slide 12: Angle of Departure (AoD)

    © Nordic Semiconductor Angle of Departure (AoD) Transmitter  Advanced beacon  Antenna array and RF switches required  No I/Q calculations needed  Medium cost, low power consumption device Receiver  Single antenna  I/Q data needed for angle estimation  Processing power to calculate angles/conn

  13. Slide 13: The physics behind direction finding

    The physics behind direction finding 13

  14. Slide 14: Constant Tone Extension (CTE)

    © Nordic Semiconductor Constant Tone Extension (CTE)  CTE provides constant frequency signal for IQ sampling  Unwhitened sequence of 1s (Tone) and is appended after CRC  Connectionless and connection-oriented modes  In connectionless, periodic advertising is required (deterministic timing)  Sup

  15. Slide 15: Constant Tone Extension and I/Q sampling

    © Nordic Semiconductor Constant Tone Extension and I/Q sampling  CTE range: 16 us to 160 us  Minimum 2 antennas, maximum 38/75 antennas (switch and slot length dependent)  Guard Period – antenna may switch  Reference Period – 8 reference I/Q samples  Switch/Sample slots are 2us or 1us:  Switch

  16. Slide 16: Antenna array example – patch antennas

    © Nordic Semiconductor Antenna array example – patch antennas  12 patch antennas  High-performance RF switches 11 12 1 2  HW will scan through antennas in pre-defined patterns 10 3  one antenna set as a reference 20 cm  Array design will give 2 angles 9 4  “Line” antenna design will give 1 ang

  17. Slide 17: Antenna array – Area of coverage

    © Nordic Semiconductor Antenna array –Area of coverage  Hemisphere above the plane is covered  Performance degradation close to plane  Noticeable from about 15°  Caused by patch antenna radiation pattern 17

  18. Slide 18: Input signal with theoretical values

    © Nordic Semiconductor Input signal with theoretical values  Using antenna 1 as a reference  Transmitter 1 cm above antenna 1  2 Mbps  8 samples reference  Last sample @11 µs  Perfect 500 kHz constant tone  All antennas will have constant phase due to 18 under-sampling

  19. Slide 19: Input signal with frequency offset

    © Nordic Semiconductor Input signal with frequency offset  Using antenna 1 as a reference  Transmitter 1 cm above antenna 1  2 Mbps  8 samples reference  Last sample @11 µs  Constant tone will not be 500 kHz  Phase shifting slowly due to under-sampling 19

  20. Slide 20: Input signal from all antennas

    © Nordic Semiconductor Input signal from all antennas  Using antenna 1 as a reference  Transmitter 1 cm above antenna 1  2 Mbps  8 samples reference  Last sample @11 µs  Constant tone will not be 500 kHz  Phase shifting slowly due to under-sampling 20

  21. Slide 21: Input signal from selected antennas

    © Nordic Semiconductor Input signal from selected antennas  Using antenna 1 as a reference  Transmitter 1 cm above antenna 1  2 Mbps  8 samples reference  Last sample @11 µs  Signal will not look like a sine as each sample is for a separate antenna 21

  22. Slide 22: Phase of input signal from selected antennas

    © Nordic Semiconductor Phase of input signal from selected antennas  Displaying phase shift of input signal compared to reference  Reference period used to find frequency and phase of input signal 22

  23. Slide 23: Input signal from all antennas

    © Nordic Semiconductor Input signal from all antennas  Using antenna 1 as a reference  Transmitter 1 cm above antenna 1  2Mbps  8 samples reference  Last sample @11 µs  Constant tone will not be 500 kHz  Phase shifting slowly due to under-sampling 23

  24. Slide 24: Input signal from all antennas

    © Nordic Semiconductor Input signal from all antennas  Using antenna 1 as a reference  Transmitter 100 cm above antenna 1  2 Mbps  8 samples reference  Last sample @11 µs  Phase shift smaller due to increased distance 24

  25. Slide 25: Input signal from all antennas

    © Nordic Semiconductor Input signal from all antennas  Using antenna 1 as reference  Transmitter 1000 cm above antenna 1  2 Mbps  8 samples reference  Last sample @11 µs  Phase shift imperceptible due to increased distance 25

  26. Slide 26: IQ samples, what are they and how to use them

    IQ samples, what are they and how to use them

  27. Slide 27: What is Phase?

    © Nordic Semiconductor «What is Phase?» https://en.wikipedia.org/wiki/Phase_(waves)#/media/File:Phase_shifter_using_IQ_modulator.gif

  28. Slide 28: Conversion and Bluetooth format

    © Nordic Semiconductor Conversion and Bluetooth format  To convert from I/Q data to phase and amplitude 𝑄𝑄  Phase: 𝜃𝜃 = 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝐼𝐼  Amplitude: 𝐴𝐴 = 𝐼𝐼2 + 𝑄𝑄 2  Bluetooth spec states I/Q data should be 8 bit  Signal has to be truncated in nRF devices, normally max…

  29. Slide 29: Bluetooth 5.1 Direction finding spec

    Bluetooth 5.1 Direction finding spec

  30. Slide 30: Bluetooth specification

    © Nordic Semiconductor Bluetooth specification  Covers  Does not cover  Host functionality  Antenna array design  HCI commands  Algorithms for calculating angles  On-air packet format  Exchange of antenna array design  Sample timing  Locationing  I/Q data format  What packets can have CT

  31. Slide 31: Periodic advertising

    © Nordic Semiconductor Periodic advertising  CTE can only be appended to packets in the data channels  For non-connected Bluetooth Direction Finding it is thus mandated to use periodic advertising for the packets with CTE 31

  32. Slide 32: Triangulation

    © Nordic Semiconductor Triangulation  Utilize multiple anchor points at known position  Measure angle from all anchor points to Device  Calculate position based on data  Requires accurate and stable angle measurement  Supported by AoA and AoD Direction Finding since Bluetooth 5.1 32

  33. Slide 33: Asset tracking - RTLS

    © Nordic Semiconductor Asset tracking - RTLS  Tag is a simple transmitter  Majority of devices is the lowest-cost unit  Low power operation  Multiple AoA locators at fixed locations reporting angles  The location engine determines the position of the tag based on angle data from multiple locato

  34. Slide 34: nRF Connect SDK samples for Direction Finding

    nRF Connect SDK samples for Direction Finding

  35. Slide 35: nRF Connect SDK samples

    © Nordic Semiconductor nRF Connect SDK samples  Samples for  Connectionless locator  Connected locator  Connectionless beacon  Connected peripheral  All samples can be configured for AoA or for AoD  Basically, RF switches or no RF Switches

  36. Slide 36: Software architecture: Locator full solution

    © Nordic Semiconductor Software architecture: Locator full solution Cortex-M4/M33 Angle Bluetooth LE Cloud backend / Algorithm Bluetooth RADIO controller PC tool (Customer LE Host peripheral I/Q data (Bluetooth v5.1) I/Q data developed) (HCI) Customer code nRF Connect SDK 36

  37. Slide 37: Angle computation – essential components

    © Nordic Semiconductor Angle computation – essential components Algorithm Bluetooth LE F+P controller + Antenna Filter Calc correc host array I/Q samples ANT Calculated (incl PHY) angle Antenna Antenna Dependency! calibration model data 37

  38. Slide 38: Supported HW for Direction Finding

    Supported HW for Direction Finding

  39. Slide 39: Supported HW for Direction Finding

    © Nordic Semiconductor Supported HW for Direction Finding  Devices supported for AoA &AoD transmitter functionality  nRF52811  nRF52820  nRF52833 – Fully qualified HW and SW solution  nRF5340  Devices supported for AoA &AoD receiver  nRF52833 – Fully qualified HW and SW solution  nRF5340  R

  40. Slide 40: Nordic Partner support for Direction Finding

    Nordic Partner support for Direction Finding

  41. Slide 41: InsightSiP antenna array – patch antennas

    © Nordic Semiconductor InsightSiP antenna array – patch antennas  12 patch antennas  Design available from Nordic Devzone  Antenna array designed by Nordic, manufactured by InsightSiP  nRF52833 module mounted directly on antenna board 41

  42. Slide 42: u-blox antenna array – patch antennas

    © Nordic Semiconductor u-blox antenna array – patch antennas  4 patch antennas  u-blox antenna design  nRF52833 based  u-blox angle algorithm  u-blox multi locator SW solution available 42

  43. Slide 43: u-blox partner webinar

    © Nordic Semiconductor u-blox partner webinar  U-blox will hold a webinar on this platform 12th of December  Covering how they extend the HW & SW offering from Nordic to include  u-blox designed antenna arrays  u-blox developed angle resolution algorithms  u-blox indoor positioning engine suppo

  44. Slide 44: Thanks! Time for Q&A

    © Nordic Semiconductor Thanks! Time for Q&A 44

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