decaWave DW1000 - Page 8

DW1000 User Manual
© Decawave Ltd 2017
Version 2.12
Page 8 of 242
Section
No
Section Name
Information covered
9
Operational design choices when
employing the DW1000
Discusses some of the issues to be considered and trade-offs to
be made when building systems based on the DW1000
10
APPENDIX 1: The IEEE 802.15.4
UWB physical layer
Provides background information on the UWB PHY layer of the
IEEE802.15.4 standard
11
APPENDIX 2: The IEEE 802.15.4
MAC layer
Provides background information on the MAC layer of the
IEEE802.15.4 standard
12
APPENDIX 3: Two-Way Ranging
Gives an introduction to the use of the DW1000 in two-way
ranging proximity systems
13
APPENDIX 4: Abbreviations and
acronyms
Provides a list and explanation of abbreviations and acronyms
used in the rest of the document
14
APPENDIX 5: References
Lists the documents referred to in this user manual
15
Document History
Gives the revision history of this document
16
Major changes
Gives the major changes at each revision of this document
Note: Decawave also provides DW1000 device driver software as source code. This source code includes a
set of API functions to initialise, configure and control the DW1000. It provides API functions for
transmission and reception, and for driving the functionalities of the IC. The DW1000 driver source code is
targeted for the ARM cortex M3 but is readily portable to other microprocessor systems. The code comes
with a number of demo/test applications, (including a two-way ranging application), to exercise the API and
the features of the DW1000.
Clock Periods and Frequencies
The chipping rate given by the IEEE 802.15.4-2011 standard [1] is 499.2 MHz. DW1000 system clocks are
referenced to this frequency. Where the system clock frequency is given as 125 MHz, this is an
approximation to the actual system clock frequency of 124.8 MHz. Similarly, where the system clock period
is given as 8 ns, this is an approximation to the actual period of 1/ (124.8×10
6
) seconds.
The 1 GHz PLL clock, where referenced, is an approximation to its actual frequency of 998.4 MHz.
A 63.8976 GHz sampling clock is associated with ranging for the IEEE 802.15.4-2011 standard, where a 15.65
picosecond time period is referred to, it is an approximation to the period of this clock.
PRF
PRF values of 16 MHz and 64 MHz are given in this document. These are approximations to the PRF values
dictated by [1]. PRF mean values are slightly higher for SHR as opposed to the other portions of a frame.
Mean PRF values are 16.1/15.6 MHz and 62.89/62.4 MHz. Refer to [1] for full details of peak and mean
PRFs.