DW1000 User Manual
© Decawave Ltd 2017
Version 2.12
Page 218 of 242
Bit 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
R1
R0
L6
L5
L4
L3
L2
L1
L0
RNG
EXT
P1
P0
C5
C4
C3
C2
C1
C0
Data Rate
Frame Length
Ran
ging
Pa
cket
H
ead
er
Ext
en
sion
Preamble
Duration
SECDED Check Bits
Figure 33: PHR bit assignment
Figure 33 above shows the bits of the PHR. These are transmitted bit-0 first in time. The DW1000 fills in the
Data Rate, Frame Length, Ranging Packet, and Preamble Duration fields of the PHR based on the user
configuration of the appropriate parameters in
Register file: 0x08 – Transmit Frame Control
the SECDED sequence accordingly. The Header Extension bit of the PHR is always zero and is reserved by
IEEE for future extensions.
10.5 UWB channels and preamble codes
The IEEE 802.15.4 UWB PHY has 16 defined channel/bands. The DW1000 supports the subset of these listed
in Table 61 below. Depending on the channel and the pulse repetition frequency (PRF) the IEEE 802.15.4
UWB PHY standard defines a choice of two or four preamble codes. The standard defined preamble code
options are also listed in Table 61. The combination of channel number and preamble code gives what the
standard terms a
complex channel
.
The DW1000 does not physically impose the channel code selection, so it is up to the software to select the
appropriate preamble code for the selected operating channel. The standard notes that wideband channels
may also employ the codes allocated to the narrower 499.2 MHz bandwidth channels if inter-channel
communication is desired.
Table 61: DW1000 supported UWB channels and recommended preamble codes
Channel
number
Centre
frequency
(MHz)
Bandwidth
(MHz)
Preamble Codes
(16 MHz PRF)
Preamble Codes
(64 MHz PRF)
1
3494.4
499.2
1, 2
9, 10, 11, 12
2
3993.6
499.2
3, 4
9, 10, 11, 12
3
4492.8
499.2
5, 6
9, 10, 11, 12
4
3993.6
1331.2
*
7, 8
17, 18, 19, 20
5
6489.6
499.2
3, 4
9, 10, 11, 12
7
6489.6
1081.6
*
7, 8
17, 18, 19, 20
N.B.
For correct operation of the DW1000 the software must take care to only allow
selection of those preamble codes appropriate for the configured PRF.
* The DW1000 has a maximum receive bandwidth of 900 MHz
The preamble codes specified by the standard for use on a particular channel were chosen to have a low
cross correlation factor with each other with the intention that the complex channels could to operate
independently from each other as separate networks. In practice, as there is still a small amount of cross
correlation, there will be some break-through between different codes especially in conditions of close