DW1000 User Manual
© Decawave Ltd 2017
Version 2.12
Page 28 of 242
operating with standard frame encoding because the SECDED error check sequence of the PHR in long frame
mode is incompatible with the standard encoding.
Note also that the probability of an error occurring within a frame increases as the frame length is increased,
and as a result of this increasing the frame length may or may not improve system throughput depending on
the frame error rate and the need to retransmit frames when there is an error.
In long frame mode only the high order bit of the TXPSR value from
Register file: 0x08 – Transmit Frame
is sent in the PHR and reported in the RXPSR value in
Register file: 0x10 – RX Frame Information
The PHR encoding for the proprietary extended length data frames is shown below in Figure 12:
Figure 12 : PHR Encoding Extended Length Data Frames
The Data Rate field has the same encoding as used for the IEEE 802.15.4-2011 PHR.
The frame length field L9-L0 is an unsigned 10-bit integer number that indicates the number of octets in the
PSDU from the MAC sub-layer. Note that the high order bit of the length is transmitted first in time.
A single bit, P0, provides the Preamble Duration field, indicating the length of the SYNC portion of the SHR
shown in Table 5.
Table 5: Preamble Duration field values in Extended Length Data Frame PHR
P0
Preamble length for
BPM-BPSK modulation
mode
0
64 to 1024 symbols
1
1536 to 4096 symbols
The Preamble Duration field may be used by a receiver to set the value of the preamble duration for an ACK
frame.
Valid preamble lengths are 64, 128, 256, 512, 1024, 1536, 2048 and 4096 symbols. Since the Preamble
Duration field in the transmitted frame covers a range of preamble lengths, a receiver may count the
Bit
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
14
16
17
18
R1
R0
L9
L8
L7
L6
L5
L4
L3
L2
L1
L0
P0
S5
S4
S3
S2
S1
S0
Data
Rate
SECDED Check Bits
P
re
am
b
le
D
u
ra
tio
n
Frame Length