DW1000 TWR calculator question

Hello,

I set up the following parameters in the power calculator tool :

Channel : 7
Data Rate : 110 Kbps
Preamble Length : 4096 symbols (same as bytes ?)
PRF : 64
Bytes : 10

The application gave me the following timing :

Preamble duration 4133.33 us, so it means 0.99 us / symbole(4133.33 / (4096+64)).
Payload duration 1222.56 us, 81 us / byte (1222.56/10).

If symboles are the same as bytes, then I don’t really understand how the calculation was done !

Can you please provide more details on this

Thank you

Any clarification ?

please study IEEE 802.15.4 standard (UWB PHY) and DW1000 Data Sheet.

Thank you Zoran Skrba for your answer,

I Already did and couldn’t find an answer for my question.

Based on the IEEE 802.15.4 standard : https://www.iith.ac.in/~tbr/teaching/docs/802.15.4-2003.pdf

6.3.1.1 Preamble field
The preamble field is used by the transceiver to obtain chip and symbol synchronization with an incoming message. The preamble field shall be composed of 32 binary zeros.

Another paper doesn’t distinguish between symbols and bytes when describing the UWB PHY frame structure. Link, page 48 : http://newton.ee.auth.gr/pavlidou/papers/J075.pdf

Please, Advice if you have any further information or specific documents to clarify this.

Chaabane
Regards

For UWB, preamble symbols have nothing to do with bytes
refer to section 16.2.5.1 (SYNC field of UWB PHY) of IEEE 802.15.4-2015
or alternatively to the DW1000 user manual section 10.3 Synchronisation header modulation scheme
Although less detailed, the paper you mentionned properly describes UWB preamble symbols as a sequence of coded symbols from ternary alphabet
Fabrice