Max distance dependence on signal parameters

Wireless Connectivity Ultra-Wideband
1

Hello everybody,
We carried out an experiment in determination of maximum operating range
of TTK 1000 system in two different modes (Table is shown below). In experiment
we moved away tag from two anchors (master and slave) step by step.We expected
to obtain greater distances in mode 2, but results of experiment (on plot below)
demonstrate that there is sharp loss of received UWB messages at almost the same
distance in both modes (what means the same maximum operating range in both
modes). Can somebody explain this result or point out our mistake? Thanks in
advance!

Mode 1 Mode 2
Channel number 2 1
Pulse Repetition Frequency (PRF), MHz 64 16
Preambule length 128 2048
Preambule code for transmission 9 32
PAC (Preambule Acquisition Chunk) 16 32
Data rate, kbit/s 6810 110

Dependence of the percentage of received UWB messages on the distance

изображение

2

What antenna height did you have above the ground?
Can you repeat this test with the antennas at a different height (ideally higher) and see what impact that has?

3

110 cm above ground

Thank you for the idea

4

You got 70 meters with the settings listed for mode 1 and 110 cm above the ground? Was this with power within the FCC limits? If so I’m impressed.

One other thing to do is keep going after you lose the signal. at around 2m on channel 4 we often see a dropout at around 60-70 meters but after that it comes back and is good out to over 100 m. This is using different settings to you but ground reflections don’t care about things like data rate.