I am working on building a relatively small scale for cheap sports tracking. I am looking to start at an MVP of 3-4 anchors with 10 tags and then, if successful, scaling to a maximum of 8-10 anchors with 100 tags.
My plan is the use he DWM1004C for tags and DWM1001 (from the MDEK) + RaspPi for Anchors.
In terms of designing the system, there seem to be 2 big complexities by doing TDoA: Time Sync and backhaul.
- DW1001 will receive pulses, convert to tag signature and digitally pass to raspPi for timestamping.
- RaspPi will be equipped with RTC/TCXO module
- Time sync messages will happen over UWB waves.
- Aiming for <5ns precision
- Most systems seem to use Ethernet for backhaul but I find this prohibitive for many outdoor settings
- Our most-expensive case backhaul would be (100 tags)(10 pulses/second/tag)(100bits/pulse)*(10 anchors) = 1Mbps received by the server.
- This should be achievable via Wifi/BLE5 in the raspPi
We plan to write all the multilateration and time sync algos ourselves.
Does anyone have any feedback or problems they see with this design? I am most worried about Time Sync since that is what seems to be the prohibitive part about TDoA systems.