The distance measurement data using ipt_initiator demo fluctuates greatly

[666]

Hi all,

    Using two nrf54l15DK boards, v3.3.1 ncs, and ipt_initiator and ipt_ reflector demos without any modifications, in a testing environment at a distance of 5.1m, there were no obstructions between the two boards and the surroundings were relatively open. The data is as follows:

    Is it normal for the data to experience significant fluctuations and is there any way to optimize it?

    Looking forward to your reply！

[tesc]

Hi,

Those fluctuations look severe. Accuracy should typically be within half a metre. However, a limitation of the IPT sample is that results are not filtered based on quality, unlike e.g. the Bluetooth: Channel Sounding Initiator with Ranging Requestor sample which does some quality filtering. Further, for the IPT samples, the distance estimation solely uses IFFT, and so results are not combined with e.g. RTT for yielding better results. Lastly, the IPT samples only uses one antenna path.

I would, as a first step, evaluate the non-IPT Channel Sounding samples, as they do provide more options and should provide better ranging results out-of-the-box.

Regards,
Terje

[666]

Hi,

  1. Are you saying that the above test results are normal due to some limitations of IPT？
   2. Based on the above environment, I conducted the same test(5.1m) on ras_initiator(v3.3.1,two nrf54l15DK boards) and found that ifft still jumps significantly. The results are as follows:

   Is this test result normal ？Do you have any suggestions?

   Looking forward to your reply！