About the channelsounding algorithm using nRF54L15-DK or TAG

[Hakuto]

Hi support team,

We would like to evaluate channel sounding using your evaluation board.(nRF54L15-DK and nRF54L15-TAG)

We have been able to verify channel sounding using the sample code you provided. However, we would like to learn more about the IFFT algorithm.

I was unable to find the source code that would help me understand the IFFT algorithm. We'd like to know datails of CS_DE Library.

Could you please explain the equations and algorithm for IFFT?  　Of course, sharing the source code would also OK.

Thanks,

[Pallavi Patil]

HI Hukato,

You can find the header file here: include/bluetooth/cs_de.h ans the source file here : subsys/bluetooth/cs_de.

The cs_de_ifft() computes a distance estimate using the Inverse Fast Fourier Transform method entirely from the initiator's own CS subevent result events. It is used in the CS IPT sample where the reflector's data is already encoded in the received tones. 
please let me know if you need understanding it in more details

Regards

Pallavi