Some question about linear fit

[Challenger1132]

@egaebel
Hi,
I have read your code about lgtm project, thank you for your efforts ! It helped me a lot.
A lot of experiments have been carried out, unfortunately，when I use my data from Intel 5300 NIC, the precision of AOA estimtion is far from satisfactory.
I noticed the process of phase sanitization algorithm which use spotfi_algorithm_1 algorithm.
I have some ideas about that. I construct a model to quantify the time delay.
τ = T_error + T_tof + T_antenna
τ represent the total time delay.
T_error represent the time delay induced by PDD、STO and other phase error.
T_tof represent thre time consumed by signal propagation from transmitter to receiver.
T_antenna represent the time consumed by signal propagation between two antennas, which can be expressed as T_antenna = (n-1)d*sinθ / c. d is the distance between two adjacent antennas and c is the speed of light.
τ_fit represent the linear fit result.
The aim of linear fit is to remove the effect of random time delay induced by PDD and STO.
when τ_fit <= T_error + T_tof, the angle information is retained.
when τ_fit fall in between T_error + T_tof and T_error + T_tof + T_antenna, I guess that the angle information will be destroy.
and, when τ_fit fall >= T_error + T_tof + T_antenna, the angle information will alse be destroy.
I want to know that whether my guess is right or not ?
Will the process of liear fit will comeout such a situation ? I call it "over" liear fit.
This question has pusseled me for a long time. I will be appreciated of you if you could give me a hand.
thank you.

[whubaichuan]

@Challenger1132 Have you down this problem?welcome to communication