UWB and detection of NLOS path

[kamtar]

I'm FW developer so RF is a little bit outside mine understanding. I would like to ask about details on how detection of a signal which came via NLOS is possible.

I'm talking about UWB radio (concretely decawave). From user manual, it should work by comparing first path power vs estimated RX power.
It works with that when it's a NLOS signal first path power is less than overall RX power.

I get now that when it gets reflected or diffracted then some interference happens, some frequencies are attenuated in a different way etc.. but I'm trying to understand what exactly happens, why first path signal gets attenuated more in this case?

I don't need full explanations just some hints into where to look, I went through a few of studies and other materials but wasn't able to find an answer on why just that it happens.

[rhb]

When a wave is reflected or refracted, the propagation direction changes.   For a multipath  UWB signal this means that different frequencies experience phase cancelation at any given reception location.

Think back to optics in 2nd or 3rd semester physics.  You should have encountered it in that context.

I suspect that the real problem is you're expecting it to be more complicated than it is.  Of course, if you're trying to predict it, it *is* more complicated than you think.  The reflected and direct oath single plane wave impulse is easy.  The real world gets seriously messy.

Be happy.  If this were seismic, you'd have to deal with spatially varying velocity.