[SOLVED] How to get CIR from out of an energy detector

In the context of Ultra Wideband, an Energy Detector (ED) collects energy (which is just amplitude squared) from within what they call "integration window". By the time everything is done, we only have a single numeric value, and we we use some kind of threshold to decide whether that is sufficient to call it a "1" or a "0".

Say there were two points involved , Rx and Tx for the receiver and the transmitter.
How do I come up with an expression for Channel Impulse Response (CIR) between those two points. A CIR has various amplitudes (y axis) for corresponding time delays (x-axis).

Please somebody tell me how to start with an ED and arrive at CIR.

Background: I want to CIR ("fingerprints") from various points and based on fingerprint matching, I want to be able to decide which signal is coming from which area. Since the environment I am thinking is rich in multipath, I thought I would get by with ED/OOk combination. But ED would only give me yes/no type answer. I need to have a receiver mechanism so that I can extract CIR out of that.

Thanks.

Your Rx samples are the result of convolution of Tx samples and the CIR.

Spectrum of Rx signal is an element-wise multiplication of Tx spectrum and channel frequency response (CFR).
CFR is a result of a furier transform of CIR.

So you can find your CIR by the following way:
Perform the FFT of Rx samples
Perform the FFT of Tx samples
Divide Rx/Tx element-wise.
Perform the inverse FFT of result.
You will get your CIR.
Generally tis will be a vector of complex samples.

I guess you can do nothing with your energy detector, 'cause it stores only magnitude squared, but for CIR estimation you need complex samples of Rx signal, i.e. magnitudes with phase or IQ representation

Thank you, Mityan.
You made may day.
I will have to abandon the idea of using CIR then. I need to use ED because the environment I am thinking is heavy with multipath and scattering.
Cheers.