In free space the speed of the signal in form of electromagnetic wave is the speed of light which is the speed of propagation.

But i think you mean to calculate the bit rate or the symbol rate.

For this you use the Shannon limit of the channel capacity

C= w log2(1 +S/N ), w is the bandwidth and N is the noise of the receiver.

Here the signal power S is the received power = Th transmitted power/4pi R^2,

where R is the distance between the two antennas provided that the two antennas are in light of site.

Best wishes

The FFT will produce an amplitude and a phase spectrum.

You can estimate the distance by examining the phase.

The relationship between (group) delay and phase is explained in the initial part of my lecture notes attached.

Of course you need to think and understand what you are doing. I suggest setting up an experiment to confirm whatever calculations you do... and remember that 'c' is big, so small errors in the estimation of phase will cause errors on the estimation of the distance.

Have fun :-)

In free space the speed of the signal in form of electromagnetic wave is the speed of light which is the speed of propagation.

But i think you mean to calculate the bit rate or the symbol rate.

For this you use the Shannon limit of the channel capacity

C= w log2(1 +S/N ), w is the bandwidth and N is the noise of the receiver.

Here the signal power S is the received power = Th transmitted power/4pi R^2,

where R is the distance between the two antennas provided that the two antennas are in light of site.

Best wishes

Thanks very much, sir Abdelhalim abdelnaby Zekry. Your answer is really helpful in understanding both the concepts.