Is radio path chanell respone symmetry ?

[motish5]

Hello
assume I sample signal between Transmiter to Reciver T->R
Is the chanell respone would be the same to R->T also?

especially I wonder about knife difraction effect ( Fresnel zone )

 

[sophiecentaur]

You seem to be referring to the principle of 'Reciprocity' which says that a receiver and transmitter can be transposed in a link, all things being equal, and the same signal level will be received.
I think it holds good as long as you can be sure that the conditions are strictly adhered to. The diffraction situation would also hold - because every RF link involves diffraction. Sometimes it's more obvious than at other times.