Input-Output Multipath Channel Functions The presence of multipath can be formally described by the some proper "1/O Channel Functions"that can be associated with the radio channel hpl-discrete channel:N,rays/paths hp2-static channel:channel properties don't vary in time>terminals don't move (in practice,fluctuations in time can be neglected during transmission) x() y(t)? H(f),h(t) u(t) H();h() v(t)? The I/O channel functions establish a correspondence between the input and the output signals,i.e.formulates the effects of the environment on the propagating signalInput-Output Multipath Channel Functions  The presence of multipath can be formally described by the some proper “I/O Channel Functions” that can be associated with the radio channel  hp1 - discrete channel: Nr rays/paths hp2- static channel: channel properties don’t vary in time  terminals don’t move (in practice, fluctuations in time can be neglected during transmission) H(f), h(t) H+(f) ; h0(t) y(t) ??  The I/O channel functions establish a correspondence between the input and the output signals, i.e. formulates the effects of the environment on the propagating signal v(t) ?? x(t) u(t)