Forum: GNU Radio Re: sending single tone Am modulated using usrp1+wbx

Ok, Im aware about the damage as a result of direct connection,

But now the question is How to recovery the m(t) signal in spite of 
noise?
That is, finally the I and Q in rx should be equal to I and Q in tx.

On 08 Jan 2013 13:49, José María Valencia wrote:

> Ok, I'm aware
about the damage as a result of direct connection,
>
> But now the
question is How to recovery the m(t) signal in spite of noise? That is,
finally the I and Q in rx should be equal to I and Q in tx.

The values
of I/Q at the receiver will, hopefully, be linearly-proportional to the
values as transmitted. When you use radio systems to convey
*information*, you use those signals to *encode* that information, using
modulation schemes that only require that the signals be
linearly-proportional (and sometimes not even that) to the signals as
sent. That's how radio works. You modulate information onto a carrier,
and demodulate that carrier to recover the original (or a reasonable
facsimile of the original) information.

The Universe conspires to
mangle electromagnetic waves, to a greater or lesser extent, depending
on a number of factors including wavelength, distance, interference,
etc, etc, etc. If you rely on the received signal to be *identical* to
the transmitted signal, then you are living in a conceptual state of
sin, and must revise your thinking.