Re: [Discuss-gnuradio] sending single tone Am modulated using usrp1+wbx

[mleech]

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.