Signal modulation can be achieved by varying the frequency of a signal right? According to the formula as the velocity changes so does the frequency. If the wavelength of a wireless signal passes from one medium to another (say air to wall) wouldn't this change the velocity and consequently change the frequency and mess up the modulation?
I came across the concept of modulation while reading about computer networks. It was my understanding that modulation works by varying a single aspect of a wave (e.g. frequency) such that every variation has a corresponding meaning.
If a wave changes medium then it's frequency changes, correct? If a wave changes from traveling from air to a wall, wouldn't that change it's frequency and therefore corrupt the data it represents? Are you saying that the change in frequency would be insignificant?
The other thing is that the change in the signal between mediums and or Doppler is predictable and hence can be compensated for.
Also if the fractional frequency shift is small compared to the carrier the change can be negligible for most purposes.
Nothing is corrupted, the signal undrgoes a transformation process through which the original can be recovered (if it is not ignorable, or self corrected).