ASN7 - Sampled half of signal: Difference between revisions

From Class Wiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 8: Line 8:
A rule of thumb for proper sampling is to sample range slightly greater than the range of the signal. Suppose however,you sampled only half of the signal can you do something to recover the whole original signal again?
A rule of thumb for proper sampling is to sample range slightly greater than the range of the signal. Suppose however,you sampled only half of the signal can you do something to recover the whole original signal again?


1. Lets imagine that from our the result of our sampling we measured the positive and the negative part of the signal seperately. [Assume the original signal was centered at zero such that <math> f_{tot}= f_{-}+f_{+}]</math>
1. Lets imagine that from our the result of our sampling we measured the positive and the negative part of the signal seperately. [Assume the original signal was centered at zero such that <math> f_{tot}= f_{-}+f_{+} \!</math>




Line 19: Line 19:




The result of this second sampling are a number of copies of the original signal <math>nf_{tot} </math> .
The result of this second sampling are a number of copies of the original signal <math>nf_{tot} \!</math> .





Revision as of 13:32, 20 December 2009

Back to home page


Can you retrieve an original signal from a sample of range ?


A rule of thumb for proper sampling is to sample range slightly greater than the range of the signal. Suppose however,you sampled only half of the signal can you do something to recover the whole original signal again?

1. Lets imagine that from our the result of our sampling we measured the positive and the negative part of the signal seperately. [Assume the original signal was centered at zero such that


So we have repeated on the negative axis the -f and the positive axis +f.

The trick now is to re-sample at a frequency that will place the negative and positive half side by side.


2. Find the right frequency and sample again.


The result of this second sampling are a number of copies of the original signal .


3. finally, to get just one copy of the original signal apply a band pass filter.