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@@ -220,5 +220,10 @@ This should look somewhat asymmetrical, like something was added to the beginnin
 
 ![image](https://user-images.githubusercontent.com/4240543/163085309-3b59b0ad-2214-43ac-b654-63cf46c3a7cb.png)
 
-You should now be able to see that the newly highlighted samples look a *lot* like the last few samples that aren't highlighted.  This feature is almost always present in OFDM systems, but isn't always this obvious.
+You should now be able to see that the newly highlighted samples look a *lot* like the last few samples that aren't highlighted.  This feature is almost always present in OFDM systems, but isn't always this obvious.  And as we will discuss later, not all OFDM symbols are symmetrical like this (special feature of this specific OFDM symbol)
 
+One other piece of knowledge about OFDM symbols: They are very commonly a power of 2 in length
+
+This isn't *always* the case, but a power of two means that a Fast Fourier Transform (FFT) can be used instead of a Discreet Fourier Transform (DFT) - the latter being more computationally expensive.
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+Taking a look at the samples in the plot from earlier we can roughly calculate the number of samples in each symbol.  This symmetrical symbol will be the easiest to work with since the boundaries of the symbol are more obvious than the others.  Looking at the MATLAB plot we can see that the left-most sample in the white box is about `7,700` and the right most is about `9,760`.  The difference of the two being `2,060` which is *very* close to `2048` which is a power of 2 (`2^11`)