User`s guide

3 Working with Signals
3-30
The Vector Scope block uses the input frame size (128) and period (12.8) to
deduce the original signal’s sample period (0.1), which allows it to correctly
display the peaks at 1 Hz and 2 Hz.
Example 2: Unintended Rate Conversion. Now alter the previous example by setting
the Magnitude FFT block parameters as follows:
•Deselect the
Inherit FFT length from input dimensions check box.
•Set the
FFT length parameter to 256.
This setting instructs the block to zero-pad the length-128 input frame to a
length of 256 before performing the FFT. The signal dimension display on the
new version of the model shows that the output of the Magnitude FFT block is
now a length-256 frame.
The plot generated by the Vector Scope block is shown below.