User`s guide

3 Working with Signals
3-26
The Buffer block preserves the signal’s data and sample period only when its
Buffer overlap parameter is set to 0. The output frame period, T
fo
, is
where T
fi
is the input frame period, M
i
is the input frame size, and M
o
is the
output frame size specified by the
Buffer size parameter.
The Unbuffer block is specialized for completely unbuffering a frame-based
signal to its sample-based equivalent, and always preserves the signal’s data
and sample period:
where T
fi
and M
i
are the period and size, respectively, of the frame-based input.
Both the Buffer and Unbuffer blocks preserve the sample period of the
sequence in the conversion (T
so
=T
si
).
Example: Buffering with Preservation of the Signal. In the model below, a signal with
a sample period of 0.125 seconds is rebuffered from a frame size of 8 to a frame
size of 16. This doubles the frame period from 1 to 2 seconds, but does not
change the sample period of the signal (T
so
=T
si
= 0.125).
Buffering with Alteration of the Signal. Some forms of buffering alter the signal’s
data or sample period, in addition to adjusting the frame size. There are many
instances when this type of buffering is desirable, for example when creating
sliding windows by overlapping consecutive frames of a signal, or selecting a
subset of samples from each input frame for processing.
The blocks that alter a signal while adjusting its frame size are listed below. In
this list, T
si
is the input sequence sample period, and T
fi
and T
fo
are the input
and output frame periods, respectively.
T
fo
M
o
T
fi
M
i
----------------=
T
so
T
fi
M⁄
i
=