User`s guide

FIR Decimation
5-194
•Maintain input frame size
The block generates the output at the slower (decimated) rate by using a
proportionally longer frame period at the output port than at the input port.
For decimation by a factor of K, the output frame period is K times longer
than the input frame period (T
fo
=KT
fi
), but the input and output frame
sizes are equal.
The example below shows a single-channel input with a frame period of 1
second (
Sample time = 1/64 and Samples per frame = 64 in the Signal
From Workspace block) being decimated by a factor of 4 to a frame period of 4
seconds. The input and output frame sizes are identical.
•
Maintain input frame rate
The block generates the output at the slower (decimated) rate by using a
proportionally smaller frame size than the input. For decimation by a factor
of K, the output frame size is K times smaller than the input frame size
(M
o
=M
i
/K), but the input and output frame rates are equal. The input frame
size,M
i
, must be a multiple of the decimation factor,K.
The example below shows a single-channel input of frame size 64 being
decimated by a factor of 4 to a frame size of 16. The block’s input and output
frame rates are identical.