User`s guide

Upsample
5-484
5Upsample
Purpose Resample an input at a higher rate by inserting zeros.
Library Signal Operations
Description The Upsample block resamples each channel of the M
i
-by-N input at a rate
L times higher than the input sample rate by inserting L-1 zeros between
consecutive samples. The integer L is specified by the
Upsample factor
parameter. The
Sample offset parameter delays the output samples by an
integer number of sample periods D, where 0 ≤ D < (L-1), so that any of the L
possible output phases can be selected.
Sample-Based Operation
When the input is sample-based, the block treats each of the M∗N matrix
elements as an independent channel, and upsamples each channel over time.
The
Frame-based mode parameter must be set to Maintain input frame size.
The output sample rate is L times higher than the input sample rate
(T
so
=T
si
/L), and the input and output sizes are identical.
Frame-Based Operation
When the input is frame-based, the block treats each of the N input columns as
a frame containing M
i
sequential time samples from an independent channel.
The block upsamples each channel independently by inserting L-1 rows of
zeros between each row in the input matrix. The
Frame-based mode
parameter determines how the block adjusts the rate at the output to
accommodate the added rows. There are two available options:
•
Maintain input frame size
The block generates the output at the faster (upsampled) rate by using a
proportionally shorter frame period at the output port than at the input port.
For upsampling by a factor of L, the output frame period is L times shorter
than the input frame period (T
fo
=T
fi
/L), but the input and output frame
sizes are equal.
The model below shows a single-channel input with a frame period of
1 second being upsampled by a factor of 4 to a frame period of 0.25 seconds.
The input and output frame sizes are identical.