User`s guide

FIR Interpolation

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Latency

Zero Latency. The FIR Interpolation block has zero tasking latency for all

single-rate operations. The block is single-rate for the particular combinations

of sampling mode and parameter settings shown in the table below.

Note that in sample-based mode, single-rate operation occurs only in the trivial

case of factor-of-1 interpolation.

The block also has zero latency for sample-based multirate operations in

Simulink’s single-tasking mode. Zero tasking latency means that the block

propagates the first filtered input (received at t=0) as the first input sample,

followed by L-1 interpolated values, the second filtered input sample, and so

on.

Nonzero Latency. The FIR Interpolation block is multirate for all settings other

than those in the above table. The amount of latency for multirate operation

depends on Simulink’s tasking mode and the block’s sampling mode, as shown

in the table below.

In cases of one-sample latency, a zero initial condition appears as the first

output sample in each channel, followed immediately by the first filtered input

sample, L-1 interpolated values, and so on.

In cases of one-frame latency, the first M

output rows contain zeros, where M

is the input frame size. The first filtered input sample (first filtered row of the

Sampling Mode Parameter Settings

Sample-based Interpolation factor parameter, L, is 1.

Frame-based

Interpolation factor parameter, L, is 1, or

Framing parameter is Maintain input frame rate.

Multirate... Sample-Based Latency Frame-Based Latency

Single-tasking

None One frame (M

samples)

Multitasking

One sample One frame (M

samples)