IIRDecimator

Overview

Audio sample decimator with IIR filter

Discussion

The IIR decimator subsystem implements an IIR filter followed by a downsampler. IIR low-pass filter is realized by adding allpass pair subsystem output. Vaiable cutoffFreq must be smaller than Fs*0.5/D, where Fs is a sampling rate and D is a decimation factor

The block size of the input pin must be divisible by the decimation factor D. The output block size equals the input block size divided by D. The output sample rate equals the input sample rate divided by D.

Type Definition

-Not Shown-

Variables

Properties

Pins

Input Pins

Name: in

Description: Audio input

Data type: float

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: Audio input

Data type: float

Scratch Pins

Channel count: 1

Block size: 32

Sample rate: 48000

Channel count: 1

Block size: 32

Sample rate: 48000

Channel count: 1

Block size: 32

Sample rate: 48000

MATLAB Usage

File Name: iir_decimator_subsystem.m

 SYS=iir_decimator_subsystem(NAME, D)
 Create a sub-system that decimates audio samples with IIR filter(s). IIR
 filters are implemented with allpass_pair sub-system with Elliptic filter
 option.
  
 Arguments:
    NAME - name of the module.
    D - Decimation factor.
 Copyright 2018.  DSP Concepts, Inc.  All Rights Reserved.
 Author:  Taka Unno