SbComplexFIRvl

Overview

Sub-band Complex FIR Filter with module

Discussion

Part of DSP Concepts IP for implementing long FIR filters in the frequency domain. This module implements a complex FIR filter within each subband of a filterbank with variable length of taps per subband. At instantiation time, you specify the number of taps in each complex filter

The module allocates memory for the complex FIR coefficients and state variables and at run-time implements the complex convolutions

Module Pack

Advanced

ClassID

classID = 1323

Type Definition

typedef struct _ModuleSbComplexFIRvl
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
INT32 numWords;                               // Length of state and coeffs array
INT32* stateIndex;                            // State index per subband
INT32* numTaps;                               // Array of number of taps per subband
FLOAT32* state;                               // FIR filter state memory
FLOAT32* coeffs;                              // FIR filter coeffs array
} ModuleSbComplexFIRvlClass;

Variables

Properties

Name	Type	Usage	isHidden	Default Value	Range
numWords	int	const	1	2048	Unrestricted
stateIndex	int*	state	1	[32 x 1]	Unrestricted
numTaps	int*	parameter	0	[32 x 1]	Unrestricted
state	float*	state	1	[4096 x 1]	Unrestricted
coeffs	float*	parameter	0	[4096 x 1]	Unrestricted

Pins

Input Pins


Name	in
Description	complex input
Data type	float
Channel range	1
Block size range	Unrestricted
Sample rate range	Unrestricted
Complex support	Complex

Output Pins


Name	out
Description	complex output
Data Type	float

Matlab Usage

File Name: sb_complex_fir_vl_module.m 
 M = sb_complex_fir_vl_module(NAME, NUMWORDS, NUMSUBBANDS) 
 Creates a module which perform complex FIR filtering with variable length taps per subband. 
 The module operates on complex subband data.  Arguments: 
    NAME - name of the module. 
    NUMWORDS - Total number of complex data words in state and coefficients. 
               By default equals 2048. 
    NUMSUBBANDS - optional argument which sets the default number of subbands. 
              By default, NUMSUBBANDS = 256 and it will be overwritten in pre-build 
              function. 

 This module is part of DSPC IP for efficient fast convolution.