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
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 | Units |
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.