Finite Impulse Response (FIR) filter design functions. More...

#include <gnuradio/filter/firdes.h>

Public Types
enum	win_type { WIN_NONE = -1, WIN_HAMMING = 0, WIN_HANN = 1, WIN_BLACKMAN = 2, WIN_RECTANGULAR = 3, WIN_KAISER = 4, WIN_BLACKMAN_hARRIS = 5, WIN_BLACKMAN_HARRIS, WIN_BARTLETT = 6, WIN_FLATTOP = 7 }

Static Public Member Functions
static std::vector< float >	window (win_type type, int ntaps, double beta)

static std::vector< float >	low_pass (double gain, double sampling_freq, double cutoff_freq, double transition_width, win_type window=WIN_HAMMING, double beta=6.76)
	Use "window method" to design a low-pass FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. Window type determines maximum attenuation and passband ripple. More...

static std::vector< float >	low_pass_2 (double gain, double sampling_freq, double cutoff_freq, double transition_width, double attenuation_dB, win_type window=WIN_HAMMING, double beta=6.76)
	Use "window method" to design a low-pass FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps More attenuation –> more taps. The window type determines maximum attentuation and passband ripple. More...

static std::vector< float >	high_pass (double gain, double sampling_freq, double cutoff_freq, double transition_width, win_type window=WIN_HAMMING, double beta=6.76)
	Use "window method" to design a high-pass FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. The window determines maximum attenuation and passband ripple. More...

static std::vector< float >	high_pass_2 (double gain, double sampling_freq, double cutoff_freq, double transition_width, double attenuation_dB, win_type window=WIN_HAMMING, double beta=6.76)
	Use "window method" to design a high-pass FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps More attenuation –> more taps. The window determines maximum attenuation and passband ripple. More...

static std::vector< float >	band_pass (double gain, double sampling_freq, double low_cutoff_freq, double high_cutoff_freq, double transition_width, win_type window=WIN_HAMMING, double beta=6.76)
	Use "window method" to design a band-pass FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. The window determines maximum attenuation and passband ripple. More...

static std::vector< float >	band_pass_2 (double gain, double sampling_freq, double low_cutoff_freq, double high_cutoff_freq, double transition_width, double attenuation_dB, win_type window=WIN_HAMMING, double beta=6.76)
	Use "window method" to design a band-pass FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps. More attenuation –> more taps. Window type determines maximum attenuation and passband ripple. More...

static std::vector< gr_complex >	complex_band_pass (double gain, double sampling_freq, double low_cutoff_freq, double high_cutoff_freq, double transition_width, win_type window=WIN_HAMMING, double beta=6.76)
	Use the "window method" to design a complex band-pass FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. The window type determines maximum attenuation and passband ripple. More...

static std::vector< gr_complex >	complex_band_pass_2 (double gain, double sampling_freq, double low_cutoff_freq, double high_cutoff_freq, double transition_width, double attenuation_dB, win_type window=WIN_HAMMING, double beta=6.76)
	Use "window method" to design a complex band-pass FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps More attenuation –> more taps. Window type determines maximum attenuation and passband ripple. More...

static std::vector< float >	band_reject (double gain, double sampling_freq, double low_cutoff_freq, double high_cutoff_freq, double transition_width, win_type window=WIN_HAMMING, double beta=6.76)
	Use "window method" to design a band-reject FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. Window type determines maximum attenuation and passband ripple. More...

static std::vector< float >	band_reject_2 (double gain, double sampling_freq, double low_cutoff_freq, double high_cutoff_freq, double transition_width, double attenuation_dB, win_type window=WIN_HAMMING, double beta=6.76)
	Use "window method" to design a band-reject FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps More attenuation –> more taps. Window type determines maximum attenuation and passband ripple. More...

static std::vector< float >	hilbert (unsigned int ntaps=19, win_type windowtype=WIN_RECTANGULAR, double beta=6.76)
	design a Hilbert Transform Filter More...

static std::vector< float >	root_raised_cosine (double gain, double sampling_freq, double symbol_rate, double alpha, int ntaps)
	design a Root Cosine FIR Filter (do we need a window?) More...

static std::vector< float >	gaussian (double gain, double spb, double bt, int ntaps)
	design a Gaussian filter More...

Detailed Description

Finite Impulse Response (FIR) filter design functions.

Member Enumeration Documentation

◆ win_type

enum gr::filter::firdes::win_type

Enumerator
WIN_NONE	don't use a window
WIN_HAMMING	Hamming window; max attenuation 53 dB.
WIN_HANN	Hann window; max attenuation 44 dB.
WIN_BLACKMAN	Blackman window; max attenuation 74 dB.
WIN_RECTANGULAR	Basic rectangular window.
WIN_KAISER	Kaiser window; max attenuation a function of beta, google it.
WIN_BLACKMAN_hARRIS	Blackman-harris window.
WIN_BLACKMAN_HARRIS	alias to WIN_BLACKMAN_hARRIS for capitalization consistency
WIN_BARTLETT	Barlett (triangular) window.
WIN_FLATTOP	flat top window; useful in FFTs

Member Function Documentation

◆ band_pass()

static std::vector<float> gr::filter::firdes::band_pass	(	double	gain,
		double	sampling_freq,
		double	low_cutoff_freq,
		double	high_cutoff_freq,
		double	transition_width,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use "window method" to design a band-pass FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. The window determines maximum attenuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
low_cutoff_freq	center of transition band (Hz)
high_cutoff_freq	center of transition band (Hz)
transition_width	width of transition band (Hz).
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ band_pass_2()

static std::vector<float> gr::filter::firdes::band_pass_2	(	double	gain,
		double	sampling_freq,
		double	low_cutoff_freq,
		double	high_cutoff_freq,
		double	transition_width,
		double	attenuation_dB,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use "window method" to design a band-pass FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps. More attenuation –> more taps. Window type determines maximum attenuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
low_cutoff_freq	center of transition band (Hz)
high_cutoff_freq	center of transition band (Hz)
transition_width	width of transition band (Hz).
attenuation_dB	out of band attenuation
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ band_reject()

static std::vector<float> gr::filter::firdes::band_reject	(	double	gain,
		double	sampling_freq,
		double	low_cutoff_freq,
		double	high_cutoff_freq,
		double	transition_width,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use "window method" to design a band-reject FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. Window type determines maximum attenuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
low_cutoff_freq	center of transition band (Hz)
high_cutoff_freq	center of transition band (Hz)
transition_width	width of transition band (Hz)
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ band_reject_2()

static std::vector<float> gr::filter::firdes::band_reject_2	(	double	gain,
		double	sampling_freq,
		double	low_cutoff_freq,
		double	high_cutoff_freq,
		double	transition_width,
		double	attenuation_dB,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use "window method" to design a band-reject FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps More attenuation –> more taps. Window type determines maximum attenuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
low_cutoff_freq	center of transition band (Hz)
high_cutoff_freq	center of transition band (Hz)
transition_width	width of transition band (Hz).
attenuation_dB	out of band attenuation
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ complex_band_pass()

static std::vector<gr_complex> gr::filter::firdes::complex_band_pass	(	double	gain,
		double	sampling_freq,
		double	low_cutoff_freq,
		double	high_cutoff_freq,
		double	transition_width,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use the "window method" to design a complex band-pass FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. The window type determines maximum attenuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
low_cutoff_freq	center of transition band (Hz)
high_cutoff_freq	center of transition band (Hz)
transition_width	width of transition band (Hz)
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ complex_band_pass_2()

static std::vector<gr_complex> gr::filter::firdes::complex_band_pass_2	(	double	gain,
		double	sampling_freq,
		double	low_cutoff_freq,
		double	high_cutoff_freq,
		double	transition_width,
		double	attenuation_dB,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use "window method" to design a complex band-pass FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps More attenuation –> more taps. Window type determines maximum attenuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
low_cutoff_freq	center of transition band (Hz)
high_cutoff_freq	center of transition band (Hz)
transition_width	width of transition band (Hz)
attenuation_dB	out of band attenuation
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ gaussian()

static std::vector<float> gr::filter::firdes::gaussian	(	double	gain,
		double	spb,
		double	bt,
		int	ntaps
	)

static

design a Gaussian filter

Parameters

gain	overall gain of filter (typically 1.0)
spb	symbol rate, must be a factor of sample rate
bt	bandwidth to bitrate ratio
ntaps	number of taps

◆ high_pass()

static std::vector<float> gr::filter::firdes::high_pass	(	double	gain,
		double	sampling_freq,
		double	cutoff_freq,
		double	transition_width,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use "window method" to design a high-pass FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. The window determines maximum attenuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
cutoff_freq	center of transition band (Hz)
transition_width	width of transition band (Hz)
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ high_pass_2()

static std::vector<float> gr::filter::firdes::high_pass_2	(	double	gain,
		double	sampling_freq,
		double	cutoff_freq,
		double	transition_width,
		double	attenuation_dB,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use "window method" to design a high-pass FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps More attenuation –> more taps. The window determines maximum attenuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
cutoff_freq	center of transition band (Hz)
transition_width	width of transition band (Hz).
attenuation_dB	out of band attenuation
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ hilbert()

static std::vector<float> gr::filter::firdes::hilbert	(	unsigned int	ntaps = `19`,
		win_type	windowtype = `WIN_RECTANGULAR`,
		double	beta = `6.76`
	)

static

design a Hilbert Transform Filter

Parameters

ntaps	number of taps, must be odd
windowtype	one kind of firdes::win_type
beta	parameter for Kaiser window

◆ low_pass()

static std::vector<float> gr::filter::firdes::low_pass	(	double	gain,
		double	sampling_freq,
		double	cutoff_freq,
		double	transition_width,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use "window method" to design a low-pass FIR filter. The normalized width of the transition band is what sets the number of taps required. Narrow –> more taps. Window type determines maximum attenuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
cutoff_freq	center of transition band (Hz)
transition_width	width of transition band (Hz)
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ low_pass_2()

static std::vector<float> gr::filter::firdes::low_pass_2	(	double	gain,
		double	sampling_freq,
		double	cutoff_freq,
		double	transition_width,
		double	attenuation_dB,
		win_type	window = `WIN_HAMMING`,
		double	beta = `6.76`
	)

static

Use "window method" to design a low-pass FIR filter. The normalized width of the transition band and the required stop band attenuation is what sets the number of taps required. Narrow –> more taps More attenuation –> more taps. The window type determines maximum attentuation and passband ripple.

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
cutoff_freq	beginning of transition band (Hz)
transition_width	width of transition band (Hz)
attenuation_dB	required stopband attenuation
window	one of firdes::win_type
beta	parameter for Kaiser window

◆ root_raised_cosine()

static std::vector<float> gr::filter::firdes::root_raised_cosine	(	double	gain,
		double	sampling_freq,
		double	symbol_rate,
		double	alpha,
		int	ntaps
	)

static

design a Root Cosine FIR Filter (do we need a window?)

Parameters

gain	overall gain of filter (typically 1.0)
sampling_freq	sampling freq (Hz)
symbol_rate	symbol rate, must be a factor of sample rate
alpha	excess bandwidth factor
ntaps	number of taps

◆ window()

static std::vector<float> gr::filter::firdes::window	(	win_type	type,
		int	ntaps,
		double	beta
	)

static

The documentation for this class was generated from the following file:

firdes.h

Public Types

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ win_type

Member Function Documentation

◆ band_pass()

◆ band_pass_2()

◆ band_reject()

◆ band_reject_2()

◆ complex_band_pass()

◆ complex_band_pass_2()

◆ gaussian()

◆ high_pass()

◆ high_pass_2()

◆ hilbert()

◆ low_pass()

◆ low_pass_2()

◆ root_raised_cosine()

◆ window()