SecondOrderRecursiveFilter Class Reference

#include <recursivefilters.h>

Public Member Functions
	SecondOrderRecursiveFilter (float samplingFrequency, float centerFrequency, float r)
	~SecondOrderRecursiveFilter ()
void	setFrequencies (float samplingFrequency, float centerFrequency)
void	setR (float r)
short	run (short sample)
float	run (float sample)

Private Member Functions
void	init ()

Private Attributes
float	m_r
float	m_frequencyRatio
float	m_f
float	m_v [3]

Detailed Description

: This is a second order bandpass filter using recursive method. r is in range ]0..1[ the higher the steeper the filter. inspired by:http://www.ece.umd.edu/~tretter/commlab/c6713slides/FSKSlides.pdf

Definition at line 27 of file recursivefilters.h.

Constructor & Destructor Documentation

SecondOrderRecursiveFilter()

SecondOrderRecursiveFilter::SecondOrderRecursiveFilter	(	float	samplingFrequency,
		float	centerFrequency,
		float	r
	)

Definition at line 24 of file recursivefilters.cpp.

References init().

                                                                                                              :
        m_r(r),
        m_frequencyRatio(centerFrequency/samplingFrequency),
        m_f(cos(2.0*M_PI*(m_frequencyRatio)))
{
    init();
}

Here is the call graph for this function:

~SecondOrderRecursiveFilter()

SecondOrderRecursiveFilter::~SecondOrderRecursiveFilter

(

)

Definition at line 32 of file recursivefilters.cpp.

{}

Member Function Documentation

init()

void SecondOrderRecursiveFilter::init ( )

private

Definition at line 68 of file recursivefilters.cpp.

References i, and m_v.

Referenced by SecondOrderRecursiveFilter(), setFrequencies(), and setR().

{
    for (int i = 0; i < 3; i++)
    {
        m_v[i] = 0.0f;
    }
}

Here is the caller graph for this function:

run() [1/2]

short SecondOrderRecursiveFilter::run

(

short

sample

)

Definition at line 48 of file recursivefilters.cpp.

References m_f, m_r, and m_v.

Referenced by ATVDemod::demod().

{
    m_v[0] = ((1.0f - m_r) * (float) sample) + (2.0f * m_r * m_f * m_v[1]) - (m_r * m_r * m_v[2]);
    float y = m_v[0] - m_v[2];
    m_v[2] = m_v[1];
    m_v[1] = m_v[0];

    return (short) y;
}

Here is the caller graph for this function:

run() [2/2]

float SecondOrderRecursiveFilter::run

(

float

sample

)

Definition at line 58 of file recursivefilters.cpp.

References m_f, m_r, and m_v.

{
    m_v[0] = ((1.0f - m_r) * sample) + (2.0f * m_r * m_f * m_v[1]) - (m_r * m_r * m_v[2]);
    float y = m_v[0] - m_v[2];
    m_v[2] = m_v[1];
    m_v[1] = m_v[0];

    return y;
}

setFrequencies()

void SecondOrderRecursiveFilter::setFrequencies	(	float	samplingFrequency,
		float	centerFrequency
	)

Definition at line 35 of file recursivefilters.cpp.

References cos(), init(), m_f, m_frequencyRatio, and M_PI.

Referenced by ATVDemod::applySettings().

{
    m_frequencyRatio = centerFrequency / samplingFrequency;
    m_f = cos(2.0*M_PI*m_frequencyRatio);
    init();
}

Here is the call graph for this function:

Here is the caller graph for this function:

setR()

void SecondOrderRecursiveFilter::setR

(

float

r

)

Definition at line 42 of file recursivefilters.cpp.

References init(), and m_r.

{
    m_r = r;
    init();
}

Here is the call graph for this function:

Member Data Documentation

m_f

float SecondOrderRecursiveFilter::m_f

private

Definition at line 43 of file recursivefilters.h.

Referenced by run(), and setFrequencies().

m_frequencyRatio

float SecondOrderRecursiveFilter::m_frequencyRatio

private

Definition at line 42 of file recursivefilters.h.

Referenced by setFrequencies().

m_r

float SecondOrderRecursiveFilter::m_r

private

Definition at line 41 of file recursivefilters.h.

Referenced by run(), and setR().

m_v

float SecondOrderRecursiveFilter::m_v[3]

private

Definition at line 44 of file recursivefilters.h.

Referenced by init(), and run().

---

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

• sdrbase/dsp/recursivefilters.h
• sdrbase/dsp/recursivefilters.cpp