NCO Class Reference

#include <nco.h>

Public Member Functions
	NCO ()
void	setFreq (Real freq, Real sampleRate)
void	setPhase (int phase)
void	nextPhase ()
Real	next ()
	Return next real sample. More...
Complex	nextIQ ()
	Return next complex sample. More...
Complex	nextQI ()
	Return next complex sample (reversed) More...
void	nextIQMul (Real &i, Real &q)
	multiply I,Q separately with next sample More...
Real	get ()
	Return current real sample (no phase increment) More...
Complex	getIQ ()
	Return current complex sample (no phase increment) More...
void	getIQ (Complex &c)
	Sets to the current complex sample (no phase increment) More...
Complex	getQI ()
	Return current complex sample (no phase increment, reversed) More...
void	getQI (Complex &c)
	Sets to the current complex sample (no phase increment, reversed) More...

Private Types
enum	{ TableSize = (1 << 12) }

Static Private Member Functions
static void	initTable ()

Private Attributes
int	m_phaseIncrement
int	m_phase

Static Private Attributes
static Real	m_table [TableSize]
static bool	m_tableInitialized = false

Detailed Description

Definition at line 25 of file nco.h.

Member Enumeration Documentation

anonymous enum

anonymous enum

private

Enumerator
TableSize

Definition at line 27 of file nco.h.

         {
        TableSize = (1 << 12),
    };

Constructor & Destructor Documentation

NCO()

NCO::NCO

(

)

Definition at line 42 of file nco.cpp.

References initTable(), m_phase, and m_phaseIncrement.

{
    initTable();
    m_phase = 0;
    m_phaseIncrement = 0;
}

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Member Function Documentation

get()

float NCO::get

(

)

Return current real sample (no phase increment)

Definition at line 84 of file nco.cpp.

References m_phase, and m_table.

{
    return m_table[m_phase];
}

getIQ() [1/2]

Complex NCO::getIQ

(

)

Return current complex sample (no phase increment)

Definition at line 89 of file nco.cpp.

References m_phase, m_table, and TableSize.

{
    return Complex(m_table[m_phase], -m_table[(m_phase + TableSize / 4) % TableSize]);
}

getIQ() [2/2]

void NCO::getIQ

(

Complex &

c

)

Sets to the current complex sample (no phase increment)

Definition at line 94 of file nco.cpp.

References m_phase, m_table, and TableSize.

{
    c.real(m_table[m_phase]);
    c.imag(-m_table[(m_phase + TableSize / 4) % TableSize]);
}

getQI() [1/2]

Complex NCO::getQI

(

)

Return current complex sample (no phase increment, reversed)

Definition at line 100 of file nco.cpp.

References m_phase, m_table, and TableSize.

{
    return Complex(-m_table[(m_phase + TableSize / 4) % TableSize], m_table[m_phase]);
}

getQI() [2/2]

void NCO::getQI

(

Complex &

c

)

Sets to the current complex sample (no phase increment, reversed)

Definition at line 105 of file nco.cpp.

References m_phase, m_table, and TableSize.

{
    c.imag(m_table[m_phase]);
    c.real(-m_table[(m_phase + TableSize / 4) % TableSize]);
}

initTable()

void NCO::initTable ( )

staticprivate

Definition at line 31 of file nco.cpp.

References cos(), i, M_PI, m_table, m_tableInitialized, and TableSize.

Referenced by NCO().

{
    if(m_tableInitialized)
        return;

    for(int i = 0; i < TableSize; i++)
        m_table[i] = cos((2.0 * M_PI * i) / TableSize);

    m_tableInitialized = true;
}

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next()

float NCO::next

(

)

Return next real sample.

Definition at line 55 of file nco.cpp.

References m_phase, m_table, and nextPhase().

{
    nextPhase();
    return m_table[m_phase];
}

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nextIQ()

Complex NCO::nextIQ

(

)

Return next complex sample.

Definition at line 61 of file nco.cpp.

References m_phase, m_table, nextPhase(), and TableSize.

Referenced by LoRaDemod::feed(), WFMDemod::feed(), AMDemod::feed(), DSDDemod::feed(), UDPSink::feed(), NFMDemod::feed(), BFMDemod::feed(), DATVDemod::feed(), ATVDemod::feed(), UDPSource::pull(), AMMod::pull(), WFMMod::pull(), NFMMod::pull(), and ATVMod::pullFinalize().

{
    nextPhase();
    return Complex(m_table[m_phase], -m_table[(m_phase + TableSize / 4) % TableSize]);
}

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nextIQMul()

void NCO::nextIQMul	(	Real &	i,
		Real &	q
	)

multiply I,Q separately with next sample

Definition at line 73 of file nco.cpp.

References i, m_phase, m_table, nextPhase(), and TableSize.

{
    nextPhase();
    Real x = i;
    Real y = q;
    const Real& u = m_table[m_phase];
    const Real& v = -m_table[(m_phase + TableSize / 4) % TableSize];
    i = x*u - y*v;
    q = x*v + y*u;
}

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nextPhase()

void NCO::nextPhase ( )

inline

Definition at line 44 of file nco.h.

References i.

Referenced by next(), nextIQ(), nextIQMul(), and nextQI().

    {
        m_phase += m_phaseIncrement;
        while(m_phase >= TableSize)
            m_phase -= TableSize;
        while(m_phase < 0)
            m_phase += TableSize;
    }

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nextQI()

Complex NCO::nextQI

(

)

Return next complex sample (reversed)

Definition at line 67 of file nco.cpp.

References m_phase, m_table, nextPhase(), and TableSize.

{
    nextPhase();
    return Complex(-m_table[(m_phase + TableSize / 4) % TableSize], m_table[m_phase]);
}

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setFreq()

void NCO::setFreq	(	Real	freq,
		Real	sampleRate
	)

Definition at line 49 of file nco.cpp.

References m_phaseIncrement, and TableSize.

Referenced by WFMDemod::applyChannelSettings(), AMDemod::applyChannelSettings(), UDPSink::applyChannelSettings(), UDPSource::applyChannelSettings(), NFMDemod::applyChannelSettings(), DSDDemod::applyChannelSettings(), BFMDemod::applyChannelSettings(), WFMMod::applyChannelSettings(), AMMod::applyChannelSettings(), NFMMod::applyChannelSettings(), DATVDemod::applyChannelSettings(), ATVMod::applyChannelSettings(), DATVDemod::applySettings(), ATVDemod::applySettings(), LoRaDemod::handleMessage(), LoRaDemod::LoRaDemod(), and UDPSink::UDPSink().

{
    m_phaseIncrement = (freq * TableSize) / sampleRate;
    qDebug("NCO freq: %f phase inc %d", freq, m_phaseIncrement);
}

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setPhase()

void NCO::setPhase ( int  phase )

inline

Definition at line 42 of file nco.h.

{ m_phase = phase; }

Member Data Documentation

m_phase

int NCO::m_phase

private

Definition at line 36 of file nco.h.

Referenced by get(), getIQ(), getQI(), NCO(), next(), nextIQ(), nextIQMul(), and nextQI().

m_phaseIncrement

int NCO::m_phaseIncrement

private

Definition at line 35 of file nco.h.

Referenced by NCO(), and setFreq().

m_table

Real NCO::m_table

staticprivate

Definition at line 30 of file nco.h.

Referenced by get(), getIQ(), getQI(), initTable(), next(), nextIQ(), nextIQMul(), and nextQI().

m_tableInitialized

bool NCO::m_tableInitialized = false

staticprivate

Definition at line 31 of file nco.h.

Referenced by initTable().

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

• sdrbase/dsp/nco.h
• sdrbase/dsp/nco.cpp