dds_int.c File Reference

#include <inttypes.h>
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/complex.h"
#include "spandsp/dds.h"

Defines
#define	M_PI   3.14159265358979323846
#define	SLENK   7
#define	DDS_STEPS   (1 << SLENK)
#define	DDS_SHIFT   (32 - 2 - SLENK)
Functions
int32_t	dds_phase_rate (float frequency)
	Find the phase rate value to achieve a particular frequency.
float	dds_frequency (int32_t phase_rate)
	Find the frequency, in Hz, equivalent to a phase rate.
int	dds_scaling_dbm0 (float level)
	Find the scaling factor needed to achieve a specified level in dBm0.
int	dds_scaling_dbov (float level)
	Find the scaling factor needed to achieve a specified level in dBmov.
int16_t	dds_lookup (uint32_t phase)
	Lookup the integer value of a specified phase.
int16_t	dds_offset (uint32_t phase_acc, int32_t phase_offset)
	Find the amplitude for a particular phase offset from an accumulated phase.
void	dds_advance (uint32_t *phase_acc, int32_t phase_rate)
	Advance the phase, without returning any new signal sample.
int16_t	dds (uint32_t *phase_acc, int32_t phase_rate)
	Generate an integer tone sample.
int16_t	dds_mod (uint32_t *phase_acc, int32_t phase_rate, int16_t scale, int32_t phase)
	Generate an integer tone sample, with modulation.
complexi_t	dds_lookup_complexi (uint32_t phase)
	Lookup the complex integer value of a specified phase.
complexi_t	dds_complexi (uint32_t *phase_acc, int32_t phase_rate)
	Generate a complex integer tone sample.
complexi_t	dds_complexi_mod (uint32_t *phase_acc, int32_t phase_rate, int16_t scale, int32_t phase)
	Generate a complex integer tone sample, with modulation.
complexi16_t	dds_lookup_complexi16 (uint32_t phase)
	Generate a complex 16 bit integer tone sample.
complexi16_t	dds_complexi16 (uint32_t *phase_acc, int32_t phase_rate)
	Generate a complex 16 bit integer tone sample.
complexi16_t	dds_complexi16_mod (uint32_t *phase_acc, int32_t phase_rate, int16_t scale, int32_t phase)
	Generate a complex 16bit integer tone sample, with modulation.
complexi32_t	dds_lookup_complexi32 (uint32_t phase)
	Generate a complex 32 bit integer tone sample.
complexi32_t	dds_complexi32 (uint32_t *phase_acc, int32_t phase_rate)
	Generate a complex 32 bit integer tone sample.
complexi32_t	dds_complexi32_mod (uint32_t *phase_acc, int32_t phase_rate, int16_t scale, int32_t phase)
	Generate a complex 32 bit integer tone sample, with modulation.

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Detailed Description

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Function Documentation

int16_t dds	(	uint32_t *	phase_acc,
		int32_t	phase_rate
	)

Generate an integer tone sample.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.

Returns:

The signal amplitude, between -32767 and 32767.

References dds_lookup().

void dds_advance	(	uint32_t *	phase_acc,
		int32_t	phase_rate
	)

Advance the phase, without returning any new signal sample.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.

Referenced by v17_rx(), v27ter_rx(), and v29_rx().

complexi_t dds_complexi	(	uint32_t *	phase_acc,
		int32_t	phase_rate
	)

Generate a complex integer tone sample.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.

Returns:

The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

Referenced by fsk_rx(), v17_tx(), v27ter_tx(), and v32bis_tx().

complexi16_t dds_complexi16	(	uint32_t *	phase_acc,
		int32_t	phase_rate
	)

Generate a complex 16 bit integer tone sample.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.

Returns:

The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

complexi16_t dds_complexi16_mod	(	uint32_t *	phase_acc,
		int32_t	phase_rate,
		int16_t	scale,
		int32_t	phase
	)

Generate a complex 16bit integer tone sample, with modulation.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.
	scale	The scaling factor.
	phase	The phase offset.

Returns:

The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

complexi32_t dds_complexi32	(	uint32_t *	phase_acc,
		int32_t	phase_rate
	)

Generate a complex 32 bit integer tone sample.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.

Returns:

The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

complexi32_t dds_complexi32_mod	(	uint32_t *	phase_acc,
		int32_t	phase_rate,
		int16_t	scale,
		int32_t	phase
	)

Generate a complex 32 bit integer tone sample, with modulation.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.
	scale	The scaling factor.
	phase	The phase offset.

Returns:

The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

complexi_t dds_complexi_mod	(	uint32_t *	phase_acc,
		int32_t	phase_rate,
		int16_t	scale,
		int32_t	phase
	)

Generate a complex integer tone sample, with modulation.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.
	scale	The scaling factor.
	phase	The phase offset.

Returns:

The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

float dds_frequency

(

int32_t

phase_rate

)

Find the frequency, in Hz, equivalent to a phase rate.

Parameters:

phase_rate

The phase rate.

Returns:

The equivalent frequency, in Hz.

Referenced by v32bis_rx_carrier_frequency().

int16_t dds_lookup

(

uint32_t

phase

)

Lookup the integer value of a specified phase.

Find the amplitude for a particular phase.

Parameters:

phase

The phase accumulator value to be looked up.

Returns:

The signal amplitude, between -32767 and 32767.

Referenced by dds(), dds_complexi(), dds_complexi16(), dds_complexi16_mod(), dds_complexi32(), dds_complexi32_mod(), dds_complexi_mod(), dds_lookup_complexi(), dds_lookup_complexi16(), dds_lookup_complexi32(), dds_mod(), and dds_offset().

complexi_t dds_lookup_complexi

(

uint32_t

phase

)

Lookup the complex integer value of a specified phase.

Parameters:

phase

The phase accumulator value to be looked up.

Returns:

The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

complexi16_t dds_lookup_complexi16

(

uint32_t

phase

)

Generate a complex 16 bit integer tone sample.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.

Returns:

The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

Referenced by v27ter_rx(), and v29_rx().

complexi32_t dds_lookup_complexi32

(

uint32_t

phase

)

Generate a complex 32 bit integer tone sample.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.

Returns:

The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

int16_t dds_mod	(	uint32_t *	phase_acc,
		int32_t	phase_rate,
		int16_t	scale,
		int32_t	phase
	)

Generate an integer tone sample, with modulation.

Parameters:

	phase_acc	A pointer to a phase accumulator value.
	phase_rate	The phase increment to be applied.
	scale	The scaling factor.
	phase	The phase offset.

Returns:

The signal amplitude, between -32767 and 32767.

References dds_lookup().

Referenced by fsk_tx(), modem_connect_tones_tx(), and sig_tone_tx().

int16_t dds_offset	(	uint32_t	phase_acc,
		int32_t	phase_offset
	)

Find the amplitude for a particular phase offset from an accumulated phase.

Parameters:

	phase_acc	The accumulated phase.
	phase_offset	The phase offset.

Returns:

The signal amplitude.

References dds_lookup().

int32_t dds_phase_rate

(

float

frequency

)

Find the phase rate value to achieve a particular frequency.

Parameters:

frequency

The desired frequency, in Hz.

Returns:

The phase rate which while achieve the desired frequency.

Referenced by fsk_rx_init(), fsk_tx_init(), make_tone_gen_descriptor(), modem_connect_tones_tx_init(), and sig_tone_tx_init().

int dds_scaling_dbm0

(

float

level

)

Find the scaling factor needed to achieve a specified level in dBm0.

Parameters:

level

The desired signal level, in dBm0.

Returns:

The scaling factor.

Referenced by fsk_tx_init(), fsk_tx_power(), make_tone_gen_descriptor(), modem_connect_tones_tx_init(), and sig_tone_tx_init().

int dds_scaling_dbov

(

float

level

)

Find the scaling factor needed to achieve a specified level in dBmov.

Parameters:

level

The desired signal level, in dBmov.

Returns:

The scaling factor.