v17rx.c File Reference

#include <inttypes.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "spandsp/telephony.h"
#include "spandsp/logging.h"
#include "spandsp/complex.h"
#include "spandsp/vector_float.h"
#include "spandsp/complex_vector_float.h"
#include "spandsp/async.h"
#include "spandsp/power_meter.h"
#include "spandsp/arctan2.h"
#include "spandsp/dds.h"
#include "spandsp/complex_filters.h"
#include "spandsp/v29rx.h"
#include "spandsp/v17tx.h"
#include "spandsp/v17rx.h"
#include "v17rx_constellation_maps.h"
#include "v17rx_floating_rrc.h"

Defines
#define	CARRIER_NOMINAL_FREQ   1800.0f
#define	BAUD_RATE   2400
#define	EQUALIZER_DELTA   0.21f
#define	EQUALIZER_SLOW_ADAPT_RATIO   0.1f
#define	V17_TRAINING_SEG_1_LEN   256
#define	V17_TRAINING_SEG_2_LEN   2976
#define	V17_TRAINING_SHORT_SEG_2_LEN   38
#define	V17_TRAINING_SEG_3_LEN   64
#define	V17_TRAINING_SEG_4A_LEN   15
#define	V17_TRAINING_SEG_4_LEN   48
#define	V17_BRIDGE_WORD   0x8880
#define	SYNC_LOW_BAND_EDGE_COEFF_0   1.764193f
#define	SYNC_LOW_BAND_EDGE_COEFF_1   -0.980100f
#define	SYNC_HIGH_BAND_EDGE_COEFF_0   -1.400072f
#define	SYNC_HIGH_BAND_EDGE_COEFF_1   -0.980100f
#define	SYNC_CROSS_CORR_COEFF_A   -0.932131f
#define	SYNC_CROSS_CORR_COEFF_B   0.700036f
#define	SYNC_CROSS_CORR_COEFF_C   -0.449451f
Enumerations
enum	{   TRAINING_STAGE_NORMAL_OPERATION = 0, TRAINING_STAGE_SYMBOL_ACQUISITION, TRAINING_STAGE_LOG_PHASE, TRAINING_STAGE_SHORT_WAIT_FOR_CDBA,   TRAINING_STAGE_WAIT_FOR_CDBA, TRAINING_STAGE_TRAIN_ON_CDBA, TRAINING_STAGE_SHORT_TRAIN_ON_CDBA_AND_TEST, TRAINING_STAGE_TRAIN_ON_CDBA_AND_TEST,   TRAINING_STAGE_BRIDGE, TRAINING_STAGE_TCM_WINDUP, TRAINING_STAGE_TEST_ONES, TRAINING_STAGE_PARKED }
Functions
float	v17_rx_carrier_frequency (v17_rx_state_t *s)
float	v17_rx_symbol_timing_correction (v17_rx_state_t *s)
float	v17_rx_signal_power (v17_rx_state_t *s)
void	v17_rx_signal_cutoff (v17_rx_state_t *s, float cutoff)
int	v17_rx_equalizer_state (v17_rx_state_t *s, complexf_t **coeffs)
	Get a snapshot of the current equalizer coefficients.
void	v17_rx (v17_rx_state_t *s, const int16_t amp[], int len)
	Process a block of received V.17 modem audio samples.
void	v17_rx_set_put_bit (v17_rx_state_t *s, put_bit_func_t put_bit, void *user_data)
	Change the put_bit function associated with a V.17 modem receive context.
int	v17_rx_restart (v17_rx_state_t *s, int rate, int short_train)
	Reinitialise an existing V.17 modem receive context.
v17_rx_state_t *	v17_rx_init (v17_rx_state_t *s, int rate, put_bit_func_t put_bit, void *user_data)
	Initialise a V.17 modem receive context.
int	v17_rx_release (v17_rx_state_t *s)
	Release a V.17 modem receive context.
void	v17_rx_set_qam_report_handler (v17_rx_state_t *s, qam_report_handler_t *handler, void *user_data)

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Detailed Description

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Function Documentation

void v17_rx	(	v17_rx_state_t *	s,
		const int16_t	amp[],
		int	len
	)

Process a block of received V.17 modem audio samples.

Process a block of received V.17 modem audio samples.

Parameters:

	s	The modem context.
	amp	The audio sample buffer.
	len	The number of samples in the buffer.

float v17_rx_carrier_frequency

(

v17_rx_state_t *

s

)

Get the current received carrier frequency.

Parameters:

s

The modem context.

Returns:

The frequency, in Hertz.

int v17_rx_equalizer_state	(	v17_rx_state_t *	s,
		complexf_t **	coeffs
	)

Get a snapshot of the current equalizer coefficients.

Get a snapshot of the current equalizer coefficients.

Parameters:

	s	The modem context.
	coeffs	The vector of complex coefficients.

Returns:

The number of coefficients in the vector.

v17_rx_state_t* v17_rx_init	(	v17_rx_state_t *	s,
		int	rate,
		put_bit_func_t	put_bit,
		void *	user_data
	)

Initialise a V.17 modem receive context.

Initialise a V.17 modem receive context.

Parameters:

	s	The modem context.
	rate	The bit rate of the modem. Valid values are 7200, 9600, 12000 and 14400.
	put_bit	The callback routine used to put the received data.
	user_data	An opaque pointer passed to the put_bit routine.

Returns:

A pointer to the modem context, or NULL if there was a problem.

int v17_rx_release

(

v17_rx_state_t *

s

)

Release a V.17 modem receive context.

Release a V.17 modem receive context.

Parameters:

s

The modem context.

Returns:

0 for OK

int v17_rx_restart	(	v17_rx_state_t *	s,
		int	rate,
		int	short_train
	)

Reinitialise an existing V.17 modem receive context.

Reinitialise an existing V.17 modem receive context.

Parameters:

	s	The modem context.
	rate	The bit rate of the modem. Valid values are 7200, 9600, 12000 and 14400.
	short_train	TRUE if a short training sequence is expected.

Returns:

0 for OK, -1 for bad parameter

void v17_rx_set_put_bit	(	v17_rx_state_t *	s,
		put_bit_func_t	put_bit,
		void *	user_data
	)

Change the put_bit function associated with a V.17 modem receive context.

Change the put_bit function associated with a V.17 modem receive context.

Parameters:

	s	The modem context.
	put_bit	The callback routine used to handle received bits.
	user_data	An opaque pointer.

void v17_rx_set_qam_report_handler	(	v17_rx_state_t *	s,
		qam_report_handler_t *	handler,
		void *	user_data
	)

Set a handler routine to process QAM status reports

Parameters:

	s	The modem context.
	handler	The handler routine.
	user_data	An opaque pointer passed to the handler routine.

void v17_rx_signal_cutoff	(	v17_rx_state_t *	s,
		float	cutoff
	)

Set the power level at which the carrier detection will cut in

Parameters:

	s	The modem context.
	cutoff	The signal cutoff power, in dBm0.

float v17_rx_signal_power

(

v17_rx_state_t *

s

)

Get a current received signal power.

Parameters:

s

The modem context.

Returns:

The signal power, in dBm0.

float v17_rx_symbol_timing_correction

(

v17_rx_state_t *

s

)

Get the current symbol timing correction since startup.

Parameters:

s

The modem context.

Returns:

The correction.

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