v22bis_rx.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/vector_float.h"
#include "spandsp/async.h"
#include "spandsp/power_meter.h"
#include "spandsp/arctan2.h"
#include "spandsp/complex.h"
#include "spandsp/dds.h"
#include "spandsp/complex_filters.h"
#include "spandsp/v29rx.h"
#include "spandsp/v22bis.h"

Defines
#define	ms_to_symbols(t)   (((t)*600)/1000)
#define	EQUALIZER_DELTA   0.25f
#define	PULSESHAPER_GAIN   39.98830768f
#define	PULSESHAPER_COEFF_SETS   12
Enumerations
enum	{   V22BIS_TRAINING_STAGE_NORMAL_OPERATION, V22BIS_TRAINING_STAGE_SYMBOL_ACQUISITION, V22BIS_TRAINING_STAGE_LOG_PHASE, V22BIS_TRAINING_STAGE_UNSCRAMBLED_ONES,   V22BIS_TRAINING_STAGE_UNSCRAMBLED_0011, V22BIS_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200, V22BIS_TRAINING_STAGE_SCRAMBLED_ONES_AT_2400, V22BIS_TRAINING_STAGE_WAIT_FOR_START_1,   V22BIS_TRAINING_STAGE_WAIT_FOR_START_2, V22BIS_TRAINING_STAGE_PARKED }
Functions
float	v22bis_rx_carrier_frequency (v22bis_state_t *s)
float	v22bis_rx_symbol_timing_correction (v22bis_state_t *s)
float	v22bis_rx_signal_power (v22bis_state_t *s)
int	v22bis_rx_equalizer_state (v22bis_state_t *s, complexf_t **coeffs)
	Get a snapshot of the current equalizer coefficients.
int	v22bis_rx (v22bis_state_t *s, const int16_t amp[], int len)
	Process a block of received V.22bis modem audio samples.
int	v22bis_rx_restart (v22bis_state_t *s, int bit_rate)
	Reinitialise an existing V.22bis modem receive context.
void	v22bis_rx_set_qam_report_handler (v22bis_state_t *s, qam_report_handler_t *handler, void *user_data)

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Detailed Description

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Function Documentation

int v22bis_rx	(	v22bis_state_t *	s,
		const int16_t	amp[],
		int	len
	)

Process a block of received V.22bis modem audio samples.

Process a block of received V.22bis modem audio samples.

Parameters:

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

Returns:

The number of samples unprocessed.

float v22bis_rx_carrier_frequency

(

v22bis_state_t *

s

)

Get the current received carrier frequency.

Parameters:

s

The modem context.

Returns:

The frequency, in Hertz.

int v22bis_rx_equalizer_state	(	v22bis_state_t *	s,
		complexf_t **	coeffs
	)

Get a snapshot of the current equalizer coefficients.

Get a snapshot of the current equalizer coefficients.

Parameters:

coeffs

The vector of complex coefficients.

Returns:

The number of coefficients in the vector.

int v22bis_rx_restart	(	v22bis_state_t *	s,
		int	bit_rate
	)

Reinitialise an existing V.22bis modem receive context.

Reinitialise an existing V.22bis modem receive context.

Parameters:

	s	The modem context.
	rate	The bit rate of the modem. Valid values are 1200 and 2400.

Returns:

0 for OK, -1 for bad parameter

void v22bis_rx_set_qam_report_handler	(	v22bis_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.

float v22bis_rx_signal_power

(

v22bis_state_t *

s

)

Get a current received signal power.

Parameters:

s

The modem context.

Returns:

The signal power, in dBm0.

float v22bis_rx_symbol_timing_correction

(

v22bis_state_t *

s

)

Get the current symbol timing correction since startup.

Parameters:

s

The modem context.

Returns:

The correction.

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