v22bis_rx.c File Reference

#include <inttypes.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "floating_fudge.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"
#include "v22bis_rx_1200_floating_rrc.h"
#include "v22bis_rx_2400_floating_rrc.h"

Defines
#define	ms_to_symbols(t)   (((t)*600)/1000)
#define	EQUALIZER_DELTA   0.25f
#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_symbol_timing_correction (v22bis_state_t *s)
float	v22bis_rx_signal_power (v22bis_state_t *s)
int	v22bis_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_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_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.

References v22bis_state_t::eq_coeff, and v22bis_state_t::rx.

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.

References v22bis_state_t::agc_scaling, v22bis_state_t::bit_rate, v22bis_state_t::caller, v22bis_state_t::carrier_phase, v22bis_state_t::carrier_phase_rate, dds_complexf(), v22bis_state_t::eq_put_step, complexf_t::im, power_meter_update(), v22bis_state_t::put_bit, complexf_t::re, v22bis_state_t::rrc_filter, v22bis_state_t::rrc_filter_step, v22bis_state_t::rx, v22bis_state_t::rx_power, SIG_STATUS_CARRIER_DOWN, SIG_STATUS_CARRIER_UP, v22bis_state_t::signal_present, v22bis_state_t::training, v22bis_state_t::user_data, and v22bis_rx_restart().

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.

References v22bis_state_t::carrier_phase_rate, dds_frequencyf(), and v22bis_state_t::rx.

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

Returns:

0 for OK, -1 for bad parameter

References v22bis_state_t::agc_scaling, v22bis_state_t::baud_phase, v22bis_state_t::bit_rate, v22bis_state_t::caller, v22bis_state_t::carrier_off_power, v22bis_state_t::carrier_on_power, v22bis_state_t::carrier_phase, v22bis_state_t::carrier_phase_rate, v22bis_state_t::carrier_track_i, v22bis_state_t::carrier_track_p, v22bis_state_t::constellation_state, dds_phase_ratef(), v22bis_state_t::detected_unscrambled_ones, v22bis_state_t::detected_unscrambled_zeros, v22bis_state_t::gardner_integrate, v22bis_state_t::gardner_step, power_meter_init(), power_meter_level_dbm0(), v22bis_state_t::rrc_filter, v22bis_state_t::rrc_filter_step, v22bis_state_t::rx, v22bis_state_t::rx_power, v22bis_state_t::scramble_reg, v22bis_state_t::scrambler_pattern_count, v22bis_state_t::signal_present, v22bis_state_t::sixteen_way_decisions, v22bis_state_t::training, and v22bis_state_t::training_count.

Referenced by v22bis_restart(), and v22bis_rx().

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.

References power_meter_current_dbm0(), v22bis_state_t::rx, and v22bis_state_t::rx_power.

void v22bis_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.

References v22bis_state_t::qam_report, v22bis_state_t::qam_user_data, and v22bis_state_t::rx.

float v22bis_symbol_timing_correction

(

v22bis_state_t *

s

)

Get the current symbol timing correction since startup.

Parameters:

s

The modem context.

Returns:

The correction.

References v22bis_state_t::rx, and v22bis_state_t::total_baud_timing_correction.