spandsp: v22bis_rx.c File Reference

spandsp 3.0.0

#include <inttypes.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "spandsp/stdbool.h"
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/logging.h"
#include "spandsp/fast_convert.h"
#include "spandsp/math_fixed.h"
#include "spandsp/saturated.h"
#include "spandsp/complex.h"
#include "spandsp/vector_float.h"
#include "spandsp/complex_vector_float.h"
#include "spandsp/vector_int.h"
#include "spandsp/complex_vector_int.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/v22bis.h"
#include "spandsp/private/logging.h"
#include "spandsp/private/power_meter.h"
#include "spandsp/private/v22bis.h"
#include "v22bis_rx_1200_rrc.h"
#include "v22bis_rx_2400_rrc.h"

Macros
#define	FP_SCALE(x)
#define	ms_to_symbols(t)
#define	LOW_CARRIER_FREQUENCY 1200.0f
#define	HIGH_CARRIER_FREQUENCY 2400.0f
#define	EQUALIZER_DELTA 0.25f
#define	PULSESHAPER_COEFF_SETS 12

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)
void	v22bis_rx_set_signal_cutoff (v22bis_state_t *s, float cutoff)
void	v22bis_report_status_change (v22bis_state_t *s, int status)
int	v22bis_rx_equalizer_state (v22bis_state_t s, complexf_t *coeffs)
	Get a snapshot of the current equalizer coefficients.
void	v22bis_equalizer_coefficient_reset (v22bis_state_t *s)
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_fillin (v22bis_state_t *s, int len)
	Fake processing of a missing block of received V.22bis modem audio samples.
int	v22bis_rx_restart (v22bis_state_t *s)
	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)

Macro Definition Documentation

◆ EQUALIZER_DELTA

#define EQUALIZER_DELTA 0.25f

The adaption rate coefficient for the equalizer

◆ FP_SCALE

#define FP_SCALE ( x )

Value:

(x)

◆ ms_to_symbols

#define ms_to_symbols ( t )

Value:

(((t)*600)/1000)

◆ PULSESHAPER_COEFF_SETS

#define PULSESHAPER_COEFF_SETS 12

The number of phase shifted coefficient set for the pulse shaping/bandpass filter

Referenced by v22bis_rx(), and v22bis_rx_symbol_timing_correction().

Function Documentation

◆ v22bis_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_s::bit_rate, v22bis_state_s::calling_party, dds_advance(), dds_advancef(), dds_lookup_complexf(), dds_lookup_complexi16(), complexi16_t::im, power_meter_update(), PULSESHAPER_COEFF_SETS, complexi16_t::re, SIG_STATUS_CARRIER_DOWN, SIG_STATUS_CARRIER_UP, v22bis_restart(), and v22bis_rx().

Referenced by v22bis_rx().

◆ v22bis_rx_carrier_frequency()

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 dds_frequencyf(), and v22bis_rx_carrier_frequency().

Referenced by v22bis_rx_carrier_frequency().

◆ v22bis_rx_equalizer_state()

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.

References v22bis_rx_equalizer_state().

Referenced by v22bis_rx_equalizer_state().

◆ v22bis_rx_fillin()

int v22bis_rx_fillin	(	v22bis_state_t *	s,
		int	len )

Fake processing of a missing block of received V.22bis modem audio samples.

Fake processing of a missing block of received V.22bis modem audio samples. (e.g due to packet loss).

Parameters

s	The modem context.
len	The number of samples to fake.

Returns: The number of samples unprocessed.

References dds_advance(), dds_advancef(), v22bis_state_s::logging, span_log(), and v22bis_rx_fillin().

Referenced by v22bis_rx_fillin().

◆ v22bis_rx_restart()

int v22bis_rx_restart ( v22bis_state_t * s )

Reinitialise an existing V.22bis modem receive context.

Reinitialise an existing V.22bis modem receive context.

Parameters

s	The modem context.

Returns: 0 for OK, -1 for bad parameter

References v22bis_state_s::calling_party, power_meter_init(), and v22bis_rx_set_signal_cutoff().

◆ v22bis_rx_set_qam_report_handler()

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.

References v22bis_rx_set_qam_report_handler().

Referenced by v22bis_rx_set_qam_report_handler().

◆ v22bis_rx_set_signal_cutoff()

void v22bis_rx_set_signal_cutoff	(	v22bis_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.

References power_meter_level_dbm0(), and v22bis_rx_set_signal_cutoff().

Referenced by v22bis_rx_restart(), and v22bis_rx_set_signal_cutoff().

◆ v22bis_rx_signal_power()

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(), and v22bis_rx_signal_power().

Referenced by v22bis_rx_signal_power().

◆ v22bis_rx_symbol_timing_correction()

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.

References PULSESHAPER_COEFF_SETS, and v22bis_rx_symbol_timing_correction().

Referenced by v22bis_rx_symbol_timing_correction().

src
v22bis_rx.c
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