v17rx.h File Reference

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Classes

struct v17_rx_state_t

Defines

#define _V17RX_H_

#define V17_EQUALIZER_PRE_LEN   8

#define V17_EQUALIZER_POST_LEN   8

#define V17_RX_FILTER_STEPS   27

#define V17_TRELLIS_STORAGE_DEPTH   16

#define V17_TRELLIS_LOOKBACK_DEPTH   16

Functions

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

Initialise a V.17 modem receive context.

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

Reinitialise an existing V.17 modem receive context.

int v17_rx_free (v17_rx_state_t *s)

Free a V.17 modem receive context.

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.

void v17_rx_set_modem_status_handler (v17_rx_state_t *s, modem_rx_status_func_t handler, void *user_data)

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

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

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

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

Get a snapshot of the current equalizer coefficients.

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)

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

Detailed Description

Function Documentation

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

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.

Returns:: The number of samples unprocessed.

References v17_rx_state_t::agc_scaling, v17_rx_state_t::agc_scaling_save, v17_rx_state_t::bit_rate, v17_rx_state_t::carrier_drop_pending, v17_rx_state_t::carrier_phase, v17_rx_state_t::carrier_phase_rate, dds_advance(), dds_advancef(), dds_lookup_complexf(), v17_rx_state_t::eq_put_step, v17_rx_state_t::high_sample, complexf_t::im, v17_rx_state_t::last_sample, v17_rx_state_t::low_samples, v17_rx_state_t::power, power_meter_init(), power_meter_update(), complexf_t::re, v17_rx_state_t::rrc_filter, v17_rx_state_t::rrc_filter_step, v17_rx_state_t::short_train, SIG_STATUS_CARRIER_DOWN, SIG_STATUS_CARRIER_UP, v17_rx_state_t::signal_present, v17_rx_state_t::symbol_sync_high, v17_rx_state_t::symbol_sync_low, v17_rx_state_t::training_stage, v17_rx_restart(), vec_circular_dot_prodf(), and vec_circular_dot_prodi16().

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.

References v17_rx_state_t::carrier_phase_rate, and dds_frequencyf().

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

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.

References v17_rx_state_t::eq_coeff.

int v17_rx_free ( v17_rx_state_t * s )

Free a V.17 modem receive context.

Parameters:

s

The modem context.

Returns:: 0 for OK

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

Initialise a V.17 modem receive context.

Parameters:

	s	The modem context.
	bit_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.

References v17_rx_state_t::agc_scaling, v17_rx_state_t::agc_scaling_save, v17_rx_state_t::carrier_phase_rate_save, dds_phase_ratef(), v17_rx_state_t::logging, v17_rx_state_t::put_bit, v17_rx_state_t::put_bit_user_data, v17_rx_state_t::short_train, v17_rx_restart(), and v17_rx_signal_cutoff().

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

Reinitialise an existing V.17 modem receive context.

Parameters:

	s	The modem context.
	bit_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

References v17_rx_state_t::agc_scaling, v17_rx_state_t::agc_scaling_save, v17_rx_state_t::angles, v17_rx_state_t::baud_half, v17_rx_state_t::baud_phase, v17_rx_state_t::bit_rate, v17_rx_state_t::bits_per_symbol, v17_rx_state_t::carrier_drop_pending, v17_rx_state_t::carrier_phase, v17_rx_state_t::carrier_phase_rate, v17_rx_state_t::carrier_phase_rate_save, v17_rx_state_t::carrier_track_i, v17_rx_state_t::carrier_track_p, v17_rx_state_t::constellation, dds_frequencyf(), dds_phase_ratef(), v17_rx_state_t::diff, v17_rx_state_t::distances, v17_rx_state_t::full_path_to_past_state_locations, v17_rx_state_t::high_sample, v17_rx_state_t::last_sample, v17_rx_state_t::logging, v17_rx_state_t::low_samples, v17_rx_state_t::past_state_locations, v17_rx_state_t::power, power_meter_init(), v17_rx_state_t::rrc_filter, v17_rx_state_t::rrc_filter_step, v17_rx_state_t::scramble_reg, v17_rx_state_t::short_train, v17_rx_state_t::signal_present, v17_rx_state_t::space_map, span_log(), v17_rx_state_t::start_angles, v17_rx_state_t::symbol_sync_dc_filter, v17_rx_state_t::symbol_sync_high, v17_rx_state_t::symbol_sync_low, v17_rx_state_t::total_baud_timing_correction, v17_rx_state_t::training_count, v17_rx_state_t::training_error, v17_rx_state_t::training_stage, and v17_rx_state_t::trellis_ptr.

Referenced by v17_rx(), and v17_rx_init().

void v17_rx_set_modem_status_handler	(	v17_rx_state_t *	s,
		modem_rx_status_func_t	handler,
		void *	user_data
	)

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

Parameters:

	s	The modem context.
	handler	The callback routine used to report modem status changes.
	user_data	An opaque pointer.

References v17_rx_state_t::status_handler, and v17_rx_state_t::status_user_data.

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.

Parameters:

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

References v17_rx_state_t::put_bit, and v17_rx_state_t::put_bit_user_data.

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.

References v17_rx_state_t::qam_report, and v17_rx_state_t::qam_user_data.

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.

References v17_rx_state_t::carrier_off_power, v17_rx_state_t::carrier_on_power, and power_meter_level_dbm0().

Referenced by v17_rx_init().

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.

References v17_rx_state_t::power, and power_meter_current_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.

References v17_rx_state_t::total_baud_timing_correction.


Classes
struct	v17_rx_state_t
Defines
#define	_V17RX_H_
#define	V17_EQUALIZER_PRE_LEN 8
#define	V17_EQUALIZER_POST_LEN 8
#define	V17_RX_FILTER_STEPS 27
#define	V17_TRELLIS_STORAGE_DEPTH 16
#define	V17_TRELLIS_LOOKBACK_DEPTH 16
Functions
v17_rx_state_t *	v17_rx_init (v17_rx_state_t s, int bit_rate, put_bit_func_t put_bit, void user_data)
	Initialise a V.17 modem receive context.
int	v17_rx_restart (v17_rx_state_t *s, int bit_rate, int short_train)
	Reinitialise an existing V.17 modem receive context.
int	v17_rx_free (v17_rx_state_t *s)
	Free a V.17 modem receive context.
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.
void	v17_rx_set_modem_status_handler (v17_rx_state_t s, modem_rx_status_func_t handler, void user_data)
	Change the modem status report function associated with a V.17 modem receive context.
int	v17_rx (v17_rx_state_t *s, const int16_t amp[], int len)
	Process a block of received V.17 modem audio samples.
int	v17_rx_equalizer_state (v17_rx_state_t s, complexf_t *coeffs)
	Get a snapshot of the current equalizer coefficients.
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)
void	v17_rx_set_qam_report_handler (v17_rx_state_t s, qam_report_handler_t handler, void user_data)