private/v22bis.h
/*
* SpanDSP - a series of DSP components for telephony
*
* private/v22bis.h - ITU V.22bis modem
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2004 Steve Underwood
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#if !defined(_SPANDSP_PRIVATE_V22BIS_H_)
#define _SPANDSP_PRIVATE_V22BIS_H_
/*! The number of steps to the left and to the right of the target position in the equalizer buffer. */
#define V22BIS_EQUALIZER_LEN 7
/*! One less than a power of 2 >= (2*V22BIS_EQUALIZER_LEN + 1) */
#define V22BIS_EQUALIZER_MASK 15
/*! The number of taps in the transmit pulse shaping filter */
#define V22BIS_TX_FILTER_STEPS 9
/*! The number of taps in the receive pulse shaping/bandpass filter */
#define V22BIS_RX_FILTER_STEPS 27
/*! Segments of the training sequence on the receive side */
enum
{
V22BIS_RX_TRAINING_STAGE_NORMAL_OPERATION,
V22BIS_RX_TRAINING_STAGE_SYMBOL_ACQUISITION,
V22BIS_RX_TRAINING_STAGE_LOG_PHASE,
V22BIS_RX_TRAINING_STAGE_UNSCRAMBLED_ONES,
V22BIS_RX_TRAINING_STAGE_UNSCRAMBLED_ONES_SUSTAINING,
V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200,
V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200_SUSTAINING,
V22BIS_RX_TRAINING_STAGE_WAIT_FOR_SCRAMBLED_ONES_AT_2400,
V22BIS_RX_TRAINING_STAGE_PARKED
};
/*! Segments of the training sequence on the transmit side */
enum
{
V22BIS_TX_TRAINING_STAGE_NORMAL_OPERATION = 0,
V22BIS_TX_TRAINING_STAGE_INITIAL_TIMED_SILENCE,
V22BIS_TX_TRAINING_STAGE_INITIAL_SILENCE,
V22BIS_TX_TRAINING_STAGE_U11,
V22BIS_TX_TRAINING_STAGE_U0011,
V22BIS_TX_TRAINING_STAGE_S11,
V22BIS_TX_TRAINING_STAGE_TIMED_S11,
V22BIS_TX_TRAINING_STAGE_S1111,
V22BIS_TX_TRAINING_STAGE_PARKED
};
/*!
V.22bis modem descriptor. This defines the working state for a single instance
of a V.22bis modem.
*/
struct v22bis_state_s
{
/*! \brief The maximum permitted bit rate of the modem. Valid values are 1200 and 2400. */
int bit_rate;
/*! \brief TRUE is this is the calling side modem. */
int calling_party;
/*! \brief The callback function used to get the next bit to be transmitted. */
get_bit_func_t get_bit;
/*! \brief A user specified opaque pointer passed to the get_bit callback routine. */
void *get_bit_user_data;
/*! \brief The callback function used to put each bit received. */
put_bit_func_t put_bit;
/*! \brief A user specified opaque pointer passed to the put_bit callback routine. */
void *put_bit_user_data;
/*! \brief The callback function used to report modem status changes. */
modem_status_func_t status_handler;
/*! \brief A user specified opaque pointer passed to the status function. */
void *status_user_data;
int negotiated_bit_rate;
/* Receive section */
struct
{
/*! \brief Current offset into the RRC pulse shaping filter buffer. */
int rrc_filter_step;
/*! \brief The register for the data scrambler. */
uint32_t scramble_reg;
/*! \brief A counter for the number of consecutive bits of repeating pattern through
the scrambler. */
int scrambler_pattern_count;
/*! \brief 0 if receiving user data. A training stage value during training */
int training;
/*! \brief A count of how far through the current training step we are. */
int training_count;
/*! \brief >0 if a signal above the minimum is present. It may or may not be a V.22bis signal. */
int signal_present;
/*! \brief The current phase of the carrier (i.e. the DDS parameter). */
uint32_t carrier_phase;
/*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */
int32_t carrier_phase_rate;
/*! \brief A callback function which may be enabled to report every symbol's
constellation position. */
qam_report_handler_t qam_report;
/*! \brief A user specified opaque pointer passed to the qam_report callback
routine. */
void *qam_user_data;
/*! \brief A power meter, to measure the HPF'ed signal power in the channel. */
power_meter_t rx_power;
/*! \brief The power meter level at which carrier on is declared. */
int32_t carrier_on_power;
/*! \brief The power meter level at which carrier off is declared. */
int32_t carrier_off_power;
int constellation_state;
#if defined(SPANDSP_USE_FIXED_POINTx)
/*! \brief The scaling factor accessed by the AGC algorithm. */
float agc_scaling;
/*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
int16_t rrc_filter[V22BIS_RX_FILTER_STEPS];
/*! \brief The current delta factor for updating the equalizer coefficients. */
float eq_delta;
/*! \brief The adaptive equalizer coefficients. */
complexi_t eq_coeff[2*V22BIS_EQUALIZER_LEN + 1];
/*! \brief The equalizer signal buffer. */
complexi_t eq_buf[V22BIS_EQUALIZER_MASK + 1];
/*! \brief A measure of how much mismatch there is between the real constellation,
and the decoded symbol positions. */
float training_error;
/*! \brief The proportional part of the carrier tracking filter. */
float carrier_track_p;
/*! \brief The integral part of the carrier tracking filter. */
float carrier_track_i;
#else
/*! \brief The scaling factor accessed by the AGC algorithm. */
float agc_scaling;
/*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
float rrc_filter[V22BIS_RX_FILTER_STEPS];
/*! \brief The current delta factor for updating the equalizer coefficients. */
float eq_delta;
/*! \brief The adaptive equalizer coefficients. */
complexf_t eq_coeff[2*V22BIS_EQUALIZER_LEN + 1];
/*! \brief The equalizer signal buffer. */
complexf_t eq_buf[V22BIS_EQUALIZER_MASK + 1];
/*! \brief A measure of how much mismatch there is between the real constellation,
and the decoded symbol positions. */
float training_error;
/*! \brief The proportional part of the carrier tracking filter. */
float carrier_track_p;
/*! \brief The integral part of the carrier tracking filter. */
float carrier_track_i;
#endif
/*! \brief Current offset into the equalizer buffer. */
int eq_step;
/*! \brief Current write offset into the equalizer buffer. */
int eq_put_step;
/*! \brief Integration variable for damping the Gardner algorithm tests. */
int gardner_integrate;
/*! \brief Current step size of Gardner algorithm integration. */
int gardner_step;
/*! \brief The total symbol timing correction since the carrier came up.
This is only for performance analysis purposes. */
int total_baud_timing_correction;
/*! \brief The current fractional phase of the baud timing. */
int baud_phase;
int sixteen_way_decisions;
int pattern_repeats;
int last_raw_bits;
} rx;
/* Transmit section */
struct
{
#if defined(SPANDSP_USE_FIXED_POINTx)
/*! \brief The guard tone level. */
float guard_level;
/*! \brief The gain factor needed to achieve the specified output power. */
float gain;
/*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
complexf_t rrc_filter[2*V22BIS_TX_FILTER_STEPS];
#else
/*! \brief The guard tone level. */
float guard_level;
/*! \brief The gain factor needed to achieve the specified output power. */
float gain;
/*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
complexf_t rrc_filter[2*V22BIS_TX_FILTER_STEPS];
#endif
/*! \brief Current offset into the RRC pulse shaping filter buffer. */
int rrc_filter_step;
/*! \brief The register for the data scrambler. */
uint32_t scramble_reg;
/*! \brief A counter for the number of consecutive bits of repeating pattern through
the scrambler. */
int scrambler_pattern_count;
/*! \brief 0 if transmitting user data. A training stage value during training */
int training;
/*! \brief A counter used to track progress through sending the training sequence. */
int training_count;
/*! \brief The current phase of the carrier (i.e. the DDS parameter). */
uint32_t carrier_phase;
/*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */
int32_t carrier_phase_rate;
/*! \brief The current phase of the guard tone (i.e. the DDS parameter). */
uint32_t guard_phase;
/*! \brief The update rate for the phase of the guard tone (i.e. the DDS increment). */
int32_t guard_phase_rate;
/*! \brief The current fractional phase of the baud timing. */
int baud_phase;
/*! \brief The code number for the current position in the constellation. */
int constellation_state;
/*! \brief An indicator to mark that we are tidying up to stop transmission. */
int shutdown;
/*! \brief The get_bit function in use at any instant. */
get_bit_func_t current_get_bit;
} tx;
/*! \brief Error and flow logging control */
logging_state_t logging;
};
#if defined(__cplusplus)
extern "C"
{
#endif
/*! Reinitialise an existing V.22bis modem receive context.
\brief Reinitialise an existing V.22bis modem receive context.
\param s The modem context.
\return 0 for OK, -1 for bad parameter */
int v22bis_rx_restart(v22bis_state_t *s);
void v22bis_report_status_change(v22bis_state_t *s, int status);
void v22bis_equalizer_coefficient_reset(v22bis_state_t *s);
#if defined(__cplusplus)
}
#endif
#endif
/*- End of file ------------------------------------------------------------*/
modem_status_func_t
void(* modem_status_func_t)(void *user_data, int status)
Definition async.h:114
put_bit_func_t
void(* put_bit_func_t)(void *user_data, int bit)
Definition async.h:105
get_bit_func_t
int(* get_bit_func_t)(void *user_data)
Definition async.h:108
logging_state_t
struct logging_state_s logging_state_t
Definition logging.h:75
complexf_t
Definition complex.h:43
complexi_t
Definition complex.h:78
power_meter_t
Definition power_meter.h:49
v22bis_state_s
Definition private/v22bis.h:73
v22bis_state_s::logging
logging_state_t logging
Error and flow logging control.
Definition private/v22bis.h:246
v22bis_state_s::baud_phase
int baud_phase
The current fractional phase of the baud timing.
Definition private/v22bis.h:188
v22bis_state_s::bit_rate
int bit_rate
The maximum permitted bit rate of the modem. Valid values are 1200 and 2400.
Definition private/v22bis.h:75
v22bis_state_s::current_get_bit
get_bit_func_t current_get_bit
The get_bit function in use at any instant.
Definition private/v22bis.h:242
v22bis_state_s::eq_put_step
int eq_put_step
Current write offset into the equalizer buffer.
Definition private/v22bis.h:178
v22bis_state_s::rrc_filter
float rrc_filter[27]
The root raised cosine (RRC) pulse shaping filter buffer.
Definition private/v22bis.h:158
v22bis_state_s::qam_report
qam_report_handler_t qam_report
A callback function which may be enabled to report every symbol's constellation position.
Definition private/v22bis.h:120
v22bis_state_s::constellation_state
int constellation_state
The code number for the current position in the constellation.
Definition private/v22bis.h:132
v22bis_state_s::training_count
int training_count
A count of how far through the current training step we are.
Definition private/v22bis.h:108
v22bis_state_s::gain
float gain
The gain factor needed to achieve the specified output power.
Definition private/v22bis.h:210
v22bis_state_s::status_user_data
void * status_user_data
A user specified opaque pointer passed to the status function.
Definition private/v22bis.h:89
v22bis_state_s::eq_coeff
complexf_t eq_coeff[2 *7+1]
The adaptive equalizer coefficients.
Definition private/v22bis.h:163
v22bis_state_s::scrambler_pattern_count
int scrambler_pattern_count
A counter for the number of consecutive bits of repeating pattern through the scrambler.
Definition private/v22bis.h:103
v22bis_state_s::total_baud_timing_correction
int total_baud_timing_correction
The total symbol timing correction since the carrier came up. This is only for performance analysis p...
Definition private/v22bis.h:186
v22bis_state_s::qam_user_data
void * qam_user_data
A user specified opaque pointer passed to the qam_report callback routine.
Definition private/v22bis.h:123
v22bis_state_s::eq_buf
complexf_t eq_buf[15+1]
The equalizer signal buffer.
Definition private/v22bis.h:165
v22bis_state_s::shutdown
int shutdown
An indicator to mark that we are tidying up to stop transmission.
Definition private/v22bis.h:240
v22bis_state_s::put_bit_user_data
void * put_bit_user_data
A user specified opaque pointer passed to the put_bit callback routine.
Definition private/v22bis.h:85
v22bis_state_s::gardner_integrate
int gardner_integrate
Integration variable for damping the Gardner algorithm tests.
Definition private/v22bis.h:181
v22bis_state_s::eq_delta
float eq_delta
The current delta factor for updating the equalizer coefficients.
Definition private/v22bis.h:161
v22bis_state_s::training
int training
0 if receiving user data. A training stage value during training
Definition private/v22bis.h:106
v22bis_state_s::guard_phase
uint32_t guard_phase
The current phase of the guard tone (i.e. the DDS parameter).
Definition private/v22bis.h:232
v22bis_state_s::carrier_on_power
int32_t carrier_on_power
The power meter level at which carrier on is declared.
Definition private/v22bis.h:128
v22bis_state_s::rx_power
power_meter_t rx_power
A power meter, to measure the HPF'ed signal power in the channel.
Definition private/v22bis.h:126
v22bis_state_s::carrier_track_p
float carrier_track_p
The proportional part of the carrier tracking filter.
Definition private/v22bis.h:171
v22bis_state_s::calling_party
int calling_party
TRUE is this is the calling side modem.
Definition private/v22bis.h:77
v22bis_state_s::agc_scaling
float agc_scaling
The scaling factor accessed by the AGC algorithm.
Definition private/v22bis.h:156
v22bis_state_s::put_bit
put_bit_func_t put_bit
The callback function used to put each bit received.
Definition private/v22bis.h:83
v22bis_state_s::carrier_phase
uint32_t carrier_phase
The current phase of the carrier (i.e. the DDS parameter).
Definition private/v22bis.h:114
v22bis_state_s::signal_present
int signal_present
>0 if a signal above the minimum is present. It may or may not be a V.22bis signal.
Definition private/v22bis.h:111
v22bis_state_s::status_handler
modem_status_func_t status_handler
The callback function used to report modem status changes.
Definition private/v22bis.h:87
v22bis_state_s::guard_level
float guard_level
The guard tone level.
Definition private/v22bis.h:208
v22bis_state_s::eq_step
int eq_step
Current offset into the equalizer buffer.
Definition private/v22bis.h:176
v22bis_state_s::gardner_step
int gardner_step
Current step size of Gardner algorithm integration.
Definition private/v22bis.h:183
v22bis_state_s::scramble_reg
uint32_t scramble_reg
The register for the data scrambler.
Definition private/v22bis.h:100
v22bis_state_s::rrc_filter_step
int rrc_filter_step
Current offset into the RRC pulse shaping filter buffer.
Definition private/v22bis.h:97
v22bis_state_s::get_bit_user_data
void * get_bit_user_data
A user specified opaque pointer passed to the get_bit callback routine.
Definition private/v22bis.h:81
v22bis_state_s::guard_phase_rate
int32_t guard_phase_rate
The update rate for the phase of the guard tone (i.e. the DDS increment).
Definition private/v22bis.h:234
v22bis_state_s::carrier_phase_rate
int32_t carrier_phase_rate
The update rate for the phase of the carrier (i.e. the DDS increment).
Definition private/v22bis.h:116
v22bis_state_s::carrier_off_power
int32_t carrier_off_power
The power meter level at which carrier off is declared.
Definition private/v22bis.h:130
v22bis_state_s::get_bit
get_bit_func_t get_bit
The callback function used to get the next bit to be transmitted.
Definition private/v22bis.h:79
v22bis_state_s::training_error
float training_error
A measure of how much mismatch there is between the real constellation, and the decoded symbol positi...
Definition private/v22bis.h:169
v22bis_state_s::carrier_track_i
float carrier_track_i
The integral part of the carrier tracking filter.
Definition private/v22bis.h:173
v22bis_state_t
struct v22bis_state_s v22bis_state_t
Definition v22bis.h:62