/* * SpanDSP - a series of DSP components for telephony * * private/v22bis.h - ITU V.22bis modem * * Written by Steve Underwood * * 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 length of the equalizer buffer */ #define V22BIS_EQUALIZER_LEN 17 /*! Samples before the target position in the equalizer buffer */ #define V22BIS_EQUALIZER_PRE_LEN 8 /*! 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 }; #if defined(SPANDSP_USE_FIXED_POINT) extern const complexi16_t v22bis_constellation[16]; #else extern const complexf_t v22bis_constellation[16]; #endif /*! 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_POINT) /*! \brief The scaling factor accessed by the AGC algorithm. */ int16_t 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. */ int16_t eq_delta; /*! \brief The adaptive equalizer coefficients. */ complexi16_t eq_coeff[V22BIS_EQUALIZER_LEN]; /*! \brief The equalizer signal buffer. */ complexi16_t eq_buf[V22BIS_EQUALIZER_LEN]; /*! \brief A measure of how much mismatch there is between the real constellation, and the decoded symbol positions. */ int32_t training_error; /*! \brief The proportional part of the carrier tracking filter. */ int32_t carrier_track_p; /*! \brief The integral part of the carrier tracking filter. */ int32_t 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[V22BIS_EQUALIZER_LEN]; /*! \brief The equalizer signal buffer. */ complexf_t eq_buf[V22BIS_EQUALIZER_LEN]; /*! \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_POINT) /*! \brief The guard tone level. */ int16_t guard_tone_gain; /*! \brief The gain factor needed to achieve the specified output power. */ int16_t gain; /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */ int16_t rrc_filter_re[V22BIS_TX_FILTER_STEPS]; int16_t rrc_filter_im[V22BIS_TX_FILTER_STEPS]; #else /*! \brief The guard tone level. */ float guard_tone_gain; /*! \brief The gain factor needed to achieve the specified output power. */ float gain; /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */ float rrc_filter_re[V22BIS_TX_FILTER_STEPS]; float rrc_filter_im[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 ------------------------------------------------------------*/