00001 /* 00002 * SpanDSP - a series of DSP components for telephony 00003 * 00004 * private/v29rx.h - ITU V.29 modem receive part 00005 * 00006 * Written by Steve Underwood <steveu@coppice.org> 00007 * 00008 * Copyright (C) 2003 Steve Underwood 00009 * 00010 * All rights reserved. 00011 * 00012 * This program is free software; you can redistribute it and/or modify 00013 * it under the terms of the GNU Lesser General Public License version 2.1, 00014 * as published by the Free Software Foundation. 00015 * 00016 * This program is distributed in the hope that it will be useful, 00017 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00018 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00019 * GNU Lesser General Public License for more details. 00020 * 00021 * You should have received a copy of the GNU Lesser General Public 00022 * License along with this program; if not, write to the Free Software 00023 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00024 * 00025 * $Id: v29rx.h,v 1.1 2008/10/13 13:14:01 steveu Exp $ 00026 */ 00027 00028 #if !defined(_SPANDSP_PRIVATE_V29RX_H_) 00029 #define _SPANDSP_PRIVATE_V29RX_H_ 00030 00031 /*! 00032 V.29 modem receive side descriptor. This defines the working state for a 00033 single instance of a V.29 modem receiver. 00034 */ 00035 struct v29_rx_state_s 00036 { 00037 /*! \brief The bit rate of the modem. Valid values are 4800, 7200 and 9600. */ 00038 int bit_rate; 00039 /*! \brief The callback function used to put each bit received. */ 00040 put_bit_func_t put_bit; 00041 /*! \brief A user specified opaque pointer passed to the put_bit routine. */ 00042 void *put_bit_user_data; 00043 00044 /*! \brief The callback function used to report modem status changes. */ 00045 modem_rx_status_func_t status_handler; 00046 /*! \brief A user specified opaque pointer passed to the status function. */ 00047 void *status_user_data; 00048 00049 /*! \brief A callback function which may be enabled to report every symbol's 00050 constellation position. */ 00051 qam_report_handler_t qam_report; 00052 /*! \brief A user specified opaque pointer passed to the qam_report callback 00053 routine. */ 00054 void *qam_user_data; 00055 00056 /*! \brief The route raised cosine (RRC) pulse shaping filter buffer. */ 00057 #if defined(SPANDSP_USE_FIXED_POINT) 00058 int16_t rrc_filter[V29_RX_FILTER_STEPS]; 00059 #else 00060 float rrc_filter[V29_RX_FILTER_STEPS]; 00061 #endif 00062 /*! \brief Current offset into the RRC pulse shaping filter buffer. */ 00063 int rrc_filter_step; 00064 00065 /*! \brief The register for the data scrambler. */ 00066 unsigned int scramble_reg; 00067 /*! \brief The register for the training scrambler. */ 00068 uint8_t training_scramble_reg; 00069 /*! \brief The current step in the table of CD constellation positions. */ 00070 int training_cd; 00071 /*! \brief TRUE if the previous trained values are to be reused. */ 00072 int old_train; 00073 /*! \brief The section of the training data we are currently in. */ 00074 int training_stage; 00075 /*! \brief A count of how far through the current training step we are. */ 00076 int training_count; 00077 /*! \brief A measure of how much mismatch there is between the real constellation, 00078 and the decoded symbol positions. */ 00079 float training_error; 00080 /*! \brief The value of the last signal sample, using the a simple HPF for signal power estimation. */ 00081 int16_t last_sample; 00082 /*! \brief >0 if a signal above the minimum is present. It may or may not be a V.29 signal. */ 00083 int signal_present; 00084 /*! \brief Whether or not a carrier drop was detected and the signal delivery is pending. */ 00085 int carrier_drop_pending; 00086 /*! \brief A count of the current consecutive samples below the carrier off threshold. */ 00087 int low_samples; 00088 /*! \brief A highest magnitude sample seen. */ 00089 int16_t high_sample; 00090 00091 /*! \brief The position of the current symbol in the constellation, used for 00092 differential decoding. */ 00093 int constellation_state; 00094 00095 /*! \brief The current phase of the carrier (i.e. the DDS parameter). */ 00096 uint32_t carrier_phase; 00097 /*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */ 00098 int32_t carrier_phase_rate; 00099 /*! \brief The carrier update rate saved for reuse when using short training. */ 00100 int32_t carrier_phase_rate_save; 00101 #if defined(SPANDSP_USE_FIXED_POINT) 00102 /*! \brief The proportional part of the carrier tracking filter. */ 00103 int32_t carrier_track_p; 00104 /*! \brief The integral part of the carrier tracking filter. */ 00105 int32_t carrier_track_i; 00106 #else 00107 /*! \brief The proportional part of the carrier tracking filter. */ 00108 float carrier_track_p; 00109 /*! \brief The integral part of the carrier tracking filter. */ 00110 float carrier_track_i; 00111 #endif 00112 00113 /*! \brief A power meter, to measure the HPF'ed signal power in the channel. */ 00114 power_meter_t power; 00115 /*! \brief The power meter level at which carrier on is declared. */ 00116 int32_t carrier_on_power; 00117 /*! \brief The power meter level at which carrier off is declared. */ 00118 int32_t carrier_off_power; 00119 00120 /*! \brief Current read offset into the equalizer buffer. */ 00121 int eq_step; 00122 /*! \brief Current write offset into the equalizer buffer. */ 00123 int eq_put_step; 00124 /*! \brief Symbol counter to the next equalizer update. */ 00125 int eq_skip; 00126 00127 /*! \brief The current half of the baud. */ 00128 int baud_half; 00129 00130 #if defined(SPANDSP_USE_FIXED_POINT) 00131 /*! \brief The scaling factor accessed by the AGC algorithm. */ 00132 int16_t agc_scaling; 00133 /*! \brief The previous value of agc_scaling, needed to reuse old training. */ 00134 int16_t agc_scaling_save; 00135 00136 /*! \brief The current delta factor for updating the equalizer coefficients. */ 00137 int16_t eq_delta; 00138 /*! \brief The adaptive equalizer coefficients. */ 00139 complexi16_t eq_coeff[V29_EQUALIZER_PRE_LEN + 1 + V29_EQUALIZER_POST_LEN]; 00140 /*! \brief A saved set of adaptive equalizer coefficients for use after restarts. */ 00141 complexi16_t eq_coeff_save[V29_EQUALIZER_PRE_LEN + 1 + V29_EQUALIZER_POST_LEN]; 00142 /*! \brief The equalizer signal buffer. */ 00143 complexi16_t eq_buf[V29_EQUALIZER_PRE_LEN + 1 + V29_EQUALIZER_POST_LEN]; 00144 00145 /*! Low band edge filter for symbol sync. */ 00146 int32_t symbol_sync_low[2]; 00147 /*! High band edge filter for symbol sync. */ 00148 int32_t symbol_sync_high[2]; 00149 /*! DC filter for symbol sync. */ 00150 int32_t symbol_sync_dc_filter[2]; 00151 /*! Baud phase for symbol sync. */ 00152 int32_t baud_phase; 00153 #else 00154 /*! \brief The scaling factor accessed by the AGC algorithm. */ 00155 float agc_scaling; 00156 /*! \brief The previous value of agc_scaling, needed to reuse old training. */ 00157 float agc_scaling_save; 00158 00159 /*! \brief The current delta factor for updating the equalizer coefficients. */ 00160 float eq_delta; 00161 /*! \brief The adaptive equalizer coefficients. */ 00162 complexf_t eq_coeff[V29_EQUALIZER_PRE_LEN + 1 + V29_EQUALIZER_POST_LEN]; 00163 /*! \brief A saved set of adaptive equalizer coefficients for use after restarts. */ 00164 complexf_t eq_coeff_save[V29_EQUALIZER_PRE_LEN + 1 + V29_EQUALIZER_POST_LEN]; 00165 /*! \brief The equalizer signal buffer. */ 00166 complexf_t eq_buf[V29_EQUALIZER_PRE_LEN + 1 + V29_EQUALIZER_POST_LEN]; 00167 00168 /*! Low band edge filter for symbol sync. */ 00169 float symbol_sync_low[2]; 00170 /*! High band edge filter for symbol sync. */ 00171 float symbol_sync_high[2]; 00172 /*! DC filter for symbol sync. */ 00173 float symbol_sync_dc_filter[2]; 00174 /*! Baud phase for symbol sync. */ 00175 float baud_phase; 00176 #endif 00177 00178 /*! \brief The total symbol timing correction since the carrier came up. 00179 This is only for performance analysis purposes. */ 00180 int total_baud_timing_correction; 00181 00182 /*! \brief Starting phase angles for the coarse carrier aquisition step. */ 00183 int32_t start_angles[2]; 00184 /*! \brief History list of phase angles for the coarse carrier aquisition step. */ 00185 int32_t angles[16]; 00186 /*! \brief Error and flow logging control */ 00187 logging_state_t logging; 00188 }; 00189 00190 #endif 00191 /*- End of file ------------------------------------------------------------*/