00001 /* 00002 * SpanDSP - a series of DSP components for telephony 00003 * 00004 * private/v17rx.h - ITU V.17 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: v17rx.h,v 1.1 2008/10/13 13:14:01 steveu Exp $ 00026 */ 00027 00028 #if !defined(_SPANDSP_PRIVATE_V17RX_H_) 00029 #define _SPANDSP_PRIVATE_V17RX_H_ 00030 00031 /*! 00032 V.17 modem receive side descriptor. This defines the working state for a 00033 single instance of a V.17 modem receiver. 00034 */ 00035 struct v17_rx_state_s 00036 { 00037 /*! \brief The bit rate of the modem. Valid values are 7200 9600, 12000 and 14400. */ 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_but 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[V17_RX_FILTER_STEPS]; 00059 #else 00060 float rrc_filter[V17_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 state of the differential decoder */ 00066 int diff; 00067 /*! \brief The register for the data scrambler. */ 00068 unsigned int scramble_reg; 00069 /*! \brief TRUE if the short training sequence is to be used. */ 00070 int short_train; 00071 /*! \brief The section of the training data we are currently in. */ 00072 int training_stage; 00073 /*! \brief A count of how far through the current training step we are. */ 00074 int training_count; 00075 /*! \brief A measure of how much mismatch there is between the real constellation, 00076 and the decoded symbol positions. */ 00077 float training_error; 00078 /*! \brief The value of the last signal sample, using the a simple HPF for signal power estimation. */ 00079 int16_t last_sample; 00080 /*! \brief >0 if a signal above the minimum is present. It may or may not be a V.17 signal. */ 00081 int signal_present; 00082 /*! \brief Whether or not a carrier drop was detected and the signal delivery is pending. */ 00083 int carrier_drop_pending; 00084 /*! \brief A count of the current consecutive samples below the carrier off threshold. */ 00085 int low_samples; 00086 /*! \brief A highest magnitude sample seen. */ 00087 int16_t high_sample; 00088 00089 /*! \brief The current phase of the carrier (i.e. the DDS parameter). */ 00090 uint32_t carrier_phase; 00091 /*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */ 00092 int32_t carrier_phase_rate; 00093 /*! \brief The carrier update rate saved for reuse when using short training. */ 00094 int32_t carrier_phase_rate_save; 00095 #if defined(SPANDSP_USE_FIXED_POINTx) 00096 /*! \brief The proportional part of the carrier tracking filter. */ 00097 float carrier_track_p; 00098 /*! \brief The integral part of the carrier tracking filter. */ 00099 float carrier_track_i; 00100 #else 00101 /*! \brief The proportional part of the carrier tracking filter. */ 00102 float carrier_track_p; 00103 /*! \brief The integral part of the carrier tracking filter. */ 00104 float carrier_track_i; 00105 #endif 00106 00107 /*! \brief A power meter, to measure the HPF'ed signal power in the channel. */ 00108 power_meter_t power; 00109 /*! \brief The power meter level at which carrier on is declared. */ 00110 int32_t carrier_on_power; 00111 /*! \brief The power meter level at which carrier off is declared. */ 00112 int32_t carrier_off_power; 00113 00114 /*! \brief Current read offset into the equalizer buffer. */ 00115 int eq_step; 00116 /*! \brief Current write offset into the equalizer buffer. */ 00117 int eq_put_step; 00118 /*! \brief Symbol counter to the next equalizer update. */ 00119 int eq_skip; 00120 00121 /*! \brief The current half of the baud. */ 00122 int baud_half; 00123 00124 #if defined(SPANDSP_USE_FIXED_POINTx) 00125 /*! \brief The scaling factor accessed by the AGC algorithm. */ 00126 float agc_scaling; 00127 /*! \brief The previous value of agc_scaling, needed to reuse old training. */ 00128 float agc_scaling_save; 00129 00130 /*! \brief The current delta factor for updating the equalizer coefficients. */ 00131 float eq_delta; 00132 /*! \brief The adaptive equalizer coefficients. */ 00133 complexi16_t eq_coeff[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN]; 00134 /*! \brief A saved set of adaptive equalizer coefficients for use after restarts. */ 00135 complexi16_t eq_coeff_save[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN]; 00136 /*! \brief The equalizer signal buffer. */ 00137 complexi16_t eq_buf[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN]; 00138 00139 /*! Low band edge filter for symbol sync. */ 00140 int32_t symbol_sync_low[2]; 00141 /*! High band edge filter for symbol sync. */ 00142 int32_t symbol_sync_high[2]; 00143 /*! DC filter for symbol sync. */ 00144 int32_t symbol_sync_dc_filter[2]; 00145 /*! Baud phase for symbol sync. */ 00146 int32_t baud_phase; 00147 #else 00148 /*! \brief The scaling factor accessed by the AGC algorithm. */ 00149 float agc_scaling; 00150 /*! \brief The previous value of agc_scaling, needed to reuse old training. */ 00151 float agc_scaling_save; 00152 00153 /*! \brief The current delta factor for updating the equalizer coefficients. */ 00154 float eq_delta; 00155 /*! \brief The adaptive equalizer coefficients. */ 00156 complexf_t eq_coeff[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN]; 00157 /*! \brief A saved set of adaptive equalizer coefficients for use after restarts. */ 00158 complexf_t eq_coeff_save[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN]; 00159 /*! \brief The equalizer signal buffer. */ 00160 complexf_t eq_buf[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN]; 00161 00162 /*! Low band edge filter for symbol sync. */ 00163 float symbol_sync_low[2]; 00164 /*! High band edge filter for symbol sync. */ 00165 float symbol_sync_high[2]; 00166 /*! DC filter for symbol sync. */ 00167 float symbol_sync_dc_filter[2]; 00168 /*! Baud phase for symbol sync. */ 00169 float baud_phase; 00170 #endif 00171 00172 /*! \brief The total symbol timing correction since the carrier came up. 00173 This is only for performance analysis purposes. */ 00174 int total_baud_timing_correction; 00175 00176 /*! \brief Starting phase angles for the coarse carrier aquisition step. */ 00177 int32_t start_angles[2]; 00178 /*! \brief History list of phase angles for the coarse carrier aquisition step. */ 00179 int32_t angles[16]; 00180 /*! \brief A pointer to the current constellation. */ 00181 #if defined(SPANDSP_USE_FIXED_POINTx) 00182 const complexi16_t *constellation; 00183 #else 00184 const complexf_t *constellation; 00185 #endif 00186 /*! \brief A pointer to the current space map. There is a space map for 00187 each trellis state. */ 00188 int space_map; 00189 /*! \brief The number of bits in each symbol at the current bit rate. */ 00190 int bits_per_symbol; 00191 00192 /*! \brief Current pointer to the trellis buffers */ 00193 int trellis_ptr; 00194 /*! \brief The trellis. */ 00195 int full_path_to_past_state_locations[V17_TRELLIS_STORAGE_DEPTH][8]; 00196 /*! \brief The trellis. */ 00197 int past_state_locations[V17_TRELLIS_STORAGE_DEPTH][8]; 00198 /*! \brief Euclidean distances (actually the squares of the distances) 00199 from the last states of the trellis. */ 00200 #if defined(SPANDSP_USE_FIXED_POINTx) 00201 uint32_t distances[8]; 00202 #else 00203 float distances[8]; 00204 #endif 00205 /*! \brief Error and flow logging control */ 00206 logging_state_t logging; 00207 }; 00208 00209 #endif 00210 /*- End of file ------------------------------------------------------------*/