--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/spandsp/private/v17rx.h	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,232 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * private/v17rx.h - ITU V.17 modem receive part
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2003 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.
+ *
+ * $Id: v17rx.h,v 1.2.4.1 2009/12/24 16:52:30 steveu Exp $
+ */
+
+#if !defined(_SPANDSP_PRIVATE_V17RX_H_)
+#define _SPANDSP_PRIVATE_V17RX_H_
+
+/* Target length for the equalizer is about 63 taps, to deal with the worst stuff
+   in V.56bis. */
+/*! Samples before the target position in the equalizer buffer */
+#define V17_EQUALIZER_PRE_LEN       8
+/*! Samples after the target position in the equalizer buffer */
+#define V17_EQUALIZER_POST_LEN      8
+
+/*! The number of taps in the pulse shaping/bandpass filter */
+#define V17_RX_FILTER_STEPS         27
+
+/* We can store more trellis depth that we look back over, so that we can push out a group
+   of symbols in one go, giving greater processing efficiency, at the expense of a bit more
+   latency through the modem. */
+/* Right now we don't take advantage of this optimisation. */
+/*! The depth of the trellis buffer */
+#define V17_TRELLIS_STORAGE_DEPTH   16
+/*! How far we look back into history for trellis decisions */
+#define V17_TRELLIS_LOOKBACK_DEPTH  16
+
+/*!
+    V.17 modem receive side descriptor. This defines the working state for a
+    single instance of a V.17 modem receiver.
+*/
+struct v17_rx_state_s
+{
+    /*! \brief The bit rate of the modem. Valid values are 7200 9600, 12000 and 14400. */
+    int bit_rate;
+    /*! \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_but routine. */
+    void *put_bit_user_data;
+
+    /*! \brief The callback function used to report modem status changes. */
+    modem_rx_status_func_t status_handler;
+    /*! \brief A user specified opaque pointer passed to the status function. */
+    void *status_user_data;
+
+    /*! \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 The route raised cosine (RRC) pulse shaping filter buffer. */
+#if defined(SPANDSP_USE_FIXED_POINT)
+    int16_t rrc_filter[V17_RX_FILTER_STEPS];
+#else
+    float rrc_filter[V17_RX_FILTER_STEPS];
+#endif
+    /*! \brief Current offset into the RRC pulse shaping filter buffer. */
+    int rrc_filter_step;
+
+    /*! \brief The state of the differential decoder */
+    int diff;
+    /*! \brief The register for the data scrambler. */
+    uint32_t scramble_reg;
+    /*! \brief Scrambler tap */
+    //int scrambler_tap;
+
+    /*! \brief TRUE if the short training sequence is to be used. */
+    int short_train;
+    /*! \brief The section of the training data we are currently in. */
+    int training_stage;
+    /*! \brief A count of how far through the current training step we are. */
+    int training_count;
+    /*! \brief A measure of how much mismatch there is between the real constellation,
+        and the decoded symbol positions. */
+    float training_error;
+    /*! \brief The value of the last signal sample, using the a simple HPF for signal power estimation. */
+    int16_t last_sample;
+    /*! \brief >0 if a signal above the minimum is present. It may or may not be a V.17 signal. */
+    int signal_present;
+    /*! \brief Whether or not a carrier drop was detected and the signal delivery is pending. */
+    int carrier_drop_pending;
+    /*! \brief A count of the current consecutive samples below the carrier off threshold. */
+    int low_samples;
+    /*! \brief A highest magnitude sample seen. */
+    int16_t high_sample;
+
+    /*! \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 carrier update rate saved for reuse when using short training. */
+    int32_t carrier_phase_rate_save;
+#if defined(SPANDSP_USE_FIXED_POINTx)
+    /*! \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 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 A power meter, to measure the HPF'ed signal power in the channel. */    
+    power_meter_t 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;
+
+    /*! \brief Current read offset into the equalizer buffer. */
+    int eq_step;
+    /*! \brief Current write offset into the equalizer buffer. */
+    int eq_put_step;
+    /*! \brief Symbol counter to the next equalizer update. */
+    int eq_skip;
+
+    /*! \brief The current half of the baud. */
+    int baud_half;
+
+#if defined(SPANDSP_USE_FIXED_POINTx)
+    /*! \brief The scaling factor accessed by the AGC algorithm. */
+    float agc_scaling;
+    /*! \brief The previous value of agc_scaling, needed to reuse old training. */
+    float agc_scaling_save;
+
+    /*! \brief The current delta factor for updating the equalizer coefficients. */
+    float eq_delta;
+    /*! \brief The adaptive equalizer coefficients. */
+    complexi16_t eq_coeff[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN];
+    /*! \brief A saved set of adaptive equalizer coefficients for use after restarts. */
+    complexi16_t eq_coeff_save[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN];
+    /*! \brief The equalizer signal buffer. */
+    complexi16_t eq_buf[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN];
+
+    /*! Low band edge filter for symbol sync. */
+    int32_t symbol_sync_low[2];
+    /*! High band edge filter for symbol sync. */
+    int32_t symbol_sync_high[2];
+    /*! DC filter for symbol sync. */
+    int32_t symbol_sync_dc_filter[2];
+    /*! Baud phase for symbol sync. */
+    int32_t baud_phase;
+#else
+    /*! \brief The scaling factor accessed by the AGC algorithm. */
+    float agc_scaling;
+    /*! \brief The previous value of agc_scaling, needed to reuse old training. */
+    float agc_scaling_save;
+
+    /*! \brief The current delta factor for updating the equalizer coefficients. */
+    float eq_delta;
+    /*! \brief The adaptive equalizer coefficients. */
+    complexf_t eq_coeff[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN];
+    /*! \brief A saved set of adaptive equalizer coefficients for use after restarts. */
+    complexf_t eq_coeff_save[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN];
+    /*! \brief The equalizer signal buffer. */
+    complexf_t eq_buf[V17_EQUALIZER_PRE_LEN + 1 + V17_EQUALIZER_POST_LEN];
+
+    /*! Low band edge filter for symbol sync. */
+    float symbol_sync_low[2];
+    /*! High band edge filter for symbol sync. */
+    float symbol_sync_high[2];
+    /*! DC filter for symbol sync. */
+    float symbol_sync_dc_filter[2];
+    /*! Baud phase for symbol sync. */
+    float baud_phase;
+#endif
+
+    /*! \brief The total symbol timing correction since the carrier came up.
+               This is only for performance analysis purposes. */
+    int total_baud_timing_correction;
+
+    /*! \brief Starting phase angles for the coarse carrier aquisition step. */
+    int32_t start_angles[2];
+    /*! \brief History list of phase angles for the coarse carrier aquisition step. */
+    int32_t angles[16];
+    /*! \brief A pointer to the current constellation. */
+#if defined(SPANDSP_USE_FIXED_POINTx)
+    const complexi16_t *constellation;
+#else
+    const complexf_t *constellation;
+#endif
+    /*! \brief A pointer to the current space map. There is a space map for
+               each trellis state. */
+    int space_map;
+    /*! \brief The number of bits in each symbol at the current bit rate. */
+    int bits_per_symbol;
+
+    /*! \brief Current pointer to the trellis buffers */
+    int trellis_ptr;
+    /*! \brief The trellis. */
+    int full_path_to_past_state_locations[V17_TRELLIS_STORAGE_DEPTH][8];
+    /*! \brief The trellis. */
+    int past_state_locations[V17_TRELLIS_STORAGE_DEPTH][8];
+    /*! \brief Euclidean distances (actually the squares of the distances)
+               from the last states of the trellis. */
+#if defined(SPANDSP_USE_FIXED_POINTx)
+    uint32_t distances[8];
+#else
+    float distances[8];
+#endif
+    /*! \brief Error and flow logging control */
+    logging_state_t logging;
+};
+
+#endif
+/*- End of file ------------------------------------------------------------*/