private/v17tx.h

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00001 /*
00002  * SpanDSP - a series of DSP components for telephony
00003  *
00004  * private/v17tx.h - ITU V.17 modem transmit part
00005  *
00006  * Written by Steve Underwood <steveu@coppice.org>
00007  *
00008  * Copyright (C) 2004 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: v17tx.h,v 1.1 2008/10/13 13:14:01 steveu Exp $
00026  */
00027 
00028 /*! \file */
00029 
00030 #if !defined(_SPANDSP_PRIVATE_V17TX_H_)
00031 #define _SPANDSP_PRIVATE_V17TX_H_
00032 
00033 /*!
00034     V.17 modem transmit side descriptor. This defines the working state for a
00035     single instance of a V.17 modem transmitter.
00036 */
00037 struct v17_tx_state_s
00038 {
00039     /*! \brief The bit rate of the modem. Valid values are 4800, 7200 and 9600. */
00040     int bit_rate;
00041     /*! \brief The callback function used to get the next bit to be transmitted. */
00042     get_bit_func_t get_bit;
00043     /*! \brief A user specified opaque pointer passed to the get_bit function. */
00044     void *get_bit_user_data;
00045 
00046     /*! \brief The callback function used to report modem status changes. */
00047     modem_tx_status_func_t status_handler;
00048     /*! \brief A user specified opaque pointer passed to the status function. */
00049     void *status_user_data;
00050 
00051     /*! \brief The gain factor needed to achieve the specified output power. */
00052 #if defined(SPANDSP_USE_FIXED_POINT)
00053     int32_t gain;
00054 #else
00055     float gain;
00056 #endif
00057 
00058     /*! \brief The route raised cosine (RRC) pulse shaping filter buffer. */
00059 #if defined(SPANDSP_USE_FIXED_POINT)
00060     complexi16_t rrc_filter[2*V17_TX_FILTER_STEPS];
00061 #else
00062     complexf_t rrc_filter[2*V17_TX_FILTER_STEPS];
00063 #endif
00064     /*! \brief Current offset into the RRC pulse shaping filter buffer. */
00065     int rrc_filter_step;
00066 
00067     /*! \brief The current state of the differential encoder. */
00068     int diff;
00069     /*! \brief The current state of the convolutional encoder. */
00070     int convolution;
00071 
00072     /*! \brief The register for the data scrambler. */
00073     unsigned int scramble_reg;
00074     /*! \brief TRUE if transmitting the training sequence. FALSE if transmitting user data. */
00075     int in_training;
00076     /*! \brief TRUE if the short training sequence is to be used. */
00077     int short_train;
00078     /*! \brief A counter used to track progress through sending the training sequence. */
00079     int training_step;
00080 
00081     /*! \brief The current phase of the carrier (i.e. the DDS parameter). */
00082     uint32_t carrier_phase;
00083     /*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */
00084     int32_t carrier_phase_rate;
00085     /*! \brief The current fractional phase of the baud timing. */
00086     int baud_phase;
00087     /*! \brief The code number for the current position in the constellation. */
00088     int constellation_state;
00089     
00090     /*! \brief A pointer to the constellation currently in use. */
00091 #if defined(SPANDSP_USE_FIXED_POINT)
00092     const complexi16_t *constellation;
00093 #else
00094     const complexf_t *constellation;
00095 #endif
00096     /*! \brief The current number of data bits per symbol. This does not include
00097                the redundant bit. */
00098     int bits_per_symbol;
00099     /*! \brief The get_bit function in use at any instant. */
00100     get_bit_func_t current_get_bit;
00101     /*! \brief Error and flow logging control */
00102     logging_state_t logging;
00103 };
00104 
00105 #endif
00106 /*- End of file ------------------------------------------------------------*/

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