private/v27ter_tx.h

00001 /*
00002  * SpanDSP - a series of DSP components for telephony
00003  *
00004  * private/v27ter_tx.h - ITU V.27ter modem transmit 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 
00026 #if !defined(_SPANDSP_PRIVATE_V27TER_TX_H_)
00027 #define _SPANDSP_PRIVATE_V27TER_TX_H_
00028 
00029 /*! The number of taps in the pulse shaping/bandpass filter */
00030 #define V27TER_TX_FILTER_STEPS      9
00031 
00032 /*!
00033     V.27ter modem transmit side descriptor. This defines the working state for a
00034     single instance of a V.27ter modem transmitter.
00035 */
00036 struct v27ter_tx_state_s
00037 {
00038     /*! \brief The bit rate of the modem. Valid values are 2400 and 4800. */
00039     int bit_rate;
00040     /*! \brief The callback function used to get the next bit to be transmitted. */
00041     get_bit_func_t get_bit;
00042     /*! \brief A user specified opaque pointer passed to the get_bit function. */
00043     void *get_bit_user_data;
00044 
00045     /*! \brief The callback function used to report modem status changes. */
00046     modem_tx_status_func_t status_handler;
00047     /*! \brief A user specified opaque pointer passed to the status function. */
00048     void *status_user_data;
00049 
00050 #if defined(SPANDSP_USE_FIXED_POINT)
00051     /*! \brief The gain factor needed to achieve the specified output power at 2400bps. */
00052     int32_t gain_2400;
00053     /*! \brief The gain factor needed to achieve the specified output power at 4800bps. */
00054     int32_t gain_4800;
00055 #else
00056     /*! \brief The gain factor needed to achieve the specified output power at 2400bps. */
00057     float gain_2400;
00058     /*! \brief The gain factor needed to achieve the specified output power at 4800bps. */
00059     float gain_4800;
00060 #endif
00061     /*! \brief The route raised cosine (RRC) pulse shaping filter buffer. */
00062 #if defined(SPANDSP_USE_FIXED_POINT)
00063     complexi16_t rrc_filter[2*V27TER_TX_FILTER_STEPS];
00064 #else
00065     complexf_t rrc_filter[2*V27TER_TX_FILTER_STEPS];
00066 #endif
00067     /*! \brief Current offset into the RRC pulse shaping filter buffer. */
00068     int rrc_filter_step;
00069     
00070     /*! \brief The register for the training and data scrambler. */
00071     unsigned int scramble_reg;
00072     /*! \brief A counter for the number of consecutive bits of repeating pattern through
00073                the scrambler. */
00074     int scrambler_pattern_count;
00075     /*! \brief TRUE if transmitting the training sequence, or shutting down transmission.
00076                FALSE if transmitting user data. */
00077     int in_training;
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     /*! \brief The get_bit function in use at any instant. */
00090     get_bit_func_t current_get_bit;
00091     /*! \brief Error and flow logging control */
00092     logging_state_t logging;
00093 };
00094 
00095 #endif
00096 /*- End of file ------------------------------------------------------------*/

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