spandsp 3.0.0
private/v22bis.h
1/*
2 * SpanDSP - a series of DSP components for telephony
3 *
4 * private/v22bis.h - ITU V.22bis modem
5 *
6 * Written by Steve Underwood <steveu@coppice.org>
7 *
8 * Copyright (C) 2004 Steve Underwood
9 *
10 * All rights reserved.
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Lesser General Public License version 2.1,
14 * as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26#if !defined(_SPANDSP_PRIVATE_V22BIS_H_)
27#define _SPANDSP_PRIVATE_V22BIS_H_
28
29/*! The length of the equalizer buffer */
30#define V22BIS_EQUALIZER_LEN 17
31/*! Samples before the target position in the equalizer buffer */
32#define V22BIS_EQUALIZER_PRE_LEN 8
33
34/*! The number of taps in the transmit pulse shaping filter */
35#define V22BIS_TX_FILTER_STEPS 9
36
37/*! The number of taps in the receive pulse shaping/bandpass filter */
38#define V22BIS_RX_FILTER_STEPS 27
39
40/*! Segments of the training sequence on the receive side */
41enum
42{
43 V22BIS_RX_TRAINING_STAGE_NORMAL_OPERATION,
44 V22BIS_RX_TRAINING_STAGE_SYMBOL_ACQUISITION,
45 V22BIS_RX_TRAINING_STAGE_LOG_PHASE,
46 V22BIS_RX_TRAINING_STAGE_UNSCRAMBLED_ONES,
47 V22BIS_RX_TRAINING_STAGE_UNSCRAMBLED_ONES_SUSTAINING,
48 V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200,
49 V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200_SUSTAINING,
50 V22BIS_RX_TRAINING_STAGE_WAIT_FOR_SCRAMBLED_ONES_AT_2400,
51 V22BIS_RX_TRAINING_STAGE_PARKED
52};
53
54/*! Segments of the training sequence on the transmit side */
55enum
56{
57 V22BIS_TX_TRAINING_STAGE_NORMAL_OPERATION = 0,
58 V22BIS_TX_TRAINING_STAGE_INITIAL_SILENCE, /* Initial calling side state */
59 V22BIS_TX_TRAINING_STAGE_INITIAL_TIMED_SILENCE, /* Initial V,22bis answering side state */
60 V22BIS_TX_TRAINING_STAGE_U11,
61 V22BIS_TX_TRAINING_STAGE_U00, /* A special feature for testing purposes. */
62 V22BIS_TX_TRAINING_STAGE_U0011,
63 V22BIS_TX_TRAINING_STAGE_S11,
64 V22BIS_TX_TRAINING_STAGE_TIMED_S11,
65 V22BIS_TX_TRAINING_STAGE_S1111,
66 V22BIS_TX_TRAINING_STAGE_PARKED
67};
68
69#if defined(SPANDSP_USE_FIXED_POINT)
70extern const complexi16_t v22bis_constellation[16];
71#else
72extern const complexf_t v22bis_constellation[16];
73#endif
74
75/*!
76 V.22bis modem descriptor. This defines the working state for a single instance
77 of a V.22bis modem.
78*/
80{
81 /*! \brief The maximum permitted bit rate of the modem. Valid values are 1200 and 2400. */
83 /*! \brief Guard tone and sundry flags */
85 /*! \brief True if this is the calling side modem. */
87 /*! \brief The callback function used to get the next bit to be transmitted. */
89 /*! \brief A user specified opaque pointer passed to the get_bit callback routine. */
91 /*! \brief The callback function used to put each bit received. */
93 /*! \brief A user specified opaque pointer passed to the put_bit callback routine. */
95 /*! \brief The callback function used to report modem status changes. */
97 /*! \brief A user specified opaque pointer passed to the status function. */
99
100 int negotiated_bit_rate;
101
102 /* Receive section */
103 struct
104 {
105 /*! \brief Current offset into the RRC pulse shaping filter buffer. */
107
108 /*! \brief The register for the data scrambler. */
109 uint32_t scramble_reg;
110 /*! \brief A counter for the number of consecutive bits of repeating pattern through
111 the scrambler. */
113
114 /*! \brief 0 if receiving user data. A training stage value during training */
116 /*! \brief A count of how far through the current training step we are. */
118
119 /*! \brief >0 if a signal above the minimum is present. It may or may not be a V.22bis signal. */
121
122 /*! \brief The current phase of the carrier (i.e. the DDS parameter). */
124 /*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */
126
127 /*! \brief A callback function which may be enabled to report every symbol's
128 constellation position. */
129 qam_report_handler_t qam_report;
130 /*! \brief A user specified opaque pointer passed to the qam_report callback
131 routine. */
133
134 /*! \brief A power meter, to measure the HPF'ed signal power in the channel. */
135 power_meter_t rx_power;
136 /*! \brief The power meter level at which carrier on is declared. */
138 /*! \brief The power meter level at which carrier off is declared. */
140
142
143#if defined(SPANDSP_USE_FIXED_POINT)
144 /*! \brief The scaling factor assessed by the AGC algorithm. */
145 int16_t agc_scaling;
146 /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
147 int16_t rrc_filter[V22BIS_RX_FILTER_STEPS];
148
149 /*! \brief The current delta factor for updating the equalizer coefficients. */
150 int16_t eq_delta;
151 /*! \brief The adaptive equalizer coefficients. */
152 complexi16_t eq_coeff[V22BIS_EQUALIZER_LEN];
153 /*! \brief The equalizer signal buffer. */
154 complexi16_t eq_buf[V22BIS_EQUALIZER_LEN];
155
156 /*! \brief A measure of how much mismatch there is between the real constellation,
157 and the decoded symbol positions. */
158 int32_t training_error;
159 /*! \brief The proportional part of the carrier tracking filter. */
160 int32_t carrier_track_p;
161 /*! \brief The integral part of the carrier tracking filter. */
162 int32_t carrier_track_i;
163#else
164 /*! \brief The scaling factor assessed by the AGC algorithm. */
166 /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
167 float rrc_filter[V22BIS_RX_FILTER_STEPS];
168
169 /*! \brief The current delta factor for updating the equalizer coefficients. */
170 float eq_delta;
171 /*! \brief The adaptive equalizer coefficients. */
172 complexf_t eq_coeff[V22BIS_EQUALIZER_LEN];
173 /*! \brief The equalizer signal buffer. */
174 complexf_t eq_buf[V22BIS_EQUALIZER_LEN];
175
176 /*! \brief A measure of how much mismatch there is between the real constellation,
177 and the decoded symbol positions. */
179 /*! \brief The proportional part of the carrier tracking filter. */
181 /*! \brief The integral part of the carrier tracking filter. */
183#endif
184 /*! \brief Current offset into the equalizer buffer. */
186 /*! \brief Current write offset into the equalizer buffer. */
188
189 /*! \brief Integration variable for damping the Gardner algorithm tests. */
191 /*! \brief Current step size of Gardner algorithm integration. */
193 /*! \brief The total symbol timing correction since the carrier came up.
194 This is only for performance analysis purposes. */
196 /*! \brief The current fractional phase of the baud timing. */
198
199 int sixteen_way_decisions;
200
201 int pattern_repeats;
202 int last_raw_bits;
203 } rx;
204
205 /* Transmit section */
206 struct
207 {
208#if defined(SPANDSP_USE_FIXED_POINT)
209 /*! \brief The guard tone level. */
210 int16_t guard_tone_gain;
211 /*! \brief The gain factor needed to achieve the specified output power. */
212 int16_t gain;
213 /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
214 int16_t rrc_filter_re[V22BIS_TX_FILTER_STEPS];
215 int16_t rrc_filter_im[V22BIS_TX_FILTER_STEPS];
216#else
217 /*! \brief The guard tone level. */
219 /*! \brief The gain factor needed to achieve the specified output power. */
220 float gain;
221 /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
222 float rrc_filter_re[V22BIS_TX_FILTER_STEPS];
223 float rrc_filter_im[V22BIS_TX_FILTER_STEPS];
224#endif
225
226 /*! \brief Current offset into the RRC pulse shaping filter buffer. */
227 int rrc_filter_step;
228
229 /*! \brief The register for the data scrambler. */
230 uint32_t scramble_reg;
231 /*! \brief A counter for the number of consecutive bits of repeating pattern through
232 the scrambler. */
234
235 /*! \brief 0 if transmitting user data. A training stage value during training */
236 int training;
237 /*! \brief A counter used to track progress through sending the training sequence. */
238 int training_count;
239 /*! \brief The current phase of the carrier (i.e. the DDS parameter). */
240 uint32_t carrier_phase;
241 /*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */
242 int32_t carrier_phase_rate;
243 /*! \brief The current phase of the guard tone (i.e. the DDS parameter). */
245 /*! \brief The update rate for the phase of the guard tone (i.e. the DDS increment). */
247 /*! \brief The current fractional phase of the baud timing. */
248 int baud_phase;
249 /*! \brief The code number for the current position in the constellation. */
251 /*! \brief An indicator to mark that we are tidying up to stop transmission. */
253 /*! \brief The get_bit function in use at any instant. */
255 } tx;
256
257 /*! \brief Error and flow logging control */
259};
260
261#if defined(__cplusplus)
262extern "C"
263{
264#endif
265
266/*! Reinitialise an existing V.22bis modem receive context.
267 \brief Reinitialise an existing V.22bis modem receive context.
268 \param s The modem context.
269 \return 0 for OK, -1 for bad parameter */
270int v22bis_rx_restart(v22bis_state_t *s);
271
272void v22bis_report_status_change(v22bis_state_t *s, int status);
273
274void v22bis_equalizer_coefficient_reset(v22bis_state_t *s);
275
276#if defined(__cplusplus)
277}
278#endif
279
280#endif
281/*- End of file ------------------------------------------------------------*/
int(* span_get_bit_func_t)(void *user_data)
Definition async.h:127
void(* span_modem_status_func_t)(void *user_data, int status)
Definition async.h:131
void(* span_put_bit_func_t)(void *user_data, int bit)
Definition async.h:123
struct logging_state_s logging_state_t
Definition logging.h:72
Definition complex.h:43
Definition complex.h:89
Definition private/v22bis.h:80
logging_state_t logging
Error and flow logging control.
Definition private/v22bis.h:258
int baud_phase
The current fractional phase of the baud timing.
Definition private/v22bis.h:197
int bit_rate
The maximum permitted bit rate of the modem. Valid values are 1200 and 2400.
Definition private/v22bis.h:82
float guard_tone_gain
The guard tone level.
Definition private/v22bis.h:218
float rrc_filter_re[9]
The root raised cosine (RRC) pulse shaping filter buffer.
Definition private/v22bis.h:222
int eq_put_step
Current write offset into the equalizer buffer.
Definition private/v22bis.h:187
float rrc_filter[27]
The root raised cosine (RRC) pulse shaping filter buffer.
Definition private/v22bis.h:167
qam_report_handler_t qam_report
A callback function which may be enabled to report every symbol's constellation position.
Definition private/v22bis.h:129
int constellation_state
The code number for the current position in the constellation.
Definition private/v22bis.h:141
complexf_t eq_coeff[17]
The adaptive equalizer coefficients.
Definition private/v22bis.h:172
int training_count
A count of how far through the current training step we are.
Definition private/v22bis.h:117
float gain
The gain factor needed to achieve the specified output power.
Definition private/v22bis.h:220
void * status_user_data
A user specified opaque pointer passed to the status function.
Definition private/v22bis.h:98
int scrambler_pattern_count
A counter for the number of consecutive bits of repeating pattern through the scrambler.
Definition private/v22bis.h:112
int total_baud_timing_correction
The total symbol timing correction since the carrier came up. This is only for performance analysis p...
Definition private/v22bis.h:195
void * qam_user_data
A user specified opaque pointer passed to the qam_report callback routine.
Definition private/v22bis.h:132
bool calling_party
True if this is the calling side modem.
Definition private/v22bis.h:86
int32_t guard_tone_phase_rate
The update rate for the phase of the guard tone (i.e. the DDS increment).
Definition private/v22bis.h:246
int shutdown
An indicator to mark that we are tidying up to stop transmission.
Definition private/v22bis.h:252
void * put_bit_user_data
A user specified opaque pointer passed to the put_bit callback routine.
Definition private/v22bis.h:94
int gardner_integrate
Integration variable for damping the Gardner algorithm tests.
Definition private/v22bis.h:190
float eq_delta
The current delta factor for updating the equalizer coefficients.
Definition private/v22bis.h:170
span_get_bit_func_t get_bit
The callback function used to get the next bit to be transmitted.
Definition private/v22bis.h:88
span_get_bit_func_t current_get_bit
The get_bit function in use at any instant.
Definition private/v22bis.h:254
int training
0 if receiving user data. A training stage value during training
Definition private/v22bis.h:115
int32_t carrier_on_power
The power meter level at which carrier on is declared.
Definition private/v22bis.h:137
power_meter_t rx_power
A power meter, to measure the HPF'ed signal power in the channel.
Definition private/v22bis.h:135
float carrier_track_p
The proportional part of the carrier tracking filter.
Definition private/v22bis.h:180
uint32_t guard_tone_phase
The current phase of the guard tone (i.e. the DDS parameter).
Definition private/v22bis.h:244
float agc_scaling
The scaling factor assessed by the AGC algorithm.
Definition private/v22bis.h:165
uint32_t carrier_phase
The current phase of the carrier (i.e. the DDS parameter).
Definition private/v22bis.h:123
int signal_present
>0 if a signal above the minimum is present. It may or may not be a V.22bis signal.
Definition private/v22bis.h:120
span_modem_status_func_t status_handler
The callback function used to report modem status changes.
Definition private/v22bis.h:96
int options
Guard tone and sundry flags.
Definition private/v22bis.h:84
int eq_step
Current offset into the equalizer buffer.
Definition private/v22bis.h:185
int gardner_step
Current step size of Gardner algorithm integration.
Definition private/v22bis.h:192
uint32_t scramble_reg
The register for the data scrambler.
Definition private/v22bis.h:109
int rrc_filter_step
Current offset into the RRC pulse shaping filter buffer.
Definition private/v22bis.h:106
void * get_bit_user_data
A user specified opaque pointer passed to the get_bit callback routine.
Definition private/v22bis.h:90
int32_t carrier_phase_rate
The update rate for the phase of the carrier (i.e. the DDS increment).
Definition private/v22bis.h:125
int32_t carrier_off_power
The power meter level at which carrier off is declared.
Definition private/v22bis.h:139
span_put_bit_func_t put_bit
The callback function used to put each bit received.
Definition private/v22bis.h:92
complexf_t eq_buf[17]
The equalizer signal buffer.
Definition private/v22bis.h:174
float training_error
A measure of how much mismatch there is between the real constellation, and the decoded symbol positi...
Definition private/v22bis.h:178
float carrier_track_i
The integral part of the carrier tracking filter.
Definition private/v22bis.h:182
struct v22bis_state_s v22bis_state_t
Definition v22bis.h:83