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_TIMED_SILENCE,
59 V22BIS_TX_TRAINING_STAGE_INITIAL_SILENCE,
60 V22BIS_TX_TRAINING_STAGE_U11,
61 V22BIS_TX_TRAINING_STAGE_U0011,
62 V22BIS_TX_TRAINING_STAGE_S11,
63 V22BIS_TX_TRAINING_STAGE_TIMED_S11,
64 V22BIS_TX_TRAINING_STAGE_S1111,
65 V22BIS_TX_TRAINING_STAGE_PARKED
66};
67
68#if defined(SPANDSP_USE_FIXED_POINT)
69extern const complexi16_t v22bis_constellation[16];
70#else
71extern const complexf_t v22bis_constellation[16];
72#endif
73
74/*!
75 V.22bis modem descriptor. This defines the working state for a single instance
76 of a V.22bis modem.
77*/
79{
80 /*! \brief The maximum permitted bit rate of the modem. Valid values are 1200 and 2400. */
82 /*! \brief True is this is the calling side modem. */
84 /*! \brief The callback function used to get the next bit to be transmitted. */
86 /*! \brief A user specified opaque pointer passed to the get_bit callback routine. */
88 /*! \brief The callback function used to put each bit received. */
90 /*! \brief A user specified opaque pointer passed to the put_bit callback routine. */
92 /*! \brief The callback function used to report modem status changes. */
94 /*! \brief A user specified opaque pointer passed to the status function. */
96
97 int negotiated_bit_rate;
98
99 /* Receive section */
100 struct
101 {
102 /*! \brief Current offset into the RRC pulse shaping filter buffer. */
104
105 /*! \brief The register for the data scrambler. */
106 uint32_t scramble_reg;
107 /*! \brief A counter for the number of consecutive bits of repeating pattern through
108 the scrambler. */
110
111 /*! \brief 0 if receiving user data. A training stage value during training */
113 /*! \brief A count of how far through the current training step we are. */
115
116 /*! \brief >0 if a signal above the minimum is present. It may or may not be a V.22bis signal. */
118
119 /*! \brief The current phase of the carrier (i.e. the DDS parameter). */
121 /*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */
123
124 /*! \brief A callback function which may be enabled to report every symbol's
125 constellation position. */
126 qam_report_handler_t qam_report;
127 /*! \brief A user specified opaque pointer passed to the qam_report callback
128 routine. */
130
131 /*! \brief A power meter, to measure the HPF'ed signal power in the channel. */
133 /*! \brief The power meter level at which carrier on is declared. */
135 /*! \brief The power meter level at which carrier off is declared. */
137
139
140#if defined(SPANDSP_USE_FIXED_POINT)
141 /*! \brief The scaling factor assessed by the AGC algorithm. */
142 int16_t agc_scaling;
143 /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
144 int16_t rrc_filter[V22BIS_RX_FILTER_STEPS];
145
146 /*! \brief The current delta factor for updating the equalizer coefficients. */
147 int16_t eq_delta;
148 /*! \brief The adaptive equalizer coefficients. */
149 complexi16_t eq_coeff[V22BIS_EQUALIZER_LEN];
150 /*! \brief The equalizer signal buffer. */
151 complexi16_t eq_buf[V22BIS_EQUALIZER_LEN];
152
153 /*! \brief A measure of how much mismatch there is between the real constellation,
154 and the decoded symbol positions. */
155 int32_t training_error;
156 /*! \brief The proportional part of the carrier tracking filter. */
157 int32_t carrier_track_p;
158 /*! \brief The integral part of the carrier tracking filter. */
159 int32_t carrier_track_i;
160#else
161 /*! \brief The scaling factor assessed by the AGC algorithm. */
163 /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
164 float rrc_filter[V22BIS_RX_FILTER_STEPS];
165
166 /*! \brief The current delta factor for updating the equalizer coefficients. */
167 float eq_delta;
168 /*! \brief The adaptive equalizer coefficients. */
169 complexf_t eq_coeff[V22BIS_EQUALIZER_LEN];
170 /*! \brief The equalizer signal buffer. */
171 complexf_t eq_buf[V22BIS_EQUALIZER_LEN];
172
173 /*! \brief A measure of how much mismatch there is between the real constellation,
174 and the decoded symbol positions. */
176 /*! \brief The proportional part of the carrier tracking filter. */
178 /*! \brief The integral part of the carrier tracking filter. */
180#endif
181 /*! \brief Current offset into the equalizer buffer. */
183 /*! \brief Current write offset into the equalizer buffer. */
185
186 /*! \brief Integration variable for damping the Gardner algorithm tests. */
188 /*! \brief Current step size of Gardner algorithm integration. */
190 /*! \brief The total symbol timing correction since the carrier came up.
191 This is only for performance analysis purposes. */
193 /*! \brief The current fractional phase of the baud timing. */
195
196 int sixteen_way_decisions;
197
198 int pattern_repeats;
199 int last_raw_bits;
200 } rx;
201
202 /* Transmit section */
203 struct
204 {
205#if defined(SPANDSP_USE_FIXED_POINT)
206 /*! \brief The guard tone level. */
207 int16_t guard_tone_gain;
208 /*! \brief The gain factor needed to achieve the specified output power. */
209 int16_t gain;
210 /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
211 int16_t rrc_filter_re[V22BIS_TX_FILTER_STEPS];
212 int16_t rrc_filter_im[V22BIS_TX_FILTER_STEPS];
213#else
214 /*! \brief The guard tone level. */
216 /*! \brief The gain factor needed to achieve the specified output power. */
217 float gain;
218 /*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
219 float rrc_filter_re[V22BIS_TX_FILTER_STEPS];
220 float rrc_filter_im[V22BIS_TX_FILTER_STEPS];
221#endif
222
223 /*! \brief Current offset into the RRC pulse shaping filter buffer. */
224 int rrc_filter_step;
225
226 /*! \brief The register for the data scrambler. */
227 uint32_t scramble_reg;
228 /*! \brief A counter for the number of consecutive bits of repeating pattern through
229 the scrambler. */
231
232 /*! \brief 0 if transmitting user data. A training stage value during training */
233 int training;
234 /*! \brief A counter used to track progress through sending the training sequence. */
235 int training_count;
236 /*! \brief The current phase of the carrier (i.e. the DDS parameter). */
237 uint32_t carrier_phase;
238 /*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */
239 int32_t carrier_phase_rate;
240 /*! \brief The current phase of the guard tone (i.e. the DDS parameter). */
241 uint32_t guard_phase;
242 /*! \brief The update rate for the phase of the guard tone (i.e. the DDS increment). */
244 /*! \brief The current fractional phase of the baud timing. */
245 int baud_phase;
246 /*! \brief The code number for the current position in the constellation. */
248 /*! \brief An indicator to mark that we are tidying up to stop transmission. */
250 /*! \brief The get_bit function in use at any instant. */
252 } tx;
253
254 /*! \brief Error and flow logging control */
256};
257
258#if defined(__cplusplus)
259extern "C"
260{
261#endif
262
263/*! Reinitialise an existing V.22bis modem receive context.
264 \brief Reinitialise an existing V.22bis modem receive context.
265 \param s The modem context.
266 \return 0 for OK, -1 for bad parameter */
268
269void v22bis_report_status_change(v22bis_state_t *s, int status);
270
271void v22bis_equalizer_coefficient_reset(v22bis_state_t *s);
272
273#if defined(__cplusplus)
274}
275#endif
276
277#endif
278/*- End of file ------------------------------------------------------------*/
void(* modem_status_func_t)(void *user_data, int status)
Definition: async.h:113
void(* put_bit_func_t)(void *user_data, int bit)
Definition: async.h:107
int(* get_bit_func_t)(void *user_data)
Definition: async.h:110
Definition: complex.h:43
Definition: complex.h:89
Definition: private/logging.h:34
Definition: private/power_meter.h:34
Definition: private/v22bis.h:79
logging_state_t logging
Error and flow logging control.
Definition: private/v22bis.h:255
int baud_phase
The current fractional phase of the baud timing.
Definition: private/v22bis.h:194
int bit_rate
The maximum permitted bit rate of the modem. Valid values are 1200 and 2400.
Definition: private/v22bis.h:81
get_bit_func_t current_get_bit
The get_bit function in use at any instant.
Definition: private/v22bis.h:251
float guard_tone_gain
The guard tone level.
Definition: private/v22bis.h:215
float rrc_filter_re[9]
The root raised cosine (RRC) pulse shaping filter buffer.
Definition: private/v22bis.h:219
int eq_put_step
Current write offset into the equalizer buffer.
Definition: private/v22bis.h:184
float rrc_filter[27]
The root raised cosine (RRC) pulse shaping filter buffer.
Definition: private/v22bis.h:164
qam_report_handler_t qam_report
A callback function which may be enabled to report every symbol's constellation position.
Definition: private/v22bis.h:126
int constellation_state
The code number for the current position in the constellation.
Definition: private/v22bis.h:138
complexf_t eq_coeff[17]
The adaptive equalizer coefficients.
Definition: private/v22bis.h:169
int training_count
A count of how far through the current training step we are.
Definition: private/v22bis.h:114
float gain
The gain factor needed to achieve the specified output power.
Definition: private/v22bis.h:217
void * status_user_data
A user specified opaque pointer passed to the status function.
Definition: private/v22bis.h:95
int scrambler_pattern_count
A counter for the number of consecutive bits of repeating pattern through the scrambler.
Definition: private/v22bis.h:109
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:192
void * qam_user_data
A user specified opaque pointer passed to the qam_report callback routine.
Definition: private/v22bis.h:129
bool calling_party
True is this is the calling side modem.
Definition: private/v22bis.h:83
int shutdown
An indicator to mark that we are tidying up to stop transmission.
Definition: private/v22bis.h:249
void * put_bit_user_data
A user specified opaque pointer passed to the put_bit callback routine.
Definition: private/v22bis.h:91
int gardner_integrate
Integration variable for damping the Gardner algorithm tests.
Definition: private/v22bis.h:187
float eq_delta
The current delta factor for updating the equalizer coefficients.
Definition: private/v22bis.h:167
int training
0 if receiving user data. A training stage value during training
Definition: private/v22bis.h:112
uint32_t guard_phase
The current phase of the guard tone (i.e. the DDS parameter).
Definition: private/v22bis.h:241
int32_t carrier_on_power
The power meter level at which carrier on is declared.
Definition: private/v22bis.h:134
power_meter_t rx_power
A power meter, to measure the HPF'ed signal power in the channel.
Definition: private/v22bis.h:132
float carrier_track_p
The proportional part of the carrier tracking filter.
Definition: private/v22bis.h:177
float agc_scaling
The scaling factor assessed by the AGC algorithm.
Definition: private/v22bis.h:162
put_bit_func_t put_bit
The callback function used to put each bit received.
Definition: private/v22bis.h:89
uint32_t carrier_phase
The current phase of the carrier (i.e. the DDS parameter).
Definition: private/v22bis.h:120
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:117
modem_status_func_t status_handler
The callback function used to report modem status changes.
Definition: private/v22bis.h:93
int eq_step
Current offset into the equalizer buffer.
Definition: private/v22bis.h:182
int gardner_step
Current step size of Gardner algorithm integration.
Definition: private/v22bis.h:189
uint32_t scramble_reg
The register for the data scrambler.
Definition: private/v22bis.h:106
int rrc_filter_step
Current offset into the RRC pulse shaping filter buffer.
Definition: private/v22bis.h:103
void * get_bit_user_data
A user specified opaque pointer passed to the get_bit callback routine.
Definition: private/v22bis.h:87
int32_t guard_phase_rate
The update rate for the phase of the guard tone (i.e. the DDS increment).
Definition: private/v22bis.h:243
int32_t carrier_phase_rate
The update rate for the phase of the carrier (i.e. the DDS increment).
Definition: private/v22bis.h:122
int32_t carrier_off_power
The power meter level at which carrier off is declared.
Definition: private/v22bis.h:136
get_bit_func_t get_bit
The callback function used to get the next bit to be transmitted.
Definition: private/v22bis.h:85
complexf_t eq_buf[17]
The equalizer signal buffer.
Definition: private/v22bis.h:171
float training_error
A measure of how much mismatch there is between the real constellation, and the decoded symbol positi...
Definition: private/v22bis.h:175
float carrier_track_i
The integral part of the carrier tracking filter.
Definition: private/v22bis.h:179
int v22bis_rx_restart(v22bis_state_t *s)
Reinitialise an existing V.22bis modem receive context.
Definition: v22bis_rx.c:944