| File: | libs/spandsp/src/v22bis_rx.c |
| Location: | line 645, column 9 |
| Description: | Value stored to 'bitstream' is never read |
| 1 | /* |
| 2 | * SpanDSP - a series of DSP components for telephony |
| 3 | * |
| 4 | * v22bis_rx.c - ITU V.22bis modem receive part |
| 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 | /*! \file */ |
| 27 | |
| 28 | /* THIS IS A WORK IN PROGRESS - It is basically functional, but it is not feature |
| 29 | complete, and doesn't reliably sync over the signal and noise level ranges it |
| 30 | should. There are some nasty inefficiencies too! |
| 31 | TODO: |
| 32 | Better noise performance |
| 33 | Retrain is incomplete |
| 34 | Rate change is not implemented |
| 35 | Remote loopback is not implemented */ |
| 36 | |
| 37 | #if defined(HAVE_CONFIG_H1) |
| 38 | #include "config.h" |
| 39 | #endif |
| 40 | |
| 41 | #include <inttypes.h> |
| 42 | #include <string.h> |
| 43 | #include <stdio.h> |
| 44 | #include <stdlib.h> |
| 45 | #if defined(HAVE_TGMATH_H1) |
| 46 | #include <tgmath.h> |
| 47 | #endif |
| 48 | #if defined(HAVE_MATH_H1) |
| 49 | #include <math.h> |
| 50 | #endif |
| 51 | #if defined(HAVE_STDBOOL_H1) |
| 52 | #include <stdbool.h> |
| 53 | #else |
| 54 | #include "spandsp/stdbool.h" |
| 55 | #endif |
| 56 | #include "floating_fudge.h" |
| 57 | |
| 58 | #include "spandsp/telephony.h" |
| 59 | #include "spandsp/logging.h" |
| 60 | #include "spandsp/fast_convert.h" |
| 61 | #include "spandsp/math_fixed.h" |
| 62 | #include "spandsp/saturated.h" |
| 63 | #include "spandsp/complex.h" |
| 64 | #include "spandsp/vector_float.h" |
| 65 | #include "spandsp/complex_vector_float.h" |
| 66 | #include "spandsp/vector_int.h" |
| 67 | #include "spandsp/complex_vector_int.h" |
| 68 | #include "spandsp/async.h" |
| 69 | #include "spandsp/power_meter.h" |
| 70 | #include "spandsp/arctan2.h" |
| 71 | #include "spandsp/dds.h" |
| 72 | #include "spandsp/complex_filters.h" |
| 73 | |
| 74 | #include "spandsp/v29rx.h" |
| 75 | #include "spandsp/v22bis.h" |
| 76 | |
| 77 | #include "spandsp/private/logging.h" |
| 78 | #include "spandsp/private/power_meter.h" |
| 79 | #include "spandsp/private/v22bis.h" |
| 80 | |
| 81 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 82 | #define FP_SCALE(x)(x) FP_Q6_10(x)((int16_t) (1024.0*x + ((x >= 0.0) ? 0.5 : -0.5))) |
| 83 | #define FP_SHIFT_FACTOR 10 |
| 84 | #else |
| 85 | #define FP_SCALE(x)(x) (x) |
| 86 | #endif |
| 87 | |
| 88 | #include "v22bis_rx_1200_rrc.h" |
| 89 | #include "v22bis_rx_2400_rrc.h" |
| 90 | |
| 91 | #define ms_to_symbols(t)(((t)*600)/1000) (((t)*600)/1000) |
| 92 | |
| 93 | /*! The adaption rate coefficient for the equalizer */ |
| 94 | #define EQUALIZER_DELTA0.25f 0.25f |
| 95 | /*! The number of phase shifted coefficient set for the pulse shaping/bandpass filter */ |
| 96 | #define PULSESHAPER_COEFF_SETS12 12 |
| 97 | |
| 98 | /* |
| 99 | The basic method used by the V.22bis receiver is: |
| 100 | |
| 101 | Put each sample into the pulse-shaping and phase shift filter buffer |
| 102 | |
| 103 | At T/2 rate: |
| 104 | Filter and demodulate the contents of the input filter buffer, producing a sample |
| 105 | in the equalizer filter buffer. |
| 106 | |
| 107 | Tune the symbol timing based on the latest 3 samples in the equalizer buffer. This |
| 108 | updates the decision points for taking the T/2 samples. |
| 109 | |
| 110 | Equalize the contents of the equalizer buffer, producing a demodulated constellation |
| 111 | point. |
| 112 | |
| 113 | Find the nearest constellation point to the received position. This is our received |
| 114 | symbol. |
| 115 | |
| 116 | Tune the local carrier, based on the angular mismatch between the actual signal and |
| 117 | the decision. |
| 118 | |
| 119 | Tune the equalizer, based on the mismatch between the actual signal and the decision. |
| 120 | |
| 121 | Descramble and output the bits represented by the decision. |
| 122 | */ |
| 123 | |
| 124 | static const uint8_t space_map_v22bis[6][6] = |
| 125 | { |
| 126 | {11, 9, 9, 6, 6, 7}, |
| 127 | {10, 8, 8, 4, 4, 5}, |
| 128 | {10, 8, 8, 4, 4, 5}, |
| 129 | {13, 12, 12, 0, 0, 2}, |
| 130 | {13, 12, 12, 0, 0, 2}, |
| 131 | {15, 14, 14, 1, 1, 3} |
| 132 | }; |
| 133 | |
| 134 | static const uint8_t phase_steps[4] = |
| 135 | { |
| 136 | 1, 0, 2, 3 |
| 137 | }; |
| 138 | |
| 139 | SPAN_DECLARE(float)__attribute__((visibility("default"))) float v22bis_rx_carrier_frequency(v22bis_state_t *s) |
| 140 | { |
| 141 | return dds_frequencyf(s->rx.carrier_phase_rate); |
| 142 | } |
| 143 | /*- End of function --------------------------------------------------------*/ |
| 144 | |
| 145 | SPAN_DECLARE(float)__attribute__((visibility("default"))) float v22bis_rx_symbol_timing_correction(v22bis_state_t *s) |
| 146 | { |
| 147 | return (float) s->rx.total_baud_timing_correction/((float) PULSESHAPER_COEFF_SETS12*40.0f/(3.0f*2.0f)); |
| 148 | } |
| 149 | /*- End of function --------------------------------------------------------*/ |
| 150 | |
| 151 | SPAN_DECLARE(float)__attribute__((visibility("default"))) float v22bis_rx_signal_power(v22bis_state_t *s) |
| 152 | { |
| 153 | return power_meter_current_dbm0(&s->rx.rx_power) + 6.34f; |
| 154 | } |
| 155 | /*- End of function --------------------------------------------------------*/ |
| 156 | |
| 157 | SPAN_DECLARE(void)__attribute__((visibility("default"))) void v22bis_rx_signal_cutoff(v22bis_state_t *s, float cutoff) |
| 158 | { |
| 159 | s->rx.carrier_on_power = (int32_t) (power_meter_level_dbm0(cutoff + 2.5f)*0.232f); |
| 160 | s->rx.carrier_off_power = (int32_t) (power_meter_level_dbm0(cutoff - 2.5f)*0.232f); |
| 161 | } |
| 162 | /*- End of function --------------------------------------------------------*/ |
| 163 | |
| 164 | void v22bis_report_status_change(v22bis_state_t *s, int status) |
| 165 | { |
| 166 | if (s->status_handler) |
| 167 | s->status_handler(s->status_user_data, status); |
| 168 | else if (s->put_bit) |
| 169 | s->put_bit(s->put_bit_user_data, status); |
| 170 | } |
| 171 | /*- End of function --------------------------------------------------------*/ |
| 172 | |
| 173 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 174 | SPAN_DECLARE(int)__attribute__((visibility("default"))) int v22bis_rx_equalizer_state(v22bis_state_t *s, complexi16_t **coeffs) |
| 175 | #else |
| 176 | SPAN_DECLARE(int)__attribute__((visibility("default"))) int v22bis_rx_equalizer_state(v22bis_state_t *s, complexf_t **coeffs) |
| 177 | #endif |
| 178 | { |
| 179 | *coeffs = s->rx.eq_coeff; |
| 180 | return V22BIS_EQUALIZER_LEN17; |
| 181 | } |
| 182 | /*- End of function --------------------------------------------------------*/ |
| 183 | |
| 184 | void v22bis_equalizer_coefficient_reset(v22bis_state_t *s) |
| 185 | { |
| 186 | /* Start with an equalizer based on everything being perfect */ |
| 187 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 188 | static const complexi16_t x = {FP_Q6_10(3.0f)((int16_t) (1024.0*3.0f + ((3.0f >= 0.0) ? 0.5 : -0.5))), FP_Q6_10(0.0f)((int16_t) (1024.0*0.0f + ((0.0f >= 0.0) ? 0.5 : -0.5)))}; |
| 189 | |
| 190 | cvec_zeroi16(s->rx.eq_coeff, V22BIS_EQUALIZER_LEN17); |
| 191 | s->rx.eq_coeff[V22BIS_EQUALIZER_PRE_LEN8] = x; |
| 192 | s->rx.eq_delta = 32.0f*EQUALIZER_DELTA0.25f/V22BIS_EQUALIZER_LEN17; |
| 193 | #else |
| 194 | static const complexf_t x = {3.0f, 0.0f}; |
| 195 | |
| 196 | cvec_zerof(s->rx.eq_coeff, V22BIS_EQUALIZER_LEN17); |
| 197 | s->rx.eq_coeff[V22BIS_EQUALIZER_PRE_LEN8] = x; |
| 198 | s->rx.eq_delta = EQUALIZER_DELTA0.25f/V22BIS_EQUALIZER_LEN17; |
| 199 | #endif |
| 200 | } |
| 201 | /*- End of function --------------------------------------------------------*/ |
| 202 | |
| 203 | static void equalizer_reset(v22bis_state_t *s) |
| 204 | { |
| 205 | v22bis_equalizer_coefficient_reset(s); |
| 206 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 207 | cvec_zeroi16(s->rx.eq_buf, V22BIS_EQUALIZER_LEN17); |
| 208 | #else |
| 209 | cvec_zerof(s->rx.eq_buf, V22BIS_EQUALIZER_LEN17); |
| 210 | #endif |
| 211 | s->rx.eq_put_step = 20 - 1; |
| 212 | s->rx.eq_step = 0; |
| 213 | } |
| 214 | /*- End of function --------------------------------------------------------*/ |
| 215 | |
| 216 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 217 | static __inline__ complexi16_t equalizer_get(v22bis_state_t *s) |
| 218 | { |
| 219 | complexi32_t zz; |
| 220 | complexi16_t z; |
| 221 | |
| 222 | /* Get the next equalized value. */ |
| 223 | zz = cvec_circular_dot_prodi16(s->rx.eq_buf, s->rx.eq_coeff, V22BIS_EQUALIZER_LEN17, s->rx.eq_step); |
| 224 | z.re = zz.re >> FP_SHIFT_FACTOR; |
| 225 | z.im = zz.im >> FP_SHIFT_FACTOR; |
| 226 | return z; |
| 227 | } |
| 228 | #else |
| 229 | static __inline__ complexf_t equalizer_get(v22bis_state_t *s) |
| 230 | { |
| 231 | /* Get the next equalized value. */ |
| 232 | return cvec_circular_dot_prodf(s->rx.eq_buf, s->rx.eq_coeff, V22BIS_EQUALIZER_LEN17, s->rx.eq_step); |
| 233 | } |
| 234 | #endif |
| 235 | /*- End of function --------------------------------------------------------*/ |
| 236 | |
| 237 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 238 | static void tune_equalizer(v22bis_state_t *s, const complexi16_t *z, const complexi16_t *target) |
| 239 | { |
| 240 | complexi16_t err; |
| 241 | |
| 242 | /* Find the x and y mismatch from the exact constellation position. */ |
| 243 | err = complex_subi16(target, z); |
| 244 | err.re = ((int32_t) err.re*s->rx.eq_delta) >> 5; |
| 245 | err.im = ((int32_t) err.im*s->rx.eq_delta) >> 5; |
| 246 | //cvec_circular_lmsi16(s->rx.eq_buf, s->rx.eq_coeff, V22BIS_EQUALIZER_LEN, s->rx.eq_step, &err); |
| 247 | } |
| 248 | #else |
| 249 | static void tune_equalizer(v22bis_state_t *s, const complexf_t *z, const complexf_t *target) |
| 250 | { |
| 251 | complexf_t err; |
| 252 | |
| 253 | /* Find the x and y mismatch from the exact constellation position. */ |
| 254 | err = complex_subf(target, z); |
| 255 | err.re *= s->rx.eq_delta; |
| 256 | err.im *= s->rx.eq_delta; |
| 257 | cvec_circular_lmsf(s->rx.eq_buf, s->rx.eq_coeff, V22BIS_EQUALIZER_LEN17, s->rx.eq_step, &err); |
| 258 | } |
| 259 | #endif |
| 260 | /*- End of function --------------------------------------------------------*/ |
| 261 | |
| 262 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 263 | static __inline__ void track_carrier(v22bis_state_t *s, const complexi16_t *z, const complexi16_t *target) |
| 264 | #else |
| 265 | static __inline__ void track_carrier(v22bis_state_t *s, const complexf_t *z, const complexf_t *target) |
| 266 | #endif |
| 267 | { |
| 268 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 269 | int32_t error; |
| 270 | #else |
| 271 | float error; |
| 272 | #endif |
| 273 | |
| 274 | /* For small errors the imaginary part of the difference between the actual and the target |
| 275 | positions is proportional to the phase error, for any particular target. However, the |
| 276 | different amplitudes of the various target positions scale things. */ |
| 277 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 278 | error = ((int32_t) z->im*target->re - (int32_t) z->re*target->im) >> FP_SHIFT_FACTOR; |
| 279 | s->rx.carrier_phase_rate += (s->rx.carrier_track_i*error); |
| 280 | s->rx.carrier_phase += (s->rx.carrier_track_p*error); |
| 281 | //span_log(&s->logging, |
| 282 | // SPAN_LOG_FLOW, |
| 283 | // "CARR: Im = %15.5f f = %15.5f - %10d %10d\n", |
| 284 | // error/1024.0f, |
| 285 | // dds_frequency(s->rx.carrier_phase_rate), |
| 286 | // (s->rx.carrier_track_i*error), |
| 287 | // (s->rx.carrier_track_p*error)); |
| 288 | #else |
| 289 | error = z->im*target->re - z->re*target->im; |
| 290 | s->rx.carrier_phase_rate += (int32_t) (s->rx.carrier_track_i*error); |
| 291 | s->rx.carrier_phase += (int32_t) (s->rx.carrier_track_p*error); |
| 292 | //span_log(&s->logging, |
| 293 | // SPAN_LOG_FLOW, |
| 294 | // "CARR: Im = %15.5f f = %15.5f - %10d %10d\n", |
| 295 | // error, |
| 296 | // dds_frequencyf(s->rx.carrier_phase_rate), |
| 297 | // (int32_t) (s->rx.carrier_track_i*error), |
| 298 | // (int32_t) (s->rx.carrier_track_p*error)); |
| 299 | #endif |
| 300 | } |
| 301 | /*- End of function --------------------------------------------------------*/ |
| 302 | |
| 303 | static __inline__ int descramble(v22bis_state_t *s, int bit) |
| 304 | { |
| 305 | int out_bit; |
| 306 | |
| 307 | /* Descramble the bit */ |
| 308 | bit &= 1; |
| 309 | out_bit = (bit ^ (s->rx.scramble_reg >> 13) ^ (s->rx.scramble_reg >> 16)) & 1; |
| 310 | s->rx.scramble_reg = (s->rx.scramble_reg << 1) | bit; |
| 311 | |
| 312 | if (s->rx.scrambler_pattern_count >= 64) |
| 313 | { |
| 314 | out_bit ^= 1; |
| 315 | s->rx.scrambler_pattern_count = 0; |
| 316 | } |
| 317 | if (bit) |
| 318 | s->rx.scrambler_pattern_count++; |
| 319 | else |
| 320 | s->rx.scrambler_pattern_count = 0; |
| 321 | return out_bit; |
| 322 | } |
| 323 | /*- End of function --------------------------------------------------------*/ |
| 324 | |
| 325 | static __inline__ void put_bit(v22bis_state_t *s, int bit) |
| 326 | { |
| 327 | int out_bit; |
| 328 | |
| 329 | /* Descramble the bit */ |
| 330 | out_bit = descramble(s, bit); |
| 331 | s->put_bit(s->put_bit_user_data, out_bit); |
| 332 | } |
| 333 | /*- End of function --------------------------------------------------------*/ |
| 334 | |
| 335 | static void decode_baud(v22bis_state_t *s, int nearest) |
| 336 | { |
| 337 | int raw_bits; |
| 338 | |
| 339 | raw_bits = phase_steps[((nearest >> 2) - (s->rx.constellation_state >> 2)) & 3]; |
| 340 | s->rx.constellation_state = nearest; |
| 341 | /* The first two bits are the quadrant */ |
| 342 | put_bit(s, raw_bits >> 1); |
| 343 | put_bit(s, raw_bits); |
| 344 | if (s->rx.sixteen_way_decisions) |
| 345 | { |
| 346 | /* The other two bits are the position within the quadrant */ |
| 347 | put_bit(s, nearest >> 1); |
| 348 | put_bit(s, nearest); |
| 349 | } |
| 350 | } |
| 351 | /*- End of function --------------------------------------------------------*/ |
| 352 | |
| 353 | static int decode_baudx(v22bis_state_t *s, int nearest) |
| 354 | { |
| 355 | int raw_bits; |
| 356 | int out_bits; |
| 357 | |
| 358 | raw_bits = phase_steps[((nearest >> 2) - (s->rx.constellation_state >> 2)) & 3]; |
| 359 | s->rx.constellation_state = nearest; |
| 360 | /* The first two bits are the quadrant */ |
| 361 | out_bits = descramble(s, raw_bits >> 1); |
| 362 | out_bits = (out_bits << 1) | descramble(s, raw_bits); |
| 363 | if (s->rx.sixteen_way_decisions) |
| 364 | { |
| 365 | /* The other two bits are the position within the quadrant */ |
| 366 | out_bits = (out_bits << 1) | descramble(s, nearest >> 1); |
| 367 | out_bits = (out_bits << 1) | descramble(s, nearest); |
| 368 | } |
| 369 | return out_bits; |
| 370 | } |
| 371 | /*- End of function --------------------------------------------------------*/ |
| 372 | |
| 373 | static __inline__ void symbol_sync(v22bis_state_t *s) |
| 374 | { |
| 375 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 376 | int32_t p; |
| 377 | int32_t q; |
| 378 | complexi16_t a; |
| 379 | complexi16_t b; |
| 380 | complexi16_t c; |
| 381 | static const complexi16_t x = {FP_Q1_15(0.894427f)((int16_t) (32768.0*0.894427f + ((0.894427f >= 0.0) ? 0.5 : -0.5))), FP_Q1_15(0.44721f)((int16_t) (32768.0*0.44721f + ((0.44721f >= 0.0) ? 0.5 : - 0.5)))}; |
| 382 | #else |
| 383 | float p; |
| 384 | float q; |
| 385 | complexf_t a; |
| 386 | complexf_t b; |
| 387 | complexf_t c; |
| 388 | static const complexf_t x = {0.894427f, 0.44721f}; |
| 389 | #endif |
| 390 | int aa[3]; |
| 391 | int i; |
| 392 | int j; |
| 393 | |
| 394 | /* This routine adapts the position of the half baud samples entering the equalizer. */ |
| 395 | |
| 396 | /* Perform a Gardner test for baud alignment on the three most recent samples. */ |
| 397 | for (i = 0, j = s->rx.eq_step; i < 3; i++) |
| 398 | { |
| 399 | if (--j < 0) |
| 400 | j = V22BIS_EQUALIZER_LEN17 - 1; |
| 401 | aa[i] = j; |
| 402 | } |
| 403 | if (s->rx.sixteen_way_decisions) |
| 404 | { |
| 405 | p = s->rx.eq_buf[aa[2]].re - s->rx.eq_buf[aa[0]].re; |
| 406 | p *= s->rx.eq_buf[aa[1]].re; |
| 407 | |
| 408 | q = s->rx.eq_buf[aa[2]].im - s->rx.eq_buf[aa[0]].im; |
| 409 | q *= s->rx.eq_buf[aa[1]].im; |
| 410 | } |
| 411 | else |
| 412 | { |
| 413 | /* Rotate the points to the 45 degree positions, to maximise the effectiveness of |
| 414 | the Gardner algorithm. This is particularly significant at the start of operation |
| 415 | to pull things in quickly. */ |
| 416 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 417 | a = complex_mul_q1_15(&s->rx.eq_buf[aa[2]], &x); |
| 418 | b = complex_mul_q1_15(&s->rx.eq_buf[aa[1]], &x); |
| 419 | c = complex_mul_q1_15(&s->rx.eq_buf[aa[0]], &x); |
| 420 | #else |
| 421 | a = complex_mulf(&s->rx.eq_buf[aa[2]], &x); |
| 422 | b = complex_mulf(&s->rx.eq_buf[aa[1]], &x); |
| 423 | c = complex_mulf(&s->rx.eq_buf[aa[0]], &x); |
| 424 | #endif |
| 425 | p = (a.re - c.re)*b.re; |
| 426 | q = (a.im - c.im)*b.im; |
| 427 | } |
| 428 | |
| 429 | s->rx.gardner_integrate += (p + q > 0) ? s->rx.gardner_step : -s->rx.gardner_step; |
| 430 | |
| 431 | if (abs(s->rx.gardner_integrate) >= 16) |
| 432 | { |
| 433 | /* This integrate and dump approach avoids rapid changes of the equalizer put step. |
| 434 | Rapid changes, without hysteresis, are bad. They degrade the equalizer performance |
| 435 | when the true symbol boundary is close to a sample boundary. */ |
| 436 | s->rx.eq_put_step += (s->rx.gardner_integrate/16); |
| 437 | s->rx.total_baud_timing_correction += (s->rx.gardner_integrate/16); |
| 438 | //span_log(&s->logging, SPAN_LOG_FLOW, "Gardner kick %d [total %d]\n", s->rx.gardner_integrate, s->rx.total_baud_timing_correction); |
| 439 | if (s->rx.qam_report) |
| 440 | s->rx.qam_report(s->rx.qam_user_data, NULL((void*)0), NULL((void*)0), s->rx.gardner_integrate); |
| 441 | s->rx.gardner_integrate = 0; |
| 442 | } |
| 443 | } |
| 444 | /*- End of function --------------------------------------------------------*/ |
| 445 | |
| 446 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 447 | static __inline__ void process_half_baud(v22bis_state_t *s, const complexi16_t *sample) |
| 448 | #else |
| 449 | static __inline__ void process_half_baud(v22bis_state_t *s, const complexf_t *sample) |
| 450 | #endif |
| 451 | { |
| 452 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 453 | complexi16_t z; |
| 454 | complexi16_t zz; |
| 455 | const complexi16_t *target; |
| 456 | static const complexi16_t x = {FP_Q1_15(0.894427f)((int16_t) (32768.0*0.894427f + ((0.894427f >= 0.0) ? 0.5 : -0.5))), FP_Q1_15(0.44721f)((int16_t) (32768.0*0.44721f + ((0.44721f >= 0.0) ? 0.5 : - 0.5)))}; |
| 457 | #else |
| 458 | complexf_t z; |
| 459 | complexf_t zz; |
| 460 | const complexf_t *target; |
| 461 | static const complexf_t x = {0.894427f, 0.44721f}; |
| 462 | #endif |
| 463 | int re; |
| 464 | int im; |
| 465 | int nearest; |
| 466 | int bitstream; |
| 467 | int raw_bits; |
| 468 | |
| 469 | z.re = sample->re; |
| 470 | z.im = sample->im; |
| 471 | |
| 472 | /* Add a sample to the equalizer's circular buffer, but don't calculate anything |
| 473 | at this time. */ |
| 474 | s->rx.eq_buf[s->rx.eq_step] = z; |
| 475 | if (++s->rx.eq_step >= V22BIS_EQUALIZER_LEN17) |
| 476 | s->rx.eq_step = 0; |
| 477 | |
| 478 | /* On alternate insertions we have a whole baud and must process it. */ |
| 479 | if ((s->rx.baud_phase ^= 1)) |
| 480 | return; |
| 481 | |
| 482 | symbol_sync(s); |
| 483 | |
| 484 | z = equalizer_get(s); |
| 485 | |
| 486 | /* Find the constellation point */ |
| 487 | if (s->rx.sixteen_way_decisions) |
| 488 | { |
| 489 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 490 | re = (z.re + FP_Q6_10(3.0f)((int16_t) (1024.0*3.0f + ((3.0f >= 0.0) ? 0.5 : -0.5)))) >> FP_SHIFT_FACTOR; |
| 491 | im = (z.im + FP_Q6_10(3.0f)((int16_t) (1024.0*3.0f + ((3.0f >= 0.0) ? 0.5 : -0.5)))) >> FP_SHIFT_FACTOR; |
| 492 | #else |
| 493 | re = (int) (z.re + 3.0f); |
| 494 | im = (int) (z.im + 3.0f); |
| 495 | #endif |
| 496 | if (re > 5) |
| 497 | re = 5; |
| 498 | else if (re < 0) |
| 499 | re = 0; |
| 500 | if (im > 5) |
| 501 | im = 5; |
| 502 | else if (im < 0) |
| 503 | im = 0; |
| 504 | nearest = space_map_v22bis[re][im]; |
| 505 | } |
| 506 | else |
| 507 | { |
| 508 | /* Rotate to 45 degrees, to make the slicing trivial. */ |
| 509 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 510 | zz = complex_mul_q1_15(&z, &x); |
| 511 | #else |
| 512 | zz = complex_mulf(&z, &x); |
| 513 | #endif |
| 514 | nearest = 0x01; |
| 515 | if (zz.re < 0) |
| 516 | nearest |= 0x04; |
| 517 | if (zz.im < 0) |
| 518 | { |
| 519 | nearest ^= 0x04; |
| 520 | nearest |= 0x08; |
| 521 | } |
| 522 | } |
| 523 | raw_bits = 0; |
| 524 | |
| 525 | switch (s->rx.training) |
| 526 | { |
| 527 | case V22BIS_RX_TRAINING_STAGE_NORMAL_OPERATION: |
| 528 | /* Normal operation. */ |
| 529 | target = &v22bis_constellation[nearest]; |
| 530 | track_carrier(s, &z, target); |
| 531 | tune_equalizer(s, &z, target); |
| 532 | raw_bits = phase_steps[((nearest >> 2) - (s->rx.constellation_state >> 2)) & 3]; |
| 533 | /* TODO: detect unscrambled ones indicating a loopback request */ |
| 534 | |
| 535 | /* Search for the S1 signal that might be requesting a retrain */ |
| 536 | if ((s->rx.last_raw_bits ^ raw_bits) == 0x3) |
| 537 | { |
| 538 | s->rx.pattern_repeats++; |
| 539 | } |
| 540 | else |
| 541 | { |
| 542 | if (s->rx.pattern_repeats >= 50 && (s->rx.last_raw_bits == 0x3 || s->rx.last_raw_bits == 0x0)) |
| 543 | { |
| 544 | /* We should get a full run of 00 11 (about 60 bauds) at either modem. */ |
| 545 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ S1 detected (%d long)\n", s->rx.pattern_repeats); |
| 546 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ Accepting a retrain request\n"); |
| 547 | s->rx.pattern_repeats = 0; |
| 548 | s->rx.training_count = 0; |
| 549 | s->rx.training = V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200; |
| 550 | s->tx.training_count = 0; |
| 551 | s->tx.training = V22BIS_TX_TRAINING_STAGE_U0011; |
| 552 | v22bis_equalizer_coefficient_reset(s); |
| 553 | v22bis_report_status_change(s, SIG_STATUS_MODEM_RETRAIN_OCCURRED); |
| 554 | } |
| 555 | s->rx.pattern_repeats = 0; |
| 556 | } |
| 557 | decode_baud(s, nearest); |
| 558 | break; |
| 559 | case V22BIS_RX_TRAINING_STAGE_SYMBOL_ACQUISITION: |
| 560 | /* Allow time for the Gardner algorithm to settle the symbol timing. */ |
| 561 | target = &z; |
| 562 | if (++s->rx.training_count >= 40) |
| 563 | { |
| 564 | /* QAM and Gardner only play nicely with heavy damping, so we need to change to |
| 565 | a slow rate of symbol timing adaption. However, it must not be so slow that it |
| 566 | cannot track the worst case timing error specified in V.22bis. This should be 0.01%, |
| 567 | but since we might be off in the opposite direction from the source, the total |
| 568 | error could be higher. */ |
| 569 | s->rx.gardner_step = 4; |
| 570 | s->rx.pattern_repeats = 0; |
| 571 | s->rx.training = (s->calling_party) ? V22BIS_RX_TRAINING_STAGE_UNSCRAMBLED_ONES : V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200; |
| 572 | /* Be pessimistic and see what the handshake brings */ |
| 573 | s->negotiated_bit_rate = 1200; |
| 574 | break; |
| 575 | } |
| 576 | /* Once we have pulled in the symbol timing in a coarse way, use finer |
| 577 | steps to fine tune the timing. */ |
| 578 | if (s->rx.training_count == 30) |
| 579 | s->rx.gardner_step = 32; |
| 580 | break; |
| 581 | case V22BIS_RX_TRAINING_STAGE_UNSCRAMBLED_ONES: |
| 582 | /* Calling modem only */ |
| 583 | /* The calling modem should initially receive unscrambled ones at 1200bps */ |
| 584 | target = &v22bis_constellation[nearest]; |
| 585 | track_carrier(s, &z, target); |
| 586 | raw_bits = phase_steps[((nearest >> 2) - (s->rx.constellation_state >> 2)) & 3]; |
| 587 | s->rx.constellation_state = nearest; |
| 588 | if (raw_bits != s->rx.last_raw_bits) |
| 589 | s->rx.pattern_repeats = 0; |
| 590 | else |
| 591 | s->rx.pattern_repeats++; |
| 592 | if (++s->rx.training_count == ms_to_symbols(155 + 456)(((155 + 456)*600)/1000)) |
| 593 | { |
| 594 | /* After the first 155ms things should have been steady, so check if the last 456ms was |
| 595 | steady at 11 or 00. */ |
| 596 | if (raw_bits == s->rx.last_raw_bits |
| 597 | && |
| 598 | (raw_bits == 0x3 || raw_bits == 0x0) |
| 599 | && |
| 600 | s->rx.pattern_repeats >= ms_to_symbols(456)(((456)*600)/1000)) |
| 601 | { |
| 602 | /* It looks like the answering machine is sending us a clean unscrambled 11 or 00 */ |
| 603 | if (s->bit_rate == 2400) |
| 604 | { |
| 605 | /* Try to establish at 2400bps. */ |
| 606 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ starting U0011 (S1) (Caller)\n"); |
| 607 | s->tx.training = V22BIS_TX_TRAINING_STAGE_U0011; |
| 608 | s->tx.training_count = 0; |
| 609 | } |
| 610 | else |
| 611 | { |
| 612 | /* Only try to establish at 1200bps. */ |
| 613 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ starting S11 (1200) (Caller)\n"); |
| 614 | s->tx.training = V22BIS_TX_TRAINING_STAGE_S11; |
| 615 | s->tx.training_count = 0; |
| 616 | } |
| 617 | } |
| 618 | s->rx.pattern_repeats = 0; |
| 619 | s->rx.training_count = 0; |
| 620 | s->rx.training = V22BIS_RX_TRAINING_STAGE_UNSCRAMBLED_ONES_SUSTAINING; |
| 621 | } |
| 622 | break; |
| 623 | case V22BIS_RX_TRAINING_STAGE_UNSCRAMBLED_ONES_SUSTAINING: |
| 624 | /* Calling modem only */ |
| 625 | /* Wait for the end of the unscrambled ones at 1200bps. */ |
| 626 | target = &v22bis_constellation[nearest]; |
| 627 | track_carrier(s, &z, target); |
| 628 | raw_bits = phase_steps[((nearest >> 2) - (s->rx.constellation_state >> 2)) & 3]; |
| 629 | s->rx.constellation_state = nearest; |
| 630 | if (raw_bits != s->rx.last_raw_bits) |
| 631 | { |
| 632 | /* This looks like the end of the sustained initial unscrambled 11 or 00. */ |
| 633 | s->tx.training_count = 0; |
| 634 | s->tx.training = V22BIS_TX_TRAINING_STAGE_TIMED_S11; |
| 635 | s->rx.training_count = 0; |
| 636 | s->rx.training = V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200; |
| 637 | s->rx.pattern_repeats = 0; |
| 638 | } |
| 639 | break; |
| 640 | case V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200: |
| 641 | target = &v22bis_constellation[nearest]; |
| 642 | track_carrier(s, &z, target); |
| 643 | tune_equalizer(s, &z, target); |
| 644 | raw_bits = phase_steps[((nearest >> 2) - (s->rx.constellation_state >> 2)) & 3]; |
| 645 | bitstream = decode_baudx(s, nearest); |
Value stored to 'bitstream' is never read | |
| 646 | s->rx.training_count++; |
| 647 | //span_log(&s->logging, SPAN_LOG_FLOW, "S11 0x%02x 0x%02x 0x%X %d %d %d %d %d\n", raw_bits, nearest, bitstream, s->rx.scrambled_ones_to_date, 0, 0, 0, s->rx.training_count); |
| 648 | if (s->negotiated_bit_rate == 1200) |
| 649 | { |
| 650 | /* Search for the S1 signal */ |
| 651 | if ((s->rx.last_raw_bits ^ raw_bits) == 0x3) |
| 652 | { |
| 653 | s->rx.pattern_repeats++; |
| 654 | } |
| 655 | else |
| 656 | { |
| 657 | if (s->rx.pattern_repeats >= 15 && (s->rx.last_raw_bits == 0x3 || s->rx.last_raw_bits == 0x0)) |
| 658 | { |
| 659 | /* We should get a full run of 00 11 (about 60 bauds) at the calling modem, but only about 20 |
| 660 | at the answering modem, as the first 40 are TED settling time. */ |
| 661 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ S1 detected (%d long)\n", s->rx.pattern_repeats); |
| 662 | if (s->bit_rate == 2400) |
| 663 | { |
| 664 | if (!s->calling_party) |
| 665 | { |
| 666 | /* Accept establishment at 2400bps */ |
| 667 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ starting U0011 (S1) (Answerer)\n"); |
| 668 | s->tx.training = V22BIS_TX_TRAINING_STAGE_U0011; |
| 669 | s->tx.training_count = 0; |
| 670 | } |
| 671 | s->negotiated_bit_rate = 2400; |
| 672 | } |
| 673 | } |
| 674 | s->rx.pattern_repeats = 0; |
| 675 | } |
| 676 | if (s->rx.training_count >= ms_to_symbols(270)(((270)*600)/1000)) |
| 677 | { |
| 678 | /* If we haven't seen the S1 signal by now, we are committed to be in 1200bps mode. */ |
| 679 | if (s->calling_party) |
| 680 | { |
| 681 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ Rx normal operation (1200)\n"); |
| 682 | /* The transmit side needs to sustain the scrambled ones for a timed period. */ |
| 683 | s->tx.training_count = 0; |
| 684 | s->tx.training = V22BIS_TX_TRAINING_STAGE_TIMED_S11; |
| 685 | /* Normal reception starts immediately */ |
| 686 | s->rx.training = V22BIS_RX_TRAINING_STAGE_NORMAL_OPERATION; |
| 687 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 688 | s->rx.carrier_track_i = 8; |
| 689 | #else |
| 690 | s->rx.carrier_track_i = 8000.0f; |
| 691 | #endif |
| 692 | } |
| 693 | else |
| 694 | { |
| 695 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ starting S11 (1200) (Answerer)\n"); |
| 696 | /* The transmit side needs to sustain the scrambled ones for a timed period. */ |
| 697 | s->tx.training_count = 0; |
| 698 | s->tx.training = V22BIS_TX_TRAINING_STAGE_TIMED_S11; |
| 699 | /* The receive side needs to wait a timed period, receiving scrambled ones, |
| 700 | before entering normal operation. */ |
| 701 | s->rx.training = V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200_SUSTAINING; |
| 702 | } |
| 703 | } |
| 704 | } |
| 705 | else |
| 706 | { |
| 707 | if (s->calling_party) |
| 708 | { |
| 709 | if (s->rx.training_count >= ms_to_symbols(100 + 450)(((100 + 450)*600)/1000)) |
| 710 | { |
| 711 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ starting 16 way decisions (caller)\n"); |
| 712 | s->rx.sixteen_way_decisions = true1; |
| 713 | s->rx.training = V22BIS_RX_TRAINING_STAGE_WAIT_FOR_SCRAMBLED_ONES_AT_2400; |
| 714 | s->rx.pattern_repeats = 0; |
| 715 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 716 | s->rx.carrier_track_i = 8; |
| 717 | #else |
| 718 | s->rx.carrier_track_i = 8000.0f; |
| 719 | #endif |
| 720 | } |
| 721 | } |
| 722 | else |
| 723 | { |
| 724 | if (s->rx.training_count >= ms_to_symbols(450)(((450)*600)/1000)) |
| 725 | { |
| 726 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ starting 16 way decisions (answerer)\n"); |
| 727 | s->rx.sixteen_way_decisions = true1; |
| 728 | s->rx.training = V22BIS_RX_TRAINING_STAGE_WAIT_FOR_SCRAMBLED_ONES_AT_2400; |
| 729 | s->rx.pattern_repeats = 0; |
| 730 | } |
| 731 | } |
| 732 | } |
| 733 | break; |
| 734 | case V22BIS_RX_TRAINING_STAGE_SCRAMBLED_ONES_AT_1200_SUSTAINING: |
| 735 | target = &v22bis_constellation[nearest]; |
| 736 | track_carrier(s, &z, target); |
| 737 | tune_equalizer(s, &z, target); |
| 738 | bitstream = decode_baudx(s, nearest); |
| 739 | if (++s->rx.training_count > ms_to_symbols(270 + 765)(((270 + 765)*600)/1000)) |
| 740 | { |
| 741 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ Rx normal operation (1200)\n"); |
| 742 | s->rx.training = V22BIS_RX_TRAINING_STAGE_NORMAL_OPERATION; |
| 743 | } |
| 744 | break; |
| 745 | case V22BIS_RX_TRAINING_STAGE_WAIT_FOR_SCRAMBLED_ONES_AT_2400: |
| 746 | target = &v22bis_constellation[nearest]; |
| 747 | track_carrier(s, &z, target); |
| 748 | tune_equalizer(s, &z, target); |
| 749 | bitstream = decode_baudx(s, nearest); |
| 750 | /* We need 32 sustained 1's to switch into normal operation. */ |
| 751 | if (bitstream == 0xF) |
| 752 | { |
| 753 | if (++s->rx.pattern_repeats >= 9) |
| 754 | { |
| 755 | span_log(&s->logging, SPAN_LOG_FLOW, "+++ Rx normal operation (2400)\n"); |
| 756 | s->rx.training = V22BIS_RX_TRAINING_STAGE_NORMAL_OPERATION; |
| 757 | } |
| 758 | } |
| 759 | else |
| 760 | { |
| 761 | s->rx.pattern_repeats = 0; |
| 762 | } |
| 763 | break; |
| 764 | case V22BIS_RX_TRAINING_STAGE_PARKED: |
| 765 | default: |
| 766 | /* We failed to train! */ |
| 767 | /* Park here until the carrier drops. */ |
| 768 | target = &z; |
| 769 | break; |
| 770 | } |
| 771 | s->rx.last_raw_bits = raw_bits; |
| 772 | if (s->rx.qam_report) |
| 773 | s->rx.qam_report(s->rx.qam_user_data, &z, target, s->rx.constellation_state); |
| 774 | } |
| 775 | /*- End of function --------------------------------------------------------*/ |
| 776 | |
| 777 | SPAN_DECLARE_NONSTD(int)__attribute__((visibility("default"))) int v22bis_rx(v22bis_state_t *s, const int16_t amp[], int len) |
| 778 | { |
| 779 | int i; |
| 780 | int step; |
| 781 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 782 | complexi16_t z; |
| 783 | complexi16_t zz; |
| 784 | complexi16_t sample; |
| 785 | int32_t ii; |
| 786 | int32_t qq; |
| 787 | #else |
| 788 | complexf_t z; |
| 789 | complexf_t zz; |
| 790 | complexf_t sample; |
| 791 | float ii; |
| 792 | float qq; |
| 793 | #endif |
| 794 | int32_t root_power; |
| 795 | int32_t power; |
| 796 | |
| 797 | for (i = 0; i < len; i++) |
| 798 | { |
| 799 | /* Complex bandpass filter the signal, using a pair of FIRs, and RRC coeffs shifted |
| 800 | to centre at 1200Hz or 2400Hz. The filters support 12 fractional phase shifts, to |
| 801 | permit signal extraction very close to the middle of a symbol. */ |
| 802 | s->rx.rrc_filter[s->rx.rrc_filter_step] = amp[i]; |
| 803 | if (++s->rx.rrc_filter_step >= V22BIS_RX_FILTER_STEPS27) |
| 804 | s->rx.rrc_filter_step = 0; |
| 805 | |
| 806 | /* Calculate the I filter, with an arbitrary phase step, just so we can calculate |
| 807 | the signal power of the required carrier, with any guard tone or spillback of our |
| 808 | own transmitted signal suppressed. */ |
| 809 | if (s->calling_party) |
| 810 | { |
| 811 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 812 | ii = vec_circular_dot_prodi16(s->rx.rrc_filter, rx_pulseshaper_2400_re[6], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step) >> 15; |
| 813 | #else |
| 814 | ii = vec_circular_dot_prodf(s->rx.rrc_filter, rx_pulseshaper_2400_re[6], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step); |
| 815 | #endif |
| 816 | } |
| 817 | else |
| 818 | { |
| 819 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 820 | ii = vec_circular_dot_prodi16(s->rx.rrc_filter, rx_pulseshaper_1200_re[6], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step) >> 15; |
| 821 | #else |
| 822 | ii = vec_circular_dot_prodf(s->rx.rrc_filter, rx_pulseshaper_1200_re[6], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step); |
| 823 | #endif |
| 824 | } |
| 825 | power = power_meter_update(&s->rx.rx_power, (int16_t) ii); |
| 826 | if (s->rx.signal_present) |
| 827 | { |
| 828 | /* Look for power below the carrier off point */ |
| 829 | if (power < s->rx.carrier_off_power) |
| 830 | { |
| 831 | v22bis_restart(s, s->bit_rate); |
| 832 | v22bis_report_status_change(s, SIG_STATUS_CARRIER_DOWN); |
| 833 | continue; |
| 834 | } |
| 835 | } |
| 836 | else |
| 837 | { |
| 838 | /* Look for power exceeding the carrier on point */ |
| 839 | if (power < s->rx.carrier_on_power) |
| 840 | continue; |
| 841 | s->rx.signal_present = true1; |
| 842 | v22bis_report_status_change(s, SIG_STATUS_CARRIER_UP); |
| 843 | } |
| 844 | /* Only spend effort processing this data if the modem is not parked, after |
| 845 | a training failure. */ |
| 846 | if (s->rx.training == V22BIS_RX_TRAINING_STAGE_PARKED) |
| 847 | continue; |
| 848 | |
| 849 | /* Put things into the equalization buffer at T/2 rate. The Gardner algorithm |
| 850 | will fiddle the step to align this with the symbols. */ |
| 851 | if ((s->rx.eq_put_step -= PULSESHAPER_COEFF_SETS12) <= 0) |
| 852 | { |
| 853 | if (s->rx.training == V22BIS_RX_TRAINING_STAGE_SYMBOL_ACQUISITION) |
| 854 | { |
| 855 | /* Only AGC during the initial symbol acquisition, and then lock the gain. */ |
| 856 | if ((root_power = fixed_sqrt32(power)) == 0) |
| 857 | root_power = 1; |
| 858 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 859 | s->rx.agc_scaling = saturate16(((int32_t) (FP_SCALE(0.18f)(0.18f)*FP_SCALE(3.60f)(3.60f)))/root_power); |
| 860 | #else |
| 861 | s->rx.agc_scaling = FP_SCALE(0.18f)(0.18f)*FP_SCALE(3.60f)(3.60f)/root_power; |
| 862 | #endif |
| 863 | } |
| 864 | /* Pulse shape while still at the carrier frequency, using a quadrature |
| 865 | pair of filters. This results in a properly bandpass filtered complex |
| 866 | signal, which can be brought directly to bandband by complex mixing. |
| 867 | No further filtering, to remove mixer harmonics, is needed. */ |
| 868 | step = -s->rx.eq_put_step; |
| 869 | if (step > PULSESHAPER_COEFF_SETS12 - 1) |
| 870 | step = PULSESHAPER_COEFF_SETS12 - 1; |
| 871 | if (s->calling_party) |
| 872 | { |
| 873 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 874 | ii = vec_circular_dot_prodi16(s->rx.rrc_filter, rx_pulseshaper_2400_re[step], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step) >> 15; |
| 875 | qq = vec_circular_dot_prodi16(s->rx.rrc_filter, rx_pulseshaper_2400_im[step], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step) >> 15; |
| 876 | #else |
| 877 | ii = vec_circular_dot_prodf(s->rx.rrc_filter, rx_pulseshaper_2400_re[step], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step); |
| 878 | qq = vec_circular_dot_prodf(s->rx.rrc_filter, rx_pulseshaper_2400_im[step], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step); |
| 879 | #endif |
| 880 | } |
| 881 | else |
| 882 | { |
| 883 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 884 | ii = vec_circular_dot_prodi16(s->rx.rrc_filter, rx_pulseshaper_1200_re[step], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step) >> 15; |
| 885 | qq = vec_circular_dot_prodi16(s->rx.rrc_filter, rx_pulseshaper_1200_im[step], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step) >> 15; |
| 886 | #else |
| 887 | ii = vec_circular_dot_prodf(s->rx.rrc_filter, rx_pulseshaper_1200_re[step], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step); |
| 888 | qq = vec_circular_dot_prodf(s->rx.rrc_filter, rx_pulseshaper_1200_im[step], V22BIS_RX_FILTER_STEPS27, s->rx.rrc_filter_step); |
| 889 | #endif |
| 890 | } |
| 891 | /* Shift to baseband - since this is done in a full complex form, the |
| 892 | result is clean, and requires no further filtering apart from the |
| 893 | equalizer. */ |
| 894 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 895 | sample.re = (ii*s->rx.agc_scaling) >> FP_SHIFT_FACTOR; |
| 896 | sample.im = (qq*s->rx.agc_scaling) >> FP_SHIFT_FACTOR; |
| 897 | z = dds_lookup_complexi16(s->rx.carrier_phase); |
| 898 | zz.re = ((int32_t) sample.re*z.re - (int32_t) sample.im*z.im) >> 15; |
| 899 | zz.im = ((int32_t) -sample.re*z.im - (int32_t) sample.im*z.re) >> 15; |
| 900 | #else |
| 901 | sample.re = ii*s->rx.agc_scaling; |
| 902 | sample.im = qq*s->rx.agc_scaling; |
| 903 | z = dds_lookup_complexf(s->rx.carrier_phase); |
| 904 | zz.re = sample.re*z.re - sample.im*z.im; |
| 905 | zz.im = -sample.re*z.im - sample.im*z.re; |
| 906 | #endif |
| 907 | s->rx.eq_put_step += PULSESHAPER_COEFF_SETS12*40/(3*2); |
| 908 | process_half_baud(s, &zz); |
| 909 | } |
| 910 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 911 | dds_advance(&s->rx.carrier_phase, s->rx.carrier_phase_rate); |
| 912 | #else |
| 913 | dds_advancef(&s->rx.carrier_phase, s->rx.carrier_phase_rate); |
| 914 | #endif |
| 915 | } |
| 916 | return 0; |
| 917 | } |
| 918 | /*- End of function --------------------------------------------------------*/ |
| 919 | |
| 920 | SPAN_DECLARE_NONSTD(int)__attribute__((visibility("default"))) int v22bis_rx_fillin(v22bis_state_t *s, int len) |
| 921 | { |
| 922 | int i; |
| 923 | |
| 924 | /* We want to sustain the current state (i.e carrier on<->carrier off), and |
| 925 | try to sustain the carrier phase. We should probably push the filters, as well */ |
| 926 | span_log(&s->logging, SPAN_LOG_FLOW, "Fill-in %d samples\n", len); |
| 927 | if (!s->rx.signal_present) |
| 928 | return 0; |
| 929 | for (i = 0; i < len; i++) |
| 930 | { |
| 931 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 932 | dds_advance(&s->rx.carrier_phase, s->rx.carrier_phase_rate); |
| 933 | #else |
| 934 | dds_advancef(&s->rx.carrier_phase, s->rx.carrier_phase_rate); |
| 935 | #endif |
| 936 | } |
| 937 | /* TODO: Advance the symbol phase the appropriate amount */ |
| 938 | return 0; |
| 939 | } |
| 940 | /*- End of function --------------------------------------------------------*/ |
| 941 | |
| 942 | int v22bis_rx_restart(v22bis_state_t *s) |
| 943 | { |
| 944 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 945 | vec_zeroi16(s->rx.rrc_filter, sizeof(s->rx.rrc_filter)/sizeof(s->rx.rrc_filter[0])); |
| 946 | s->rx.training_error = 0; |
| 947 | #else |
| 948 | vec_zerof(s->rx.rrc_filter, sizeof(s->rx.rrc_filter)/sizeof(s->rx.rrc_filter[0])); |
| 949 | s->rx.training_error = 0.0f; |
| 950 | #endif |
| 951 | s->rx.rrc_filter_step = 0; |
| 952 | s->rx.scramble_reg = 0; |
| 953 | s->rx.scrambler_pattern_count = 0; |
| 954 | s->rx.training = V22BIS_RX_TRAINING_STAGE_SYMBOL_ACQUISITION; |
| 955 | s->rx.training_count = 0; |
| 956 | s->rx.signal_present = false0; |
| 957 | |
| 958 | s->rx.carrier_phase_rate = (s->calling_party) ? DDS_PHASE_RATE(2400.0f)(int32_t) ((2400.0f)*65536.0f*65536.0f/8000) : DDS_PHASE_RATE(1200.0f)(int32_t) ((1200.0f)*65536.0f*65536.0f/8000); |
| 959 | s->rx.carrier_phase = 0; |
| 960 | power_meter_init(&s->rx.rx_power, 5); |
| 961 | v22bis_rx_signal_cutoff(s, -45.5f); |
| 962 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 963 | s->rx.agc_scaling = (float) (1024.0f*1024.0f)*0.0005f*0.025f; |
| 964 | #else |
| 965 | s->rx.agc_scaling = 0.0005f*0.025f; |
| 966 | #endif |
| 967 | |
| 968 | s->rx.constellation_state = 0; |
| 969 | s->rx.sixteen_way_decisions = false0; |
| 970 | |
| 971 | equalizer_reset(s); |
| 972 | |
| 973 | s->rx.pattern_repeats = 0; |
| 974 | s->rx.last_raw_bits = 0; |
| 975 | s->rx.gardner_integrate = 0; |
| 976 | s->rx.gardner_step = 256; |
| 977 | s->rx.baud_phase = 0; |
| 978 | s->rx.total_baud_timing_correction = 0; |
| 979 | /* We want the carrier to pull in faster on the answerer side, as it has very little time to adapt. */ |
| 980 | #if defined(SPANDSP_USE_FIXED_POINT) |
| 981 | s->rx.carrier_track_i = (s->calling_party) ? 8 : 40; |
| 982 | s->rx.carrier_track_p = 8000; |
| 983 | #else |
| 984 | s->rx.carrier_track_i = (s->calling_party) ? 8000.0f : 40000.0f; |
| 985 | s->rx.carrier_track_p = 8000000.0f; |
| 986 | #endif |
| 987 | |
| 988 | s->negotiated_bit_rate = 1200; |
| 989 | |
| 990 | return 0; |
| 991 | } |
| 992 | /*- End of function --------------------------------------------------------*/ |
| 993 | |
| 994 | SPAN_DECLARE(void)__attribute__((visibility("default"))) void v22bis_rx_set_qam_report_handler(v22bis_state_t *s, qam_report_handler_t handler, void *user_data) |
| 995 | { |
| 996 | s->rx.qam_report = handler; |
| 997 | s->rx.qam_user_data = user_data; |
| 998 | } |
| 999 | /*- End of function --------------------------------------------------------*/ |
| 1000 | /*- End of file ------------------------------------------------------------*/ |