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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 | /*****************************************************************************/ /* * sm_psk4800.c -- soundcard radio modem driver, 4800 baud 8PSK modem * * Copyright (C) 1997 Thomas Sailer (sailer@ife.ee.ethz.ch) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * Please note that the GPL allows you to use the driver, NOT the radio. * In order to use the radio, you need a license from the communications * authority of your country. * */ #include "sm.h" #include "sm_tbl_psk4800.h" /* --------------------------------------------------------------------- */ #define DESCRAM_TAP1 0x20000 #define DESCRAM_TAP2 0x01000 #define DESCRAM_TAP3 0x00001 #define DESCRAM_TAPSH1 17 #define DESCRAM_TAPSH2 12 #define DESCRAM_TAPSH3 0 #define SCRAM_TAP1 0x20000 /* X^17 */ #define SCRAM_TAPN 0x00021 /* X^0+X^5 */ #define SCRAM_SHIFT 17 /* --------------------------------------------------------------------- */ struct demod_state_psk48 { /* * input mixer and lowpass */ short infi[PSK48_RXF_LEN/2], infq[PSK48_RXF_LEN/2]; unsigned int downmixer; int ovrphase; short magi, magq; /* * sampling instant recovery */ int pwrhist[5]; unsigned int s_phase; int cur_sync; /* * phase recovery */ short cur_phase_dev; short last_ph_err; unsigned short pskph; unsigned int phase; unsigned short last_pskph; unsigned char cur_raw, last_raw, rawbits; /* * decoding */ unsigned int shreg; unsigned long descram; unsigned int bit_pll; unsigned char last_sample; unsigned int dcd_shreg; int dcd_sum0, dcd_sum1, dcd_sum2; unsigned int dcd_time; }; struct mod_state_psk48 { unsigned char txbits[PSK48_TXF_NUMSAMPLES]; unsigned short txphase; unsigned int shreg; unsigned long scram; const short *tbl; unsigned int txseq; }; /* --------------------------------------------------------------------- */ static void modulator_4800_u8(struct sm_state *sm, unsigned char *buf, unsigned int buflen) { struct mod_state_psk48 *st = (struct mod_state_psk48 *)(&sm->m); int i, j; int si, sq; for (; buflen > 0; buflen--, buf++) { if (!st->txseq++) { memmove(st->txbits+1, st->txbits, sizeof(st->txbits)-sizeof(st->txbits[0])); for (i = 0; i < 3; i++) { if (st->shreg <= 1) st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000; st->scram = (st->scram << 1) | (st->shreg & 1); st->shreg >>= 1; if (st->scram & SCRAM_TAP1) st->scram ^= SCRAM_TAPN; } j = (st->scram >> (SCRAM_SHIFT+3)) & 7; st->txbits[0] -= (j ^ (j >> 1)); st->txbits[0] &= 7; st->tbl = psk48_tx_table; } if (st->txseq >= PSK48_TXF_OVERSAMPLING) st->txseq = 0; for (j = si = sq = 0; j < PSK48_TXF_NUMSAMPLES; j++, st->tbl += 16) { si += st->tbl[st->txbits[j]]; sq += st->tbl[st->txbits[j]+8]; } *buf = ((si*COS(st->txphase)+ sq*SIN(st->txphase)) >> 23) + 0x80; st->txphase = (st->txphase + PSK48_PHASEINC) & 0xffffu; } } /* --------------------------------------------------------------------- */ static void modulator_4800_s16(struct sm_state *sm, short *buf, unsigned int buflen) { struct mod_state_psk48 *st = (struct mod_state_psk48 *)(&sm->m); int i, j; int si, sq; for (; buflen > 0; buflen--, buf++) { if (!st->txseq++) { memmove(st->txbits+1, st->txbits, sizeof(st->txbits)-sizeof(st->txbits[0])); for (i = 0; i < 3; i++) { if (st->shreg <= 1) st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000; st->scram = (st->scram << 1) | (st->shreg & 1); st->shreg >>= 1; if (st->scram & SCRAM_TAP1) st->scram ^= SCRAM_TAPN; } j = (st->scram >> (SCRAM_SHIFT+3)) & 7; st->txbits[0] -= (j ^ (j >> 1)); st->txbits[0] &= 7; st->tbl = psk48_tx_table; } if (st->txseq >= PSK48_TXF_OVERSAMPLING) st->txseq = 0; for (j = si = sq = 0; j < PSK48_TXF_NUMSAMPLES; j++, st->tbl += 16) { si += st->tbl[st->txbits[j]]; sq += st->tbl[st->txbits[j]+8]; } *buf = (si*COS(st->txphase)+ sq*SIN(st->txphase)) >> 15; st->txphase = (st->txphase + PSK48_PHASEINC) & 0xffffu; } } /* --------------------------------------------------------------------- */ static __inline__ unsigned short tbl_atan(short q, short i) { short tmp; unsigned short argoffs = 0; if (i == 0 && q == 0) return 0; switch (((q < 0) << 1) | (i < 0)) { case 0: break; case 1: tmp = q; q = -i; i = tmp; argoffs = 0x4000; break; case 3: q = -q; i = -i; argoffs = 0x8000; break; case 2: tmp = -q; q = i; i = tmp; argoffs = 0xc000; break; } if (q > i) { tmp = i / q * ATAN_TABLEN; return (argoffs+0x4000-atan_tab[((i<<15)/q*ATAN_TABLEN>>15)]) &0xffffu; } return (argoffs+atan_tab[((q<<15)/i*ATAN_TABLEN)>>15])&0xffffu; } #define ATAN(q,i) tbl_atan(q, i) /* --------------------------------------------------------------------- */ static void demod_psk48_baseband(struct sm_state *sm, struct demod_state_psk48 *st, short vali, short valq) { int i, j; st->magi = vali; st->magq = valq; memmove(st->pwrhist+1, st->pwrhist, sizeof(st->pwrhist)-sizeof(st->pwrhist[0])); st->pwrhist[0] = st->magi * st->magi + st->magq * st->magq; st->cur_sync = ((st->pwrhist[4] >> 2) > st->pwrhist[2] && (st->pwrhist[0] >> 2) > st->pwrhist[2] && st-> pwrhist[3] > st->pwrhist[2] && st->pwrhist[1] > st->pwrhist[2]); st->s_phase &= 0xffff; st->s_phase += PSK48_SPHASEINC; st->dcd_shreg <<= 1; if (st->cur_sync) { if (st->s_phase >= (0x8000 + 5*PSK48_SPHASEINC/2)) st->s_phase -= PSK48_SPHASEINC/6; else st->s_phase += PSK48_SPHASEINC/6; st->dcd_sum0 = 4*hweight8(st->dcd_shreg & 0xf8)- hweight16(st->dcd_shreg & 0x1f00); } if ((--st->dcd_time) <= 0) { hdlcdrv_setdcd(&sm->hdrv, (st->dcd_sum0 + st->dcd_sum1 + st->dcd_sum2) < 0); st->dcd_sum2 = st->dcd_sum1; st->dcd_sum1 = st->dcd_sum0; st->dcd_sum0 = 2; /* slight bias */ st->dcd_time = 240; } if (st->s_phase < 0x10000) return; /* * sample one constellation */ st->last_pskph = st->pskph; st->pskph = (ATAN(st->magq, st->magi)- st->phase) & 0xffffu; st->last_ph_err = (st->pskph & 0x1fffu) - 0x1000; st->phase += st->last_ph_err/16; st->last_raw = st->cur_raw; st->cur_raw = ((st->pskph >> 13) & 7); i = (st->cur_raw - st->last_raw) & 7; st->rawbits = i ^ (i >> 1) ^ (i >> 2); st->descram = (st->descram << 3) | (st->rawbits); hdlcdrv_channelbit(&sm->hdrv, st->descram & 4); hdlcdrv_channelbit(&sm->hdrv, st->descram & 2); hdlcdrv_channelbit(&sm->hdrv, st->descram & 1); i = (((st->descram >> DESCRAM_TAPSH1) & 7) ^ ((st->descram >> DESCRAM_TAPSH2) & 7) ^ ((st->descram >> DESCRAM_TAPSH3) & 7)); for (j = 4; j; j >>= 1) { st->shreg >>= 1; st->shreg |= (!!(i & j)) << 16; if (st->shreg & 1) { hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1); st->shreg = 0x10000; } } #if 0 st->dcd_shreg <<= 1; st->bit_pll += 0x4000; curbit = (*buf >= 0x80); if (st->last_sample ^ curbit) { st->dcd_shreg |= 1; st->bit_pll += pll_corr [st->bit_pll < 0xa000]; st->dcd_sum0 += 8 * hweight8(st->dcd_shreg & 0x0c) - !!(st->dcd_shreg & 0x10); } st->last_sample = curbit; hdlcdrv_channelbit(&sm->hdrv, st->last_sample); if ((--st->dcd_time) <= 0) { hdlcdrv_setdcd(&sm->hdrv, (st->dcd_sum0 + st->dcd_sum1 + st->dcd_sum2) < 0); st->dcd_sum2 = st->dcd_sum1; st->dcd_sum1 = st->dcd_sum0; st->dcd_sum0 = 2; /* slight bias */ st->dcd_time = 240; } if (st->bit_pll >= 0x10000) { st->bit_pll &= 0xffffu; st->descram = (st->descram << 1) | curbit; descx = st->descram ^ (st->descram >> 1); descx ^= ((descx >> DESCRAM_TAPSH1) ^ (descx >> DESCRAM_TAPSH2)); st->shreg >>= 1; st->shreg |= (!(descx & 1)) << 16; if (st->shreg & 1) { hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1); st->shreg = 0x10000; } diag_trigger(sm); } diag_add_one(sm, ((short)(*buf - 0x80)) << 8); #endif diag_trigger(sm); diag_add_constellation(sm, (vali*COS(st->phase)+ valq*SIN(st->phase)) >> 13, (valq*COS(st->phase) - vali*SIN(st->phase)) >> 13); } /* --------------------------------------------------------------------- */ static void demodulator_4800_u8(struct sm_state *sm, const unsigned char *buf, unsigned int buflen) { struct demod_state_psk48 *st = (struct demod_state_psk48 *)(&sm->d); int i, si, sq; const short *coeff; for (; buflen > 0; buflen--, buf++) { memmove(st->infi+1, st->infi, sizeof(st->infi)-sizeof(st->infi[0])); memmove(st->infq+1, st->infq, sizeof(st->infq)-sizeof(st->infq[0])); si = *buf; si &= 0xff; si -= 128; diag_add_one(sm, si << 8); st->infi[0] = (si * COS(st->downmixer))>>7; st->infq[0] = (si * SIN(st->downmixer))>>7; st->downmixer = (st->downmixer-PSK48_PHASEINC)&0xffffu; for (i = si = sq = 0, coeff = psk48_rx_coeff; i < (PSK48_RXF_LEN/2); i++, coeff += 2) { si += st->infi[i] * (*coeff); sq += st->infq[i] * (*coeff); } demod_psk48_baseband(sm, st, si >> 15, sq >> 15); for (i = si = sq = 0, coeff = psk48_rx_coeff + 1; i < (PSK48_RXF_LEN/2); i++, coeff += 2) { si += st->infi[i] * (*coeff); sq += st->infq[i] * (*coeff); } demod_psk48_baseband(sm, st, si >> 15, sq >> 15); } } /* --------------------------------------------------------------------- */ static void demodulator_4800_s16(struct sm_state *sm, const short *buf, unsigned int buflen) { struct demod_state_psk48 *st = (struct demod_state_psk48 *)(&sm->d); int i, si, sq; const short *coeff; for (; buflen > 0; buflen--, buf++) { memmove(st->infi+1, st->infi, sizeof(st->infi)-sizeof(st->infi[0])); memmove(st->infq+1, st->infq, sizeof(st->infq)-sizeof(st->infq[0])); si = *buf; diag_add_one(sm, si); st->infi[0] = (si * COS(st->downmixer))>>15; st->infq[0] = (si * SIN(st->downmixer))>>15; st->downmixer = (st->downmixer-PSK48_PHASEINC)&0xffffu; for (i = si = sq = 0, coeff = psk48_rx_coeff; i < (PSK48_RXF_LEN/2); i++, coeff += 2) { si += st->infi[i] * (*coeff); sq += st->infq[i] * (*coeff); } demod_psk48_baseband(sm, st, si >> 15, sq >> 15); for (i = si = sq = 0, coeff = psk48_rx_coeff + 1; i < (PSK48_RXF_LEN/2); i++, coeff += 2) { si += st->infi[i] * (*coeff); sq += st->infq[i] * (*coeff); } demod_psk48_baseband(sm, st, si >> 15, sq >> 15); } } /* --------------------------------------------------------------------- */ static void mod_init_4800(struct sm_state *sm) { struct mod_state_psk48 *st = (struct mod_state_psk48 *)(&sm->m); st->scram = 1; } /* --------------------------------------------------------------------- */ static void demod_init_4800(struct sm_state *sm) { struct demod_state_psk48 *st = (struct demod_state_psk48 *)(&sm->d); st->dcd_time = 120; st->dcd_sum0 = 2; } /* --------------------------------------------------------------------- */ const struct modem_tx_info sm_psk4800_tx = { "psk4800", sizeof(struct mod_state_psk48), PSK48_SAMPLERATE, 4800, modulator_4800_u8, modulator_4800_s16, mod_init_4800 }; const struct modem_rx_info sm_psk4800_rx = { "psk4800", sizeof(struct demod_state_psk48), PSK48_SAMPLERATE, 4800, 1, PSK48_TXF_OVERSAMPLING, demodulator_4800_u8, demodulator_4800_s16, demod_init_4800 }; /* --------------------------------------------------------------------- */ |