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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 | /*****************************************************************************/ /* * sm_afsk2400_7.c -- soundcard radio modem driver, 2400 baud AFSK modem * * Copyright (C) 1996 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. * */ /* * This driver is intended to be compatible with TCM3105 modems * overclocked to 7.3728MHz. The mark and space frequencies therefore * lie at 3658 and 1996 Hz. * Note that I do _not_ recommend the building of such links, I provide * this only for the users who live in the coverage area of such * a "legacy" link. */ #include "sm.h" #include "sm_tbl_afsk2400_7.h" /* --------------------------------------------------------------------- */ struct demod_state_afsk24 { unsigned int shreg; unsigned int bit_pll; unsigned char last_sample; unsigned int dcd_shreg; int dcd_sum0, dcd_sum1, dcd_sum2; unsigned int dcd_time; unsigned char last_rxbit; }; struct mod_state_afsk24 { unsigned int shreg; unsigned char tx_bit; unsigned int bit_pll; unsigned int tx_seq; unsigned int phinc; }; /* --------------------------------------------------------------------- */ static const int dds_inc[2] = { AFSK24_TX_FREQ_LO*0x10000/AFSK24_SAMPLERATE, AFSK24_TX_FREQ_HI*0x10000/AFSK24_SAMPLERATE }; static void modulator_2400_u8(struct sm_state *sm, unsigned char *buf, unsigned int buflen) { struct mod_state_afsk24 *st = (struct mod_state_afsk24 *)(&sm->m); for (; buflen > 0; buflen--, buf++) { if (st->tx_seq < 0x5555) { if (st->shreg <= 1) st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000; st->tx_bit = (st->tx_bit ^ (!(st->shreg & 1))) & 1; st->shreg >>= 1; st->phinc = dds_inc[st->tx_bit & 1]; } st->tx_seq += 0x5555; st->tx_seq &= 0xffff; *buf = OFFSCOS(st->bit_pll); st->bit_pll += st->phinc; } } /* --------------------------------------------------------------------- */ static void modulator_2400_s16(struct sm_state *sm, short *buf, unsigned int buflen) { struct mod_state_afsk24 *st = (struct mod_state_afsk24 *)(&sm->m); for (; buflen > 0; buflen--, buf++) { if (st->tx_seq < 0x5555) { if (st->shreg <= 1) st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000; st->tx_bit = (st->tx_bit ^ (!(st->shreg & 1))) & 1; st->shreg >>= 1; st->phinc = dds_inc[st->tx_bit & 1]; } st->tx_seq += 0x5555; st->tx_seq &= 0xffff; *buf = COS(st->bit_pll); st->bit_pll += st->phinc; } } /* --------------------------------------------------------------------- */ extern __inline__ int convolution14_u8(const unsigned char *st, const int *coeff, int csum) { int sum = -0x80 * csum; sum += (st[0] * coeff[0]); sum += (st[-1] * coeff[1]); sum += (st[-2] * coeff[2]); sum += (st[-3] * coeff[3]); sum += (st[-4] * coeff[4]); sum += (st[-5] * coeff[5]); sum += (st[-6] * coeff[6]); sum += (st[-7] * coeff[7]); sum += (st[-8] * coeff[8]); sum += (st[-9] * coeff[9]); sum += (st[-10] * coeff[10]); sum += (st[-11] * coeff[11]); sum += (st[-12] * coeff[12]); sum += (st[-13] * coeff[13]); sum >>= 7; return sum * sum; } extern __inline__ int convolution14_s16(const short *st, const int *coeff, int csum) { int sum = 0; sum += (st[0] * coeff[0]); sum += (st[-1] * coeff[1]); sum += (st[-2] * coeff[2]); sum += (st[-3] * coeff[3]); sum += (st[-4] * coeff[4]); sum += (st[-5] * coeff[5]); sum += (st[-6] * coeff[6]); sum += (st[-7] * coeff[7]); sum += (st[-8] * coeff[8]); sum += (st[-9] * coeff[9]); sum += (st[-10] * coeff[10]); sum += (st[-11] * coeff[11]); sum += (st[-12] * coeff[12]); sum += (st[-13] * coeff[13]); sum >>= 15; return sum * sum; } extern __inline__ int do_filter_2400_u8(const unsigned char *buf) { int sum = convolution14_u8(buf, afsk24_tx_lo_i, SUM_AFSK24_TX_LO_I); sum += convolution14_u8(buf, afsk24_tx_lo_q, SUM_AFSK24_TX_LO_Q); sum -= convolution14_u8(buf, afsk24_tx_hi_i, SUM_AFSK24_TX_HI_I); sum -= convolution14_u8(buf, afsk24_tx_hi_q, SUM_AFSK24_TX_HI_Q); return sum; } extern __inline__ int do_filter_2400_s16(const short *buf) { int sum = convolution14_s16(buf, afsk24_tx_lo_i, SUM_AFSK24_TX_LO_I); sum += convolution14_s16(buf, afsk24_tx_lo_q, SUM_AFSK24_TX_LO_Q); sum -= convolution14_s16(buf, afsk24_tx_hi_i, SUM_AFSK24_TX_HI_I); sum -= convolution14_s16(buf, afsk24_tx_hi_q, SUM_AFSK24_TX_HI_Q); return sum; } /* --------------------------------------------------------------------- */ static void demodulator_2400_u8(struct sm_state *sm, const unsigned char *buf, unsigned int buflen) { struct demod_state_afsk24 *st = (struct demod_state_afsk24 *)(&sm->d); int j; int sum; unsigned char newsample; for (; buflen > 0; buflen--, buf++) { sum = do_filter_2400_u8(buf); st->dcd_shreg <<= 1; st->bit_pll += AFSK24_BITPLL_INC; newsample = (sum > 0); if (st->last_sample ^ newsample) { st->last_sample = newsample; st->dcd_shreg |= 1; if (st->bit_pll < (0x8000+AFSK24_BITPLL_INC/2)) st->bit_pll += AFSK24_BITPLL_INC/2; else st->bit_pll -= AFSK24_BITPLL_INC/2; j = /* 2 * */ hweight8(st->dcd_shreg & 0x1c) - hweight16(st->dcd_shreg & 0x1e0); st->dcd_sum0 += j; } 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 = 120; } if (st->bit_pll >= 0x10000) { st->bit_pll &= 0xffff; st->shreg >>= 1; st->shreg |= (!(st->last_rxbit ^ st->last_sample)) << 16; st->last_rxbit = st->last_sample; diag_trigger(sm); if (st->shreg & 1) { hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1); st->shreg = 0x10000; } } diag_add(sm, (((int)*buf)-0x80) << 8, sum); } } /* --------------------------------------------------------------------- */ static void demodulator_2400_s16(struct sm_state *sm, const short *buf, unsigned int buflen) { struct demod_state_afsk24 *st = (struct demod_state_afsk24 *)(&sm->d); int j; int sum; unsigned char newsample; for (; buflen > 0; buflen--, buf++) { sum = do_filter_2400_s16(buf); st->dcd_shreg <<= 1; st->bit_pll += AFSK24_BITPLL_INC; newsample = (sum > 0); if (st->last_sample ^ newsample) { st->last_sample = newsample; st->dcd_shreg |= 1; if (st->bit_pll < (0x8000+AFSK24_BITPLL_INC/2)) st->bit_pll += AFSK24_BITPLL_INC/2; else st->bit_pll -= AFSK24_BITPLL_INC/2; j = /* 2 * */ hweight8(st->dcd_shreg & 0x1c) - hweight16(st->dcd_shreg & 0x1e0); st->dcd_sum0 += j; } 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 = 120; } if (st->bit_pll >= 0x10000) { st->bit_pll &= 0xffff; st->shreg >>= 1; st->shreg |= (!(st->last_rxbit ^ st->last_sample)) << 16; st->last_rxbit = st->last_sample; diag_trigger(sm); if (st->shreg & 1) { hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1); st->shreg = 0x10000; } } diag_add(sm, *buf, sum); } } /* --------------------------------------------------------------------- */ static void demod_init_2400(struct sm_state *sm) { struct demod_state_afsk24 *st = (struct demod_state_afsk24 *)(&sm->d); st->dcd_time = 120; st->dcd_sum0 = 2; } /* --------------------------------------------------------------------- */ const struct modem_tx_info sm_afsk2400_7_tx = { "afsk2400_7", sizeof(struct mod_state_afsk24), AFSK24_SAMPLERATE, 2400, modulator_2400_u8, modulator_2400_s16, NULL }; const struct modem_rx_info sm_afsk2400_7_rx = { "afsk2400_7", sizeof(struct demod_state_afsk24), AFSK24_SAMPLERATE, 2400, 14, AFSK24_SAMPLERATE/2400, demodulator_2400_u8, demodulator_2400_s16, demod_init_2400 }; /* --------------------------------------------------------------------- */ |