Микроконтроллеры

Декодер Витерби для твоего кода, знает твои полиномы уже: http://www.pudn.com/downloads53/sourcecode/math/detail183689.html
/* Viterbi decoder for arbitrary convolutional code * viterbi27 and viterbi37 for the r=1/2 and r=1/3 K=7 codes are faster * Copyright 1999 Phil Karn, KA9Q * May be used under the terms of the GNU Public License */ /* Select code here */ #define K 15 /* Constraint length */ #define N 6 /* Number of symbols per data bit */ #define Polys Poly615 /* Select polynomials here */ /* Rate 1/2 codes */ unsigned int Poly23[] = { 0x7, 0x5 }; /* K=3 */ unsigned int Poly24[] = { 0xf, 0xb }; /* k=4 */ unsigned int Poly25[] = { 0x17, 0x19 }; /* k=5 */ unsigned int Poly25a[] = { 0x13, 0x1b }; /* k=5, used in GSM? */ unsigned int Poly26[] = { 0x2f, 0x35 }; /* k=6 */ unsigned int Poly27[] = { 0x6d, 0x4f }; /* k=7; very popular with NASA and industry */ unsigned int Poly28[] = { 0x9f, 0xe5 }; /* k=8 */ unsigned int Poly29[] = { 0x1af, 0x11d }; /* k=9; used in IS-95 CDMA */ unsigned int Poly215[] = { 0x45dd, 0x69e3 }; /* k = 15 */ /* Rate 1/3 codes */ unsigned int Poly33[] = { 0x7, 0x7, 0x5 }; /* k = 3 */ unsigned int Poly34[] = { 0xf, 0xb, 0xd }; /* k = 4 */ unsigned int Poly35[] = { 0x1f, 0x1b, 0x15 }; /* k = 5 */ unsigned int Poly36[] = { 0x2f, 0x35, 0x39 }; /* k = 6 */ unsigned int Poly37[] = { 0x4f, 0x57, 0x6d }; /* k = 7; also popular with NASA and industry */ unsigned int Poly38[] = { 0xef, 0x9b, 0xa9 }; /* k = 8 */ unsigned int Poly39[] = { 0x1ed, 0x19b, 0x127 }; /* k = 9; used in IS-95 CDMA */ /* Rate 1/6 code */ unsigned int Poly615[] = { 042631, 047245, 073363, 056507, 077267, 064537 }; /* k=15 on Mars Pathfinder */ #if (K>=6) #define D (1 << (K-6)) #else #define D 1 #endif #include <memory.h> #define NULL ((void *)0) extern unsigned char Partab[]; /* Parity lookup table */ int Rate = N; int Syms[1 << K]; int VDInit; inline int parity(int x) { x ^= (x >> 16); x ^= (x >> 8); return Partab[x & 0xff]; } /* Convolutionally encode data into binary symbols */ encode( unsigned char *symbols, unsigned char *data, unsigned int nbytes, unsigned int startstate, unsigned int endstate) { int i,j; unsigned int encstate = startstate; while(nbytes-- != 0){ for(i=7;i>=0;i--){ encstate = (encstate << 1) | ((*data >> i) & 1); for(j=0;j<N;j++) *symbols++ = parity(encstate & Polys[j]); } data++; } /* Flush out tail */ for(i=K-2;i>=0;i--){ encstate = (encstate << 1) | ((endstate >> i) & 1); for(j=0;j<N;j++) *symbols++ = parity(encstate & Polys[j]); } return 0; } /* Viterbi decoder */ int viterbi( unsigned long *metric, /* Final path metric (returned value) */ unsigned char *data, /* Decoded output data */ unsigned char *symbols, /* Raw deinterleaved input symbols */ unsigned int nbits, /* Number of output bits */ int mettab[2][256], /* Metric table, [sent sym][rx symbol] */ unsigned int startstate, /* Encoder starting state */ unsigned int endstate /* Encoder ending state */ ){ int bitcnt = -(K-1); long m0,m1; int i,j,sym; int mets[1 << N]; unsigned long paths[(nbits+K-1)*D],*pp,mask; long cmetric[1 << (K-1)],nmetric[1 << (K-1)]; memset(paths,0,sizeof(paths)); if(!VDInit){ for(i=0;i<(1<<K);i++){ sym = 0; for(j=0;j<N;j++) sym = (sym << 1) + parity(i & Polys[j]); Syms[i] = sym; } VDInit++; } startstate &= ~((1<<(K-1)) - 1); endstate &= ~((1<<(K-1)) - 1); /* Initialize starting metrics */ for(i=0;i< 1<<(K-1);i++) cmetric[i] = -999999; cmetric[startstate] = 0; pp = paths; for(;;){ /* For each data bit */ /* Read input symbols and compute branch metrics */ for(i=0;i< 1<<N;i++){ mets[i] = 0; for(j=0;j<N;j++){ mets[i] += mettab[(i >> (N-j-1)) & 1][symbols[j]]; } } symbols += N; /* Run the add-compare-select operations */ mask = 1; for(i=0;i< 1 << (K-1);i+=2){ int b1,b2; b1 = mets[Syms[i]]; nmetric[i] = m0 = cmetric[i/2] + b1; b2 = mets[Syms[i+1]]; b1 -= b2; m1 = cmetric[(i/2) + (1<<(K-2))] + b2; if(m1 > m0){ nmetric[i] = m1; *pp |= mask; } m0 -= b1; nmetric[i+1] = m0; m1 += b1; if(m1 > m0){ nmetric[i+1] = m1; *pp |= mask << 1; } mask <<= 2; if(mask == 0){ mask = 1; pp++; } } if(mask != 1){ pp++; } if(++bitcnt == nbits){ *metric = nmetric[endstate]; break; } memcpy(cmetric,nmetric,sizeof(cmetric)); } /* Chain back from terminal state to produce decoded data */ if(data == NULL) return 0;/* Discard output */ memset(data,0,(nbits+7)/8); /* round up in case nbits % 8 != 0 */ for(i=nbits-1;i >= 0;i--){ pp -= D; if(pp[endstate >> 5] & (1 << (endstate & 31))){ endstate |= (1 << (K-1)); data[i>>3] |= 0x80 >> (i&7); } endstate >>= 1; } return 0; }