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Install ftrsd decoder in place of kvasd. 

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/map65@6399 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Joe Taylor 2016-01-13 20:38:28 +00:00
parent 4a25cd607c
commit faed5be460
11 changed files with 607 additions and 342 deletions
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2
libm65/CMakeLists.txt
View File

@ -71,6 +71,7 @@ set (FSRCS
ftnquit.f90
gen65.f90
getdphi.f90
graycode65.f90
iqcal.f90
iqfix.f90
jt65code.f90
@ -138,6 +139,7 @@ set (FSRCS
set (CSRCS
decode_rs.c
encode_rs.c
ftrsd2.c
gran.c
igray.c
init_rs.c

459
libm65/decode_rs.c
View File

@ -1,6 +1,7 @@
/* Reed-Solomon decoder
* Copyright 2002 Phil Karn, KA9Q
* May be used under the terms of the GNU General Public License (GPL)
* Modified by Steve Franke, K9AN, for use in a soft-symbol RS decoder
*/
#ifdef DEBUG
@ -21,243 +22,247 @@
#endif
int DECODE_RS(
#ifdef FIXED
DTYPE *data, int *eras_pos, int no_eras,int pad){
#else
void *p,DTYPE *data, int *eras_pos, int no_eras){
struct rs *rs = (struct rs *)p;
#ifndef FIXED
void *p,
#endif
int deg_lambda, el, deg_omega;
int i, j, r,k;
DTYPE u,q,tmp,num1,num2,den,discr_r;
DTYPE lambda[NROOTS+1], s[NROOTS]; /* Err+Eras Locator poly
* and syndrome poly */
DTYPE b[NROOTS+1], t[NROOTS+1], omega[NROOTS+1];
DTYPE root[NROOTS], reg[NROOTS+1], loc[NROOTS];
int syn_error, count;
#ifdef FIXED
/* Check pad parameter for validity */
if(pad < 0 || pad >= NN)
return -1;
#endif
/* form the syndromes; i.e., evaluate data(x) at roots of g(x) */
for(i=0;i<NROOTS;i++)
s[i] = data[0];
for(j=1;j<NN-PAD;j++){
for(i=0;i<NROOTS;i++){
if(s[i] == 0){
s[i] = data[j];
} else {
s[i] = data[j] ^ ALPHA_TO[MODNN(INDEX_OF[s[i]] + (FCR+i)*PRIM)];
}
}
}
/* Convert syndromes to index form, checking for nonzero condition */
syn_error = 0;
for(i=0;i<NROOTS;i++){
syn_error |= s[i];
s[i] = INDEX_OF[s[i]];
}
if (!syn_error) {
/* if syndrome is zero, data[] is a codeword and there are no
* errors to correct. So return data[] unmodified
*/
count = 0;
goto finish;
}
memset(&lambda[1],0,NROOTS*sizeof(lambda[0]));
lambda[0] = 1;
if (no_eras > 0) {
/* Init lambda to be the erasure locator polynomial */
lambda[1] = ALPHA_TO[MODNN(PRIM*(NN-1-eras_pos[0]))];
for (i = 1; i < no_eras; i++) {
u = MODNN(PRIM*(NN-1-eras_pos[i]));
for (j = i+1; j > 0; j--) {
tmp = INDEX_OF[lambda[j - 1]];
if(tmp != A0)
lambda[j] ^= ALPHA_TO[MODNN(u + tmp)];
}
}
#if DEBUG >= 1
/* Test code that verifies the erasure locator polynomial just constructed
Needed only for decoder debugging. */
DTYPE *data, int *eras_pos, int no_eras, int calc_syn){
/* find roots of the erasure location polynomial */
for(i=1;i<=no_eras;i++)
reg[i] = INDEX_OF[lambda[i]];
count = 0;
for (i = 1,k=IPRIM-1; i <= NN; i++,k = MODNN(k+IPRIM)) {
q = 1;
for (j = 1; j <= no_eras; j++)
if (reg[j] != A0) {
reg[j] = MODNN(reg[j] + j);
q ^= ALPHA_TO[reg[j]];
}
if (q != 0)
continue;
/* store root and error location number indices */
root[count] = i;
loc[count] = k;
count++;
}
if (count != no_eras) {
printf("count = %d no_eras = %d\n lambda(x) is WRONG\n",count,no_eras);
count = -1;
goto finish;
#ifndef FIXED
struct rs *rs = (struct rs *)p;
#endif
int deg_lambda, el, deg_omega;
int i, j, r,k;
DTYPE u,q,tmp,num1,num2,den,discr_r;
DTYPE lambda[NROOTS+1]; // Err+Eras Locator poly
static DTYPE s[51]; // and syndrome poly
DTYPE b[NROOTS+1], t[NROOTS+1], omega[NROOTS+1];
DTYPE root[NROOTS], reg[NROOTS+1], loc[NROOTS];
int syn_error, count;
if( calc_syn ) {
/* form the syndromes; i.e., evaluate data(x) at roots of g(x) */
for(i=0;i<NROOTS;i++)
s[i] = data[0];
for(j=1;j<NN;j++){
for(i=0;i<NROOTS;i++){
if(s[i] == 0){
s[i] = data[j];
} else {
s[i] = data[j] ^ ALPHA_TO[MODNN(INDEX_OF[s[i]] + (FCR+i)*PRIM)];
}
}
}
/* Convert syndromes to index form, checking for nonzero condition */
syn_error = 0;
for(i=0;i<NROOTS;i++){
syn_error |= s[i];
s[i] = INDEX_OF[s[i]];
}
if (!syn_error) {
/* if syndrome is zero, data[] is a codeword and there are no
* errors to correct. So return data[] unmodified
*/
count = 0;
goto finish;
}
}
memset(&lambda[1],0,NROOTS*sizeof(lambda[0]));
lambda[0] = 1;
if (no_eras > 0) {
/* Init lambda to be the erasure locator polynomial */
lambda[1] = ALPHA_TO[MODNN(PRIM*(NN-1-eras_pos[0]))];
for (i = 1; i < no_eras; i++) {
u = MODNN(PRIM*(NN-1-eras_pos[i]));
for (j = i+1; j > 0; j--) {
tmp = INDEX_OF[lambda[j - 1]];
if(tmp != A0)
lambda[j] ^= ALPHA_TO[MODNN(u + tmp)];
}
}
#if DEBUG >= 1
/* Test code that verifies the erasure locator polynomial just constructed
Needed only for decoder debugging. */
/* find roots of the erasure location polynomial */
for(i=1;i<=no_eras;i++)
reg[i] = INDEX_OF[lambda[i]];
count = 0;
for (i = 1,k=IPRIM-1; i <= NN; i++,k = MODNN(k+IPRIM)) {
q = 1;
for (j = 1; j <= no_eras; j++)
if (reg[j] != A0) {
reg[j] = MODNN(reg[j] + j);
q ^= ALPHA_TO[reg[j]];
}
if (q != 0)
continue;
/* store root and error location number indices */
root[count] = i;
loc[count] = k;
count++;
}
if (count != no_eras) {
printf("count = %d no_eras = %d\n lambda(x) is WRONG\n",count,no_eras);
count = -1;
goto finish;
}
#if DEBUG >= 2
printf("\n Erasure positions as determined by roots of Eras Loc Poly:\n");
for (i = 0; i < count; i++)
printf("%d ", loc[i]);
printf("\n");
printf("\n Erasure positions as determined by roots of Eras Loc Poly:\n");
for (i = 0; i < count; i++)
printf("%d ", loc[i]);
printf("\n");
#endif
#endif
}
for(i=0;i<NROOTS+1;i++)
// printf("%d %d %d\n",i,lambda[i],INDEX_OF[lambda[i]]);
b[i] = INDEX_OF[lambda[i]];
/*
* Begin Berlekamp-Massey algorithm to determine error+erasure
* locator polynomial
*/
r = no_eras;
el = no_eras;
while (++r <= NROOTS) { /* r is the step number */
/* Compute discrepancy at the r-th step in poly-form */
discr_r = 0;
for (i = 0; i < r; i++){
if ((lambda[i] != 0) && (s[r-i-1] != A0)) {
discr_r ^= ALPHA_TO[MODNN(INDEX_OF[lambda[i]] + s[r-i-1])];
}
}
discr_r = INDEX_OF[discr_r]; /* Index form */
if (discr_r == A0) {
/* 2 lines below: B(x) <-- x*B(x) */
memmove(&b[1],b,NROOTS*sizeof(b[0]));
b[0] = A0;
} else {
/* 7 lines below: T(x) <-- lambda(x) - discr_r*x*b(x) */
t[0] = lambda[0];
for (i = 0 ; i < NROOTS; i++) {
if(b[i] != A0)
t[i+1] = lambda[i+1] ^ ALPHA_TO[MODNN(discr_r + b[i])];
else
t[i+1] = lambda[i+1];
}
if (2 * el <= r + no_eras - 1) {
el = r + no_eras - el;
/*
* 2 lines below: B(x) <-- inv(discr_r) *
* lambda(x)
*/
for (i = 0; i <= NROOTS; i++)
b[i] = (lambda[i] == 0) ? A0 : MODNN(INDEX_OF[lambda[i]] - discr_r + NN);
} else {
/* 2 lines below: B(x) <-- x*B(x) */
memmove(&b[1],b,NROOTS*sizeof(b[0]));
b[0] = A0;
}
memcpy(lambda,t,(NROOTS+1)*sizeof(t[0]));
}
}
/* Convert lambda to index form and compute deg(lambda(x)) */
deg_lambda = 0;
for(i=0;i<NROOTS+1;i++){
lambda[i] = INDEX_OF[lambda[i]];
if(lambda[i] != A0)
deg_lambda = i;
}
/* Find roots of the error+erasure locator polynomial by Chien search */
memcpy(&reg[1],&lambda[1],NROOTS*sizeof(reg[0]));
count = 0; /* Number of roots of lambda(x) */
for (i = 1,k=IPRIM-1; i <= NN; i++,k = MODNN(k+IPRIM)) {
q = 1; /* lambda[0] is always 0 */
for (j = deg_lambda; j > 0; j--){
if (reg[j] != A0) {
reg[j] = MODNN(reg[j] + j);
q ^= ALPHA_TO[reg[j]];
}
}
if (q != 0)
continue; /* Not a root */
/* store root (index-form) and error location number */
#if DEBUG>=2
printf("count %d root %d loc %d\n",count,i,k);
#endif
root[count] = i;
loc[count] = k;
/* If we've already found max possible roots,
* abort the search to save time
*/
if(++count == deg_lambda)
break;
}
if (deg_lambda != count) {
/*
* deg(lambda) unequal to number of roots => uncorrectable
* error detected
*/
count = -1;
goto finish;
}
/*
* Compute err+eras evaluator poly omega(x) = s(x)*lambda(x) (modulo
* x**NROOTS). in index form. Also find deg(omega).
*/
deg_omega = deg_lambda-1;
for (i = 0; i <= deg_omega;i++){
tmp = 0;
for(j=i;j >= 0; j--){
if ((s[i - j] != A0) && (lambda[j] != A0))
tmp ^= ALPHA_TO[MODNN(s[i - j] + lambda[j])];
}
omega[i] = INDEX_OF[tmp];
}
/*
* Compute error values in poly-form. num1 = omega(inv(X(l))), num2 =
* inv(X(l))**(FCR-1) and den = lambda_pr(inv(X(l))) all in poly-form
*/
for (j = count-1; j >=0; j--) {
num1 = 0;
for (i = deg_omega; i >= 0; i--) {
if (omega[i] != A0)
num1 ^= ALPHA_TO[MODNN(omega[i] + i * root[j])];
}
num2 = ALPHA_TO[MODNN(root[j] * (FCR - 1) + NN)];
den = 0;
for(i=0;i<NROOTS+1;i++)
b[i] = INDEX_OF[lambda[i]];
/* lambda[i+1] for i even is the formal derivative lambda_pr of lambda[i] */
for (i = min(deg_lambda,NROOTS-1) & ~1; i >= 0; i -=2) {
if(lambda[i+1] != A0)
den ^= ALPHA_TO[MODNN(lambda[i+1] + i * root[j])];
/*
* Begin Berlekamp-Massey algorithm to determine error+erasure
* locator polynomial
*/
r = no_eras;
el = no_eras;
while (++r <= NROOTS) { /* r is the step number */
/* Compute discrepancy at the r-th step in poly-form */
discr_r = 0;
for (i = 0; i < r; i++){
if ((lambda[i] != 0) && (s[r-i-1] != A0)) {
discr_r ^= ALPHA_TO[MODNN(INDEX_OF[lambda[i]] + s[r-i-1])];
}
}
discr_r = INDEX_OF[discr_r]; /* Index form */
if (discr_r == A0) {
/* 2 lines below: B(x) <-- x*B(x) */
memmove(&b[1],b,NROOTS*sizeof(b[0]));
b[0] = A0;
} else {
/* 7 lines below: T(x) <-- lambda(x) - discr_r*x*b(x) */
t[0] = lambda[0];
for (i = 0 ; i < NROOTS; i++) {
if(b[i] != A0)
t[i+1] = lambda[i+1] ^ ALPHA_TO[MODNN(discr_r + b[i])];
else
t[i+1] = lambda[i+1];
}
if (2 * el <= r + no_eras - 1) {
el = r + no_eras - el;
/*
* 2 lines below: B(x) <-- inv(discr_r) *
* lambda(x)
*/
for (i = 0; i <= NROOTS; i++)
b[i] = (lambda[i] == 0) ? A0 : MODNN(INDEX_OF[lambda[i]] - discr_r + NN);
} else {
/* 2 lines below: B(x) <-- x*B(x) */
memmove(&b[1],b,NROOTS*sizeof(b[0]));
b[0] = A0;
}
memcpy(lambda,t,(NROOTS+1)*sizeof(t[0]));
}
}
#if DEBUG >= 1
if (den == 0) {
printf("\n ERROR: denominator = 0\n");
count = -1;
goto finish;
/* Convert lambda to index form and compute deg(lambda(x)) */
deg_lambda = 0;
for(i=0;i<NROOTS+1;i++){
lambda[i] = INDEX_OF[lambda[i]];
if(lambda[i] != A0)
deg_lambda = i;
}
/* Find roots of the error+erasure locator polynomial by Chien search */
memcpy(&reg[1],&lambda[1],NROOTS*sizeof(reg[0]));
count = 0; /* Number of roots of lambda(x) */
for (i = 1,k=IPRIM-1; i <= NN; i++,k = MODNN(k+IPRIM)) {
q = 1; /* lambda[0] is always 0 */
for (j = deg_lambda; j > 0; j--){
if (reg[j] != A0) {
reg[j] = MODNN(reg[j] + j);
q ^= ALPHA_TO[reg[j]];
}
}
if (q != 0)
continue; /* Not a root */
/* store root (index-form) and error location number */
#if DEBUG>=2
printf("count %d root %d loc %d\n",count,i,k);
#endif
/* Apply error to data */
if (num1 != 0 && loc[j] >= PAD) {
data[loc[j]-PAD] ^= ALPHA_TO[MODNN(INDEX_OF[num1] + INDEX_OF[num2] + NN - INDEX_OF[den])];
root[count] = i;
loc[count] = k;
/* If we've already found max possible roots,
* abort the search to save time
*/
if(++count == deg_lambda)
break;
}
}
finish:
if(eras_pos != NULL){
for(i=0;i<count;i++)
eras_pos[i] = loc[i];
}
return count;
if (deg_lambda != count) {
/*
* deg(lambda) unequal to number of roots => uncorrectable
* error detected
*/
count = -1;
goto finish;
}
/*
* Compute err+eras evaluator poly omega(x) = s(x)*lambda(x) (modulo
* x**NROOTS). in index form. Also find deg(omega).
*/
deg_omega = 0;
for (i = 0; i < NROOTS;i++){
tmp = 0;
j = (deg_lambda < i) ? deg_lambda : i;
for(;j >= 0; j--){
if ((s[i - j] != A0) && (lambda[j] != A0))
tmp ^= ALPHA_TO[MODNN(s[i - j] + lambda[j])];
}
if(tmp != 0)
deg_omega = i;
omega[i] = INDEX_OF[tmp];
}
omega[NROOTS] = A0;
/*
* Compute error values in poly-form. num1 = omega(inv(X(l))), num2 =
* inv(X(l))**(FCR-1) and den = lambda_pr(inv(X(l))) all in poly-form
*/
for (j = count-1; j >=0; j--) {
num1 = 0;
for (i = deg_omega; i >= 0; i--) {
if (omega[i] != A0)
num1 ^= ALPHA_TO[MODNN(omega[i] + i * root[j])];
}
num2 = ALPHA_TO[MODNN(root[j] * (FCR - 1) + NN)];
den = 0;
/* lambda[i+1] for i even is the formal derivative lambda_pr of lambda[i] */
for (i = min(deg_lambda,NROOTS-1) & ~1; i >= 0; i -=2) {
if(lambda[i+1] != A0)
den ^= ALPHA_TO[MODNN(lambda[i+1] + i * root[j])];
}
if (den == 0) {
#if DEBUG >= 1
printf("\n ERROR: denominator = 0\n");
#endif
count = -1;
goto finish;
}
/* Apply error to data */
if (num1 != 0) {
data[loc[j]] ^= ALPHA_TO[MODNN(INDEX_OF[num1] + INDEX_OF[num2] + NN - INDEX_OF[den])];
}
}
finish:
if(eras_pos != NULL){
for(i=0;i<count;i++)
eras_pos[i] = loc[i];
}
return count;
}

11
libm65/demod64a.f90
View File

@ -33,10 +33,12 @@ subroutine demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
do j=1,63
s1=-1.e30
fsum=0.
psum=0.
do i=1,64
x=min(afac*s3(i,j)/ave,50.d0)
fs(i)=exp(x)
fsum=fsum+fs(i)
psum=psum + s3(i,j)
if(s3(i,j).gt.s1) then
s1=s3(i,j)
i1=i !Most reliable
@ -50,8 +52,10 @@ subroutine demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
i2=i !Second most reliable
endif
enddo
p1=fs(i1)/fsum !Normalized probabilities
p2=fs(i2)/fsum
! p1=fs(i1)/fsum !Normalized probabilities
! p2=fs(i2)/fsum
p1=s1/psum
p2=s2/psum
mrsym(j)=i1-1
mr2sym(j)=i2-1
mrprob(j)=scale*p1
@ -66,7 +70,8 @@ subroutine demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
sum=sum+mrprob(j)
if(mrprob(j).le.5) nlow=nlow+1
enddo
ntest=sum/63
! ntest=sum/63
ntest=sum
return
end subroutine demod64a

17
libm65/encode_rs.c
View File

@ -13,24 +13,19 @@
#endif
void ENCODE_RS(
#ifdef FIXED
DTYPE *data, DTYPE *bb,int pad){
#else
void *p,DTYPE *data, DTYPE *bb){
#ifndef FIXED
void *p,
#endif
DTYPE *data, DTYPE *bb){
#ifndef FIXED
struct rs *rs = (struct rs *)p;
#endif
int i, j;
DTYPE feedback;
#ifdef FIXED
/* Check pad parameter for validity */
if(pad < 0 || pad >= NN)
return;
#endif
memset(bb,0,NROOTS*sizeof(DTYPE));
for(i=0;i<NN-NROOTS-PAD;i++){
for(i=0;i<NN-NROOTS;i++){
feedback = INDEX_OF[data[i] ^ bb[0]];
if(feedback != A0){ /* feedback term is non-zero */
#ifdef UNNORMALIZED

172
libm65/extract.f90
View File

@ -6,26 +6,36 @@ subroutine extract(s3,nadd,ncount,nhist,decoded,ltext)
integer era(51),dat4(12),indx(64)
integer mrsym(63),mr2sym(63),mrprob(63),mr2prob(63)
logical first,ltext
integer correct(63),itmp(63)
integer param(0:8)
integer h0(0:11),d0(0:11),ne(0:11)
real r0(0:11)
common/test001/s3a(64,63),mrs(63),mrs2(63) !### TEST ONLY ###
! 0 1 2 3 4 5 6 7 8 9 10 11
data h0/41,42,43,43,44,45,46,47,48,48,49,49/
data d0/71,72,73,74,76,77,78,80,81,82,83,83/
! 0 1 2 3 4 5 6 7 8 9 10 11
data r0/0.70,0.72,0.74,0.76,0.78,0.80,0.82,0.84,0.86,0.88,0.90,0.90/
data first/.true./,nsec1/0/
save
nfail=0
1 continue
! call timer('demod64a',0)
call demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
! call timer('demod64a',1)
if(ntest.lt.50 .or. nlow.gt.20) then
ncount=-999 !Flag bad data
go to 900
endif
call pctile(s3,tmp,4032,50,base) ! ### or, use ave from demod64a
s3=s3/base
s3a=s3
1 call demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
! if(ntest.lt.50 .or. nlow.gt.20) then
! ncount=-999 !Flag bad data
! go to 900
! endif
call chkhist(mrsym,nhist,ipk)
if(nhist.ge.20) then
nfail=nfail+1
call pctile(s3,tmp,4032,50,base) ! ### or, use ave from demod64a
do j=1,63
s3(ipk,j)=base
enddo
s3(ipk,1:63)=base
if(nfail.gt.30) then
decoded=' '
ncount=-1
@ -34,74 +44,92 @@ subroutine extract(s3,nadd,ncount,nhist,decoded,ltext)
go to 1
endif
mrs=mrsym
mrs2=mr2sym
call graycode(mrsym,63,-1)
call interleave63(mrsym,-1)
call interleave63(mrprob,-1)
ndec=1
nemax=30 !Was 200 (30)
maxe=8
xlambda=13.0 !Was 12
call graycode(mr2sym,63,-1)
call interleave63(mr2sym,-1)
call interleave63(mr2prob,-1)
if(ndec.eq.1) then
call graycode(mr2sym,63,-1)
call interleave63(mr2sym,-1)
call interleave63(mr2prob,-1)
ntrials=10000
naggressive=10
nsec1=nsec1+1
write(22,rec=1) nsec1,xlambda,maxe,200,mrsym,mrprob,mr2sym,mr2prob
call flush(22)
! call timer('kvasd ',0)
!#ifdef UNIX
! iret=system('./kvasd -q > dev_null')
!#else
iret=system('kvasd -q > dev_null')
!#endif
! call timer('kvasd ',1)
if(iret.ne.0) then
if(first) write(*,1000) iret
1000 format('Error in KV decoder, or no KV decoder present.'/ &
'Return code:',i8,'. Will use BM algorithm.')
ndec=0
first=.false.
go to 20
endif
ntry=0
param=0
read(22,rec=2) nsec2,ncount,dat4
j=nsec2 !Silence compiler warning
decoded=' '
ltext=.false.
if(ncount.ge.0) then
call unpackmsg(dat4,decoded) !Unpack the user message
if(iand(dat4(10),8).ne.0) ltext=.true.
do i=2,12
if(dat4(i).ne.dat4(1)) go to 20
enddo
write(13,*) 'Bad decode?',nhist,nfail,ipk,' ',dat4,decoded
ncount=-1 !Suppress supposedly bogus decodes
decoded=' '
endif
endif
20 if(ndec.eq.0) then
call indexx(63,mrprob,indx)
do i=1,nemax
j=indx(i)
if(mrprob(j).gt.120) then
ne2=i-1
go to 2
endif
era(i)=j-1
enddo
ne2=nemax
2 decoded=' '
do nerase=0,ne2,2
call rs_decode(mrsym,era,nerase,dat4,ncount)
if(ncount.ge.0) then
call unpackmsg(dat4,decoded)
go to 900
endif
enddo
call timer('ftrsd ',0)
call ftrsd2(mrsym,mrprob,mr2sym,mr2prob,ntrials,correct,param,ntry)
call timer('ftrsd ',1)
ncandidates=param(0)
nhard=param(1)
nsoft=param(2)
nerased=param(3)
rtt=0.001*param(4)
ntotal=param(5)
qual=0.001*param(7)
nd0=81
r00=0.87
if(naggressive.eq.10) then
nd0=83
r00=0.90
endif
if(ntotal.le.nd0 .and. rtt.le.r00) nft=1
n=naggressive
if(nhard.gt.50) nft=0
if(nhard.gt.h0(n)) nft=0
if(ntotal.gt.d0(n)) nft=0
if(rtt.gt.r0(n)) nft=0
900 return
ncount=-1
decoded=' '
ltext=.false.
if(nft.gt.0) then
! Turn the corrected symbol array into channel symbols for subtraction;
! pass it back to jt65a via common block "chansyms65".
do i=1,12
dat4(i)=correct(13-i)
enddo
do i=1,63
itmp(i)=correct(64-i)
enddo
correct(1:63)=itmp(1:63)
call interleave63(correct,63,1)
call graycode65(correct,63,1)
call unpackmsg(dat4,decoded) !Unpack the user message
ncount=0
if(iand(dat4(10),8).ne.0) ltext=.true.
endif
900 continue
if(nft.eq.1 .and. nhard.lt.0) decoded=' '
! write(81,3001) naggressive,ncandidates,nhard,ntotal,rtt,qual,decoded
!3001 format(i2,i6,i3,i4,2f8.2,2x,a22)
return
end subroutine extract
subroutine getpp(workdat,p)
integer workdat(63)
integer a(63)
common/test001/s3a(64,63),mrs(63),mrs2(63)
a(1:63)=workdat(63:1:-1)
call interleave63(a,1)
call graycode(a,63,1,a)
psum=0.
do j=1,63
i=a(j)+1
x=s3a(i,j)
s3a(i,j)=0.
psum=psum + x
s3a(i,j)=x
enddo
p=psum/63.0
return
end subroutine getpp

213
libm65/ftrsd2.c Normal file
View File

@ -0,0 +1,213 @@
/*
ftrsd2.c
A soft-decision decoder for the JT65 (63,12) Reed-Solomon code.
This decoding scheme is built around Phil Karn's Berlekamp-Massey
errors and erasures decoder. The approach is inspired by a number of
publications, including the stochastic Chase decoder described
in "Stochastic Chase Decoding of Reed-Solomon Codes", by Leroux et al.,
IEEE Communications Letters, Vol. 14, No. 9, September 2010 and
"Soft-Decision Decoding of Reed-Solomon Codes Using Successive Error-
and-Erasure Decoding," by Soo-Woong Lee and B. V. K. Vijaya Kumar.
Steve Franke K9AN and Joe Taylor K1JT
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <string.h>
#include "rs2.h"
static void *rs;
void getpp_(int workdat[], float *pp);
void ftrsd2_(int mrsym[], int mrprob[], int mr2sym[], int mr2prob[],
int* ntrials0, int correct[], int param[], int ntry[])
{
int rxdat[63], rxprob[63], rxdat2[63], rxprob2[63];
int workdat[63];
int indexes[63];
int era_pos[51];
int i, j, numera, nerr, nn=63;
int ntrials = *ntrials0;
int nhard=0,nhard_min=32768,nsoft=0,nsoft_min=32768;
int ntotal=0,ntotal_min=32768,ncandidates;
int nera_best=0;
float pp,pp1,pp2;
static unsigned int nseed;
// Power-percentage symbol metrics - composite gnnf/hf
int perr[8][8] = {
{ 4, 9, 11, 13, 14, 14, 15, 15},
{ 2, 20, 20, 30, 40, 50, 50, 50},
{ 7, 24, 27, 40, 50, 50, 50, 50},
{13, 25, 35, 46, 52, 70, 50, 50},
{17, 30, 42, 54, 55, 64, 71, 70},
{25, 39, 48, 57, 64, 66, 77, 77},
{32, 45, 54, 63, 66, 75, 78, 83},
{51, 58, 57, 66, 72, 77, 82, 86}};
// Initialize the KA9Q Reed-Solomon encoder/decoder
unsigned int symsize=6, gfpoly=0x43, fcr=3, prim=1, nroots=51;
rs=init_rs_int(symsize, gfpoly, fcr, prim, nroots, 0);
// Reverse the received symbol vectors for BM decoder
for (i=0; i<63; i++) {
rxdat[i]=mrsym[62-i];
rxprob[i]=mrprob[62-i];
rxdat2[i]=mr2sym[62-i];
rxprob2[i]=mr2prob[62-i];
}
// Sort rxprob to find indexes of the least reliable symbols
int k, pass, tmp, nsym=63;
int probs[63];
for (i=0; i<63; i++) {
indexes[i]=i;
probs[i]=rxprob[i];
}
for (pass = 1; pass <= nsym-1; pass++) {
for (k = 0; k < nsym - pass; k++) {
if( probs[k] < probs[k+1] ) {
tmp = probs[k];
probs[k] = probs[k+1];
probs[k+1] = tmp;
tmp = indexes[k];
indexes[k] = indexes[k+1];
indexes[k+1] = tmp;
}
}
}
// See if we can decode using BM HDD, and calculate the syndrome vector.
memset(era_pos,0,51*sizeof(int));
numera=0;
memcpy(workdat,rxdat,sizeof(rxdat));
nerr=decode_rs_int(rs,workdat,era_pos,numera,1);
if( nerr >= 0 ) {
// Hard-decision decoding succeeded. Save codeword and some parameters.
nhard=0;
for (i=0; i<63; i++) {
if( workdat[i] != rxdat[i] ) nhard=nhard+1;
}
memcpy(correct,workdat,63*sizeof(int));
param[0]=0;
param[1]=nhard;
param[2]=0;
param[3]=0;
param[4]=0;
param[5]=0;
param[7]=1000*1000;
ntry[0]=0;
return;
}
/*
Hard-decision decoding failed. Try the FT soft-decision method.
Generate random erasure-locator vectors and see if any of them
decode. This will generate a list of "candidate" codewords. The
soft distance between each candidate codeword and the received
word is estimated by finding the largest (pp1) and second-largest
(pp2) outputs from a synchronized filter-bank operating on the
symbol spectra, and using these to decide which candidate
codeword is "best".
*/
nseed=1; //Seed for random numbers
float ratio;
int thresh, nsum;
int thresh0[63];
ncandidates=0;
nsum=0;
int ii,jj;
for (i=0; i<nn; i++) {
nsum=nsum+rxprob[i];
j = indexes[62-i];
ratio = (float)rxprob2[j]/((float)rxprob[j]+0.01);
ii = 7.999*ratio;
jj = (62-i)/8;
thresh0[i] = 1.3*perr[ii][jj];
}
if(nsum<=0) return;
pp1=0.0;
pp2=0.0;
for (k=1; k<=ntrials; k++) {
memset(era_pos,0,51*sizeof(int));
memcpy(workdat,rxdat,sizeof(rxdat));
/*
Mark a subset of the symbols as erasures.
Run through the ranked symbols, starting with the worst, i=0.
NB: j is the symbol-vector index of the symbol with rank i.
*/
numera=0;
for (i=0; i<nn; i++) {
j = indexes[62-i];
thresh=thresh0[i];
long int ir;
// Generate a random number ir, 0 <= ir < 100 (see POSIX.1-2001 example).
nseed = nseed * 1103515245 + 12345;
ir = (unsigned)(nseed/65536) % 32768;
ir = (100*ir)/32768;
if((ir < thresh ) && numera < 51) {
era_pos[numera]=j;
numera=numera+1;
}
}
nerr=decode_rs_int(rs,workdat,era_pos,numera,0);
if( nerr >= 0 ) {
// We have a candidate codeword. Find its hard and soft distance from
// the received word. Also find pp1 and pp2 from the full array
// s3(64,63) of synchronized symbol spectra.
ncandidates=ncandidates+1;
nhard=0;
nsoft=0;
for (i=0; i<63; i++) {
if(workdat[i] != rxdat[i]) {
nhard=nhard+1;
if(workdat[i] != rxdat2[i]) {
nsoft=nsoft+rxprob[i];
}
}
}
nsoft=63*nsoft/nsum;
ntotal=nsoft+nhard;
getpp_(workdat,&pp);
if(pp>pp1) {
pp2=pp1;
pp1=pp;
nsoft_min=nsoft;
nhard_min=nhard;
ntotal_min=ntotal;
memcpy(correct,workdat,63*sizeof(int));
nera_best=numera;
ntry[0]=k;
} else {
if(pp>pp2 && pp!=pp1) pp2=pp;
}
if(nhard_min <= 41 && ntotal_min <= 71) break;
}
if(k == ntrials) ntry[0]=k;
}
param[0]=ncandidates;
param[1]=nhard_min;
param[2]=nsoft_min;
param[3]=nera_best;
param[4]=1000.0*pp2/pp1;
param[5]=ntotal_min;
param[6]=ntry[0];
param[7]=1000.0*pp2;
param[8]=1000.0*pp1;
if(param[0]==0) param[2]=-1;
return;
}

9
libm65/graycode65.f90 Normal file
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@ -0,0 +1,9 @@
subroutine graycode65(dat,n,idir)
integer dat(n)
do i=1,n
dat(i)=igray(dat(i),idir)
enddo
return
end subroutine graycode65

17
libm65/init_rs.c
View File

@ -30,30 +30,25 @@ void FREE_RS(void *p){
* fcr = first root of RS code generator polynomial, index form
* prim = primitive element to generate polynomial roots
* nroots = RS code generator polynomial degree (number of roots)
* pad = padding bytes at front of shortened block
*/
void *INIT_RS(int symsize,int gfpoly,int fcr,int prim,
int nroots,int pad){
void *INIT_RS(unsigned int symsize,unsigned int gfpoly,unsigned fcr,unsigned prim,
unsigned int nroots){
struct rs *rs;
int i, j, sr,root,iprim;
/* Check parameter ranges */
if(symsize < 0 || symsize > 8*sizeof(DTYPE))
if(symsize > 8*sizeof(DTYPE))
return NULL; /* Need version with ints rather than chars */
if(fcr < 0 || fcr >= (1<<symsize))
if(fcr >= (1<<symsize))
return NULL;
if(prim <= 0 || prim >= (1<<symsize))
if(prim == 0 || prim >= (1<<symsize))
return NULL;
if(nroots < 0 || nroots >= (1<<symsize))
if(nroots >= (1<<symsize))
return NULL; /* Can't have more roots than symbol values! */
if(pad < 0 || pad >= ((1<<symsize) -1 - nroots))
return NULL; /* Too much padding */
rs = (struct rs *)calloc(1,sizeof(struct rs));
rs->mm = symsize;
rs->nn = (1<<symsize)-1;
rs->pad = pad;
rs->alpha_to = (DTYPE *)malloc(sizeof(DTYPE)*(rs->nn+1));
if(rs->alpha_to == NULL){

31
libm65/int.h
View File

@ -7,19 +7,18 @@
/* Reed-Solomon codec control block */
struct rs {
int mm; /* Bits per symbol */
int nn; /* Symbols per block (= (1<<mm)-1) */
DTYPE *alpha_to; /* log lookup table */
DTYPE *index_of; /* Antilog lookup table */
DTYPE *genpoly; /* Generator polynomial */
int nroots; /* Number of generator roots = number of parity symbols */
int fcr; /* First consecutive root, index form */
int prim; /* Primitive element, index form */
int iprim; /* prim-th root of 1, index form */
int pad; /* Padding bytes in shortened block */
unsigned int mm; /* Bits per symbol */
unsigned int nn; /* Symbols per block (= (1<<mm)-1) */
int *alpha_to; /* log lookup table */
int *index_of; /* Antilog lookup table */
int *genpoly; /* Generator polynomial */
unsigned int nroots; /* Number of generator roots = number of parity symbols */
unsigned int fcr; /* First consecutive root, index form */
unsigned int prim; /* Primitive element, index form */
unsigned int iprim; /* prim-th root of 1, index form */
};
static int modnn(struct rs *rs,int x){
static inline int modnn(struct rs *rs,int x){
while (x >= rs->nn) {
x -= rs->nn;
x = (x >> rs->mm) + (x & rs->nn);
@ -33,12 +32,10 @@ static int modnn(struct rs *rs,int x){
#define ALPHA_TO (rs->alpha_to)
#define INDEX_OF (rs->index_of)
#define GENPOLY (rs->genpoly)
//#define NROOTS (rs->nroots)
#define NROOTS (51)
#define NROOTS (rs->nroots)
#define FCR (rs->fcr)
#define PRIM (rs->prim)
#define IPRIM (rs->iprim)
#define PAD (rs->pad)
#define A0 (NN)
#define ENCODE_RS encode_rs_int
@ -47,9 +44,9 @@ static int modnn(struct rs *rs,int x){
#define FREE_RS free_rs_int
void ENCODE_RS(void *p,DTYPE *data,DTYPE *parity);
int DECODE_RS(void *p,DTYPE *data,int *eras_pos,int no_eras);
void *INIT_RS(int symsize,int gfpoly,int fcr,
int prim,int nroots,int pad);
int DECODE_RS(void *p,DTYPE *data,int *eras_pos,int no_eras, int calc_syn);
void *INIT_RS(unsigned int symsize,unsigned int gfpoly,unsigned int fcr,
unsigned int prim,unsigned int nroots);
void FREE_RS(void *p);

16
libm65/rs2.h Normal file
View File

@ -0,0 +1,16 @@
/* User include file for the Reed-Solomon codec
* Copyright 2002, Phil Karn KA9Q
* May be used under the terms of the GNU General Public License (GPL)
*/
/* General purpose RS codec, integer symbols */
void encode_rs_int(void *rs,int *data,int *parity);
int decode_rs_int(void *rs,int *data,int *eras_pos,int no_eras, int calc_syn);
void *init_rs_int(int symsize,int gfpoly,int fcr,
int prim,int nroots,int pad);
void free_rs_int(void *rs);
/* Tables to map from conventional->dual (Taltab) and
* dual->conventional (Tal1tab) bases
*/
extern unsigned char Taltab[],Tal1tab[];

2
mainwindow.cpp
View File

@ -33,7 +33,7 @@ TxTune* g_pTxTune = NULL;
QSharedMemory mem_m65("mem_m65");
QString rev="$Rev$"; //Must update by hand ????
QString Program_Title_Version=" MAP65 v2.5, r" + rev.mid(6,4) +
QString Program_Title_Version=" MAP65 v2.6, r" + rev.mid(6,4) +
" by K1JT";
extern const int RxDataFrequency = 96000;