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Improving decoder performance

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This commit is contained in:
Jordan Sherer 2020-04-30 22:48:20 -04:00
parent 1a10ab5d13
commit 59ce3b1118
5 changed files with 84 additions and 67 deletions
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2
lib/ft8/ft8_params.f90
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@ -4,7 +4,7 @@ parameter (NCOSTAS=1) !Which JS8 Costas Arrays to use (1=origina
parameter (NSPS=1920, NTXDUR=15, NDOWNSPS=32, NDD=100, JZ=62) ! 50 Hz 6.250 baud 16 wpm -25.0dB (1.0Eb/N0) 12.64s
parameter (AZ=12000.0/(1.0*NSPS)*0.8d0) !Dedupe overlap in Hz
parameter (AZ=12000.0/(1.0*NSPS)*0.64d0) !Dedupe overlap in Hz
parameter (ASTART=0.5) !Start delay in seconds
parameter (ASYNCMIN=1.5) !Minimum Sync

135
lib/js8/js8dec.f90
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@ -21,6 +21,7 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
real bmeta(3*ND),bmetb(3*ND),bmetap(3*ND)
real llr(3*ND),llra(3*ND),llr0(3*ND),llr1(3*ND),llrap(3*ND) !Soft symbols
real dd0(NMAX)
integer icos
integer*1 decoded(KK),decoded0(KK),apmask(3*ND),cw(3*ND)
integer*1 msgbits(KK)
integer apsym(KK)
@ -34,6 +35,7 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
complex cd0(0:NP-1)
complex ctwk(7*NSPS/NDOWN)
complex csymb(NDOWNSPS)
complex cs(0:7, NN)
logical first,newdat,lsubtract,lapon,lapcqonly,nagain
equivalence (s1,s1sort)
data mcq/1,1,1,1,1,0,1,0,0,0,0,0,1,0,0,0,0,0,1,1,0,0,0,1,1,0,0,1/
@ -100,7 +102,7 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
delfbest=0.
ibest=0
if(NWRITELOG.eq.0) then
if(NWRITELOG.eq.1) then
write(*,*) '<DecodeDebug> downsampling', f1, fs2, dt2
flush(6)
endif
@ -120,7 +122,7 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
do idt=i0-NQSYMBOL,i0+NQSYMBOL !Search over +/- one quarter symbol
call syncjs8d(cd0,icos,idt,ctwk,0,sync)
if(NWRITELOG.eq.0) then
if(NWRITELOG.eq.1) then
write(*,*) '<DecodeDebug> ', 'idt', idt, 'sync', sync
flush(6)
endif
@ -131,7 +133,7 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
enddo
xdt2=ibest*dt2 !Improved estimate for DT
if(NWRITELOG.eq.0) then
if(NWRITELOG.eq.1) then
write(*,*) '<DecodeDebug> ', 'xdt2', xdt2, 'ibest', ibest
flush(6)
endif
@ -149,7 +151,7 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
phi=mod(phi+dphi,twopi)
enddo
call syncjs8d(cd0,icos,i0,ctwk,1,sync)
if(NWRITELOG.eq.0) then
if(NWRITELOG.eq.1) then
write(*,*) '<DecodeDebug> ', 'df', delf, 'sync', sync
flush(6)
endif
@ -165,11 +167,11 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
f1=f1+delfbest !Improved estimate of DF
if(NWRITELOG.eq.0) then
write(*,*) '<DecodeDebug> ', 'twk', xdt, f1, smax
write(*,*) '<DecodeDebug> twk', xdt, f1, smax
flush(6)
endif
call syncjs8d(cd0,icos,i0,ctwk,2,sync)
call syncjs8d(cd0,icos,i0,ctwk,0,sync)
j=0
do k=1,NN
@ -206,6 +208,10 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
call timer('badnsync', 0)
nbadcrc=1
call timer('badnsync', 1)
if(NWRITELOG.eq.0) then
write(*,*) '<DecodeDebug> bad sync', nsync
flush(6)
endif
return
endif
@ -226,7 +232,8 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
i4=3*j-2
i2=3*j-1
i1=3*j
! Max amplitude
! Max amplitude
ps=s1(0:7,j)
r1=max(ps(1),ps(3),ps(5),ps(7))-max(ps(0),ps(2),ps(4),ps(6))
r2=max(ps(2),ps(3),ps(6),ps(7))-max(ps(0),ps(1),ps(4),ps(5))
@ -237,7 +244,8 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
bmetap(i4)=r4
bmetap(i2)=r2
bmetap(i1)=r1
! Max log metric
! Max log metric
psl=log(ps+1e-32)
r1=max(psl(1),psl(3),psl(5),psl(7))-max(psl(0),psl(2),psl(4),psl(6))
r2=max(psl(2),psl(3),psl(6),psl(7))-max(psl(0),psl(1),psl(4),psl(5))
@ -246,64 +254,65 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
bmetb(i2)=r2
bmetb(i1)=r1
! Metric for Cauchy noise
r1=log(ps(1)**3+ps(3)**3+ps(5)**3+ps(7)**3)- &
log(ps(0)**3+ps(2)**3+ps(4)**3+ps(6)**3)
r2=log(ps(2)**3+ps(3)**3+ps(6)**3+ps(7)**3)- &
log(ps(0)**3+ps(1)**3+ps(4)**3+ps(5)**3)
r4=log(ps(4)**3+ps(5)**3+ps(6)**3+ps(7)**3)- &
log(ps(0)**3+ps(1)**3+ps(2)**3+ps(3)**3)
! Metric for AWGN, no fading
bscale=2.5
b0=bessi0(bscale*ps(0))
b1=bessi0(bscale*ps(1))
b2=bessi0(bscale*ps(2))
b3=bessi0(bscale*ps(3))
b4=bessi0(bscale*ps(4))
b5=bessi0(bscale*ps(5))
b6=bessi0(bscale*ps(6))
b7=bessi0(bscale*ps(7))
r1=log(b1+b3+b5+b7)-log(b0+b2+b4+b6)
r2=log(b2+b3+b6+b7)-log(b0+b1+b4+b5)
r4=log(b4+b5+b6+b7)-log(b0+b1+b2+b3)
! ! Metric for Cauchy noise
! r1=log(ps(1)**3+ps(3)**3+ps(5)**3+ps(7)**3)- &
! log(ps(0)**3+ps(2)**3+ps(4)**3+ps(6)**3)
! r2=log(ps(2)**3+ps(3)**3+ps(6)**3+ps(7)**3)- &
! log(ps(0)**3+ps(1)**3+ps(4)**3+ps(5)**3)
! r4=log(ps(4)**3+ps(5)**3+ps(6)**3+ps(7)**3)- &
! log(ps(0)**3+ps(1)**3+ps(2)**3+ps(3)**3)
!
! ! Metric for AWGN, no fading
! bscale=2.5
! b0=bessi0(bscale*ps(0))
! b1=bessi0(bscale*ps(1))
! b2=bessi0(bscale*ps(2))
! b3=bessi0(bscale*ps(3))
! b4=bessi0(bscale*ps(4))
! b5=bessi0(bscale*ps(5))
! b6=bessi0(bscale*ps(6))
! b7=bessi0(bscale*ps(7))
! r1=log(b1+b3+b5+b7)-log(b0+b2+b4+b6)
! r2=log(b2+b3+b6+b7)-log(b0+b1+b4+b5)
! r4=log(b4+b5+b6+b7)-log(b0+b1+b2+b3)
if(nQSOProgress .eq. 0 .or. nQSOProgress .eq. 5) then
! When bits 88:115 are set as ap bits, bit 115 lives in symbol 39 along
! with no-ap bits 116 and 117. Take care of metrics for bits 116 and 117.
if(j.eq.39) then ! take care of bits that live in symbol 39
if(apsym(28).lt.0) then
bmetap(i2)=max(ps(2),ps(3))-max(ps(0),ps(1))
bmetap(i1)=max(ps(1),ps(3))-max(ps(0),ps(2))
else
bmetap(i2)=max(ps(6),ps(7))-max(ps(4),ps(5))
bmetap(i1)=max(ps(5),ps(7))-max(ps(4),ps(6))
endif
endif
endif
! if(nQSOProgress .eq. 0 .or. nQSOProgress .eq. 5) then
! ! When bits 88:115 are set as ap bits, bit 115 lives in symbol 39 along
! ! with no-ap bits 116 and 117. Take care of metrics for bits 116 and 117.
! if(j.eq.39) then ! take care of bits that live in symbol 39
! if(apsym(28).lt.0) then
! bmetap(i2)=max(ps(2),ps(3))-max(ps(0),ps(1))
! bmetap(i1)=max(ps(1),ps(3))-max(ps(0),ps(2))
! else
! bmetap(i2)=max(ps(6),ps(7))-max(ps(4),ps(5))
! bmetap(i1)=max(ps(5),ps(7))-max(ps(4),ps(6))
! endif
! endif
! endif
! When bits 116:143 are set as ap bits, bit 115 lives in symbol 39 along
! with ap bits 116 and 117. Take care of metric for bit 115.
if(j.eq.39) then ! take care of bit 115
iii=2*(apsym(29)+1)/2 + (apsym(30)+1)/2 ! known values of bits 116 & 117
if(iii.eq.0) bmetap(i4)=ps(4)-ps(0)
if(iii.eq.1) bmetap(i4)=ps(5)-ps(1)
if(iii.eq.2) bmetap(i4)=ps(6)-ps(2)
if(iii.eq.3) bmetap(i4)=ps(7)-ps(3)
endif
! ! When bits 116:143 are set as ap bits, bit 115 lives in symbol 39 along
! ! with ap bits 116 and 117. Take care of metric for bit 115.
! if(j.eq.39) then ! take care of bit 115
! iii=2*(apsym(29)+1)/2 + (apsym(30)+1)/2 ! known values of bits 116 & 117
! if(iii.eq.0) bmetap(i4)=ps(4)-ps(0)
! if(iii.eq.1) bmetap(i4)=ps(5)-ps(1)
! if(iii.eq.2) bmetap(i4)=ps(6)-ps(2)
! if(iii.eq.3) bmetap(i4)=ps(7)-ps(3)
! endif
! bit 144 lives in symbol 48 and will be 1 if it is set as an ap bit.
! take care of metrics for bits 142 and 143
if(j.eq.48) then ! bit 144 is always 1
bmetap(i4)=max(ps(5),ps(7))-max(ps(1),ps(3))
bmetap(i2)=max(ps(3),ps(7))-max(ps(1),ps(5))
endif
! ! bit 144 lives in symbol 48 and will be 1 if it is set as an ap bit.
! ! take care of metrics for bits 142 and 143
! if(j.eq.48) then ! bit 144 is always 1
! bmetap(i4)=max(ps(5),ps(7))-max(ps(1),ps(3))
! bmetap(i2)=max(ps(3),ps(7))-max(ps(1),ps(5))
! endif
! bit 154 lives in symbol 52 and will be 0 if it is set as an ap bit
! take care of metrics for bits 155 and 156
if(j.eq.52) then ! bit 154 will be 0 if it is set as an ap bit.
bmetap(i2)=max(ps(2),ps(3))-max(ps(0),ps(1))
bmetap(i1)=max(ps(1),ps(3))-max(ps(0),ps(2))
endif
! ! bit 154 lives in symbol 52 and will be 0 if it is set as an ap bit
! ! take care of metrics for bits 155 and 156
! if(j.eq.52) then ! bit 154 will be 0 if it is set as an ap bit.
! bmetap(i2)=max(ps(2),ps(3))-max(ps(0),ps(1))
! bmetap(i1)=max(ps(1),ps(3))-max(ps(0),ps(2))
! endif
enddo
@ -404,7 +413,7 @@ subroutine js8dec(dd0,icos,newdat,nQSOProgress,nfqso,nftx,ndepth,lapon,lapcqonly
niterations)
call timer('bpd174 ',1)
if(NWRITELOG.eq.1) then
if(NWRITELOG.eq.0) then
write(*,*) '<DecodeDebug> bpd174', ipass, nharderrors, dmin
flush(6)
endif

11
lib/js8/syncjs8.f90
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@ -12,6 +12,7 @@ subroutine syncjs8(dd,icos,nfa,nfb,syncmin,nfqso,s,candidate,ncand,sbase)
real candidate0(3,200)
real candidate(3,200)
real dd(NMAX)
integer icos
integer jpeak(NH1)
integer indx(NH1)
integer ii(1)
@ -52,6 +53,7 @@ subroutine syncjs8(dd,icos,nfa,nfb,syncmin,nfqso,s,candidate,ncand,sbase)
enddo
savg=savg + s(1:NH1,j) !Average spectrum
enddo
call baselinejs8(savg,nfa,nfb,sbase)
ia=max(1,nint(nfa/df)) ! min freq
@ -147,7 +149,7 @@ subroutine syncjs8(dd,icos,nfa,nfb,syncmin,nfqso,s,candidate,ncand,sbase)
if(k.ge.200) exit
n=ia + indx(iz+1-i) - 1
if(red(n).lt.syncmin.or.isnan(red(n))) exit
if(NWRITELOG.eq.1) then
if(NWRITELOG.eq.0) then
write(*,*) '<DecodeDebug> red candidate', red(n), n*df, (jpeak(n)-1)*tstep
flush(6)
endif
@ -158,6 +160,11 @@ subroutine syncjs8(dd,icos,nfa,nfb,syncmin,nfqso,s,candidate,ncand,sbase)
enddo
ncand=k
! Put nfqso at top of list
do i=1,ncand
if(abs(candidate0(1,i)-nfqso).lt.10.0) candidate0(1,i)=-candidate0(1,i)
enddo
! Save only the best of near-dupe freqs.
do i=1,ncand
if(i.ge.2) then
@ -165,7 +172,7 @@ subroutine syncjs8(dd,icos,nfa,nfb,syncmin,nfqso,s,candidate,ncand,sbase)
fdiff=abs(candidate0(1,i))-abs(candidate0(1,j))
if(abs(fdiff).lt.AZ) then ! note: this dedupe difference is dependent on symbol spacing
if(NWRITELOG.eq.1) then
write(*,*) '<DecodeDebug> candidate dupe', fdiff, candidate0(1,i), candidate0(1,j)
write(*,*) '<DecodeDebug> dupe', fdiff, candidate0(1,i), candidate0(3,i), candidate0(1,j), candidate0(3,j)
flush(6)
endif
if(candidate0(3,i).ge.candidate0(3,j)) candidate0(3,j)=0.

1
lib/js8/syncjs8d.f90
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@ -10,6 +10,7 @@ subroutine syncjs8d(cd0,icos,i0,ctwk,itwk,sync)
complex ctwk(7*NDOWNSPS)
complex z1,z2,z3
logical first
integer icos
data first/.true./
save first,twopi,csynca,csyncb,csyncc

2
lib/js8a_decode.f90
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@ -101,7 +101,7 @@ contains
xdt=candidate(2,icand)
xbase=10.0**(0.1*(sbase(nint(f1/(12000.0/NFFT1)))-40.0)) ! 3.125Hz
if(NWRITELOG.eq.1) then
if(NWRITELOG.eq.0) then
write(*,*) '<DecodeDebug> candidate', icand, 'f1', f1, 'sync', sync, 'xdt', xdt, 'xbase', xbase
flush(6)
endif