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Fix several flaws in the loop-over-NB logic in the FST4 decoder.

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This commit is contained in:
Joe Taylor 2020-09-19 10:08:42 -04:00
parent 2af01ebaa1
commit 0ab3e5116f
1 changed files with 33 additions and 31 deletions
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64
lib/fst4_decode.f90
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@ -229,7 +229,6 @@ contains
npct=0
nb=nexp_decode/256 - 2
if(nb.ge.0) npct=nb
inb0=0
inb1=20
inb2=5
if(nb.eq.-1) then
@ -240,42 +239,44 @@ contains
inb1=0 !Fixed NB value, 0 to 25%
ipct(0)=npct
endif
if(iwspr.eq.1) then !FST4W
!300 Hz wide noise-fit window
nfa=max(100,nint(nfqso+1.5*baud-150))
nfb=min(4800,nint(nfqso+1.5*baud+150))
fa=max(100,nint(nfqso+1.5*baud-ntol)) ! signal search window
fb=min(4800,nint(nfqso+1.5*baud+ntol))
else if(single_decode) then
fa=max(100,nint(nfa+1.5*baud))
fb=min(4800,nint(nfb+1.5*baud))
! extend noise fit 100 Hz outside of search window
nfa=max(100,nfa-100)
nfb=min(4800,nfb+100)
else
fa=max(100,nint(nfa+1.5*baud))
fb=min(4800,nint(nfb+1.5*baud))
! extend noise fit 100 Hz outside of search window
nfa=max(100,nfa-100)
nfb=min(4800,nfb+100)
endif
ndecodes=0
decodes=' '
do inb=inb0,inb1,inb2
do inb=0,inb1,inb2
if(nb.lt.0) npct=inb
call blanker(iwave,nfft1,ndropmax,npct,c_bigfft)
! The big fft is done once and is used for calculating the smoothed spectrum
! and also for downconverting/downsampling each candidate.
call four2a(c_bigfft,nfft1,1,-1,0) !r2c
nhicoh=1
nsyncoh=8
if(iwspr.eq.1) then !FST4W
nfa=max(100,nint(nfqso+1.5*baud-150)) !300 Hz wide noise-fit window
nfb=min(4800,nint(nfqso+1.5*baud+150))
fa=max(100,nint(nfqso+1.5*baud-ntol)) ! signal search window
fb=min(4800,nint(nfqso+1.5*baud+ntol))
else if(single_decode) then
fa=max(100,nint(nfa+1.5*baud))
fb=min(4800,nint(nfb+1.5*baud))
nfa=max(100,nfa-100) ! extend noise fit 100 Hz outside of search window
nfb=min(4800,nfb+100)
else
fa=max(100,nint(nfa+1.5*baud))
fb=min(4800,nint(nfb+1.5*baud))
nfa=max(100,nfa-100) ! extend noise fit 100 Hz outside of search window
nfb=min(4800,nfb+100)
endif
minsync=1.20
if(ntrperiod.eq.15) minsync=1.15
! Get first approximation of candidate frequencies
call get_candidates_fst4(c_bigfft,nfft1,nsps,hmod,fs,fa,fb,nfa,nfb, &
minsync,ncand,candidates0)
minsync,ncand,candidates0)
isbest=0
fc2=0.
do icand=1,ncand
@ -307,10 +308,10 @@ contains
do icand=1,ncand
fc=candidates0(icand,3)
isbest=nint(candidates0(icand,4))
do ic2=1,ncand
do ic2=icand+1,ncand
fc2=candidates0(ic2,3)
isbest2=nint(candidates0(ic2,4))
if(ic2.ne.icand .and. fc2.gt.0.0) then
if(fc2.gt.0.0) then
if(abs(fc2-fc).lt.0.10*baud) then ! same frequency
if(abs(isbest2-isbest).le.2) then
candidates0(ic2,3)=-1
@ -327,7 +328,7 @@ contains
endif
enddo
ncand=ic
! If FST4 and Single Decode is not checked, then find candidates within
! 20 Hz of nfqso and put them at the top of the list
if(iwspr.eq.0 .and. .not.single_decode) then
@ -475,7 +476,7 @@ contains
do i=1,ndecodes
if(decodes(i).eq.msg) idupe=1
enddo
if(idupe.eq.1) goto 2002
if(idupe.eq.1) goto 800
ndecodes=ndecodes+1
decodes(ndecodes)=msg
@ -522,14 +523,15 @@ contains
endif
call this%callback(nutc,smax1,nsnr,xdt,fsig,msg, &
iaptype,qual,ntrperiod,lwspr,fmid,w50)
goto 2002
if(iwspr.eq.0 .and. nb.lt.0) go to 900
goto 800
endif
enddo ! metrics
enddo ! istart jitter
2002 enddo !candidate list
enddo
800 enddo !candidate list
enddo ! noise blanker loop
return
900 return
end subroutine decode
subroutine sync_fst4(cd0,i0,f0,hmod,ncoh,np,nss,ntr,fs,sync)