192 lines
5.8 KiB
Fortran
192 lines
5.8 KiB
Fortran
|
subroutine fast9(id2,narg,line)
|
||
|
|
|
||
|
|
! Decoder for "fast9" modes, JT9E to JT9H.
|
||
|
|
|
||
|
|
parameter (NMAX=30*12000,NSAVE=500)
|
||
|
|
integer*2 id2(0:NMAX)
|
||
|
|
integer narg(0:14)
|
||
|
|
integer*1 i1SoftSymbols(207)
|
||
|
|
integer*1 i1save(207,NSAVE)
|
||
|
|
integer indx(NSAVE)
|
||
|
|
integer*8 count0,count1,clkfreq
|
||
|
|
real s1(720000) !To reserve space. Logically s1(nq,jz)
|
||
|
|
real s2(240,340) !Symbol spectra at quarter-symbol steps
|
||
|
|
real ss2(0:8,85) !Folded symbol spectra
|
||
|
|
real ss3(0:7,69) !Folded spectra without sync symbols
|
||
|
|
real s(1500)
|
||
|
|
real ccfsave(NSAVE)
|
||
|
|
real t0save(NSAVE)
|
||
|
|
real t1save(NSAVE)
|
||
|
|
real freqSave(NSAVE)
|
||
|
|
real t(6)
|
||
|
|
character*22 msg !Decoded message
|
||
|
|
character*80 line(100)
|
||
|
|
data nsubmode0/-1/,ntot/0/
|
||
|
|
save s1,nsubmode0,ntot
|
||
|
|
|
||
|
|
! Parameters from GUI are in narg():
|
||
|
|
nutc=narg(0) !UTC
|
||
|
|
npts=min(narg(1),NMAX) !Number of samples in id2 (12000 Hz)
|
||
|
|
nsubmode=narg(2) !0=A 1=B 2=C 3=D 4=E 5=F 6=G 7=H
|
||
|
|
if(nsubmode.lt.4) go to 900
|
||
|
|
newdat=narg(3) !1==> new data, compute symbol spectra
|
||
|
|
minsync=narg(4) !Lower sync limit
|
||
|
|
npick=narg(5)
|
||
|
|
t0=0.001*narg(6)
|
||
|
|
t1=0.001*narg(7)
|
||
|
|
maxlines=narg(8) !Max # of decodes to return to caller
|
||
|
|
nmode=narg(9)
|
||
|
|
nrxfreq=narg(10) !Targer Rx audio frequency (Hz)
|
||
|
|
ntol=narg(11) !Search range, +/- ntol (Hz)
|
||
|
|
|
||
|
|
tmid=npts*0.5/12000.0
|
||
|
|
line(1:100)(1:1)=char(0)
|
||
|
|
s=0
|
||
|
|
s2=0
|
||
|
|
nsps=60 * 2**(7-nsubmode) !Samples per sysbol
|
||
|
|
nfft=2*nsps !FFT size
|
||
|
|
nh=nfft/2
|
||
|
|
nq=nfft/4
|
||
|
|
istep=nsps/4 !Symbol spectra at quarter-symbol steps
|
||
|
|
jz=npts/istep
|
||
|
|
df=12000.0/nfft !FFT bin width
|
||
|
|
db1=db(2500.0/df)
|
||
|
|
nfa=max(200,nrxfreq-ntol) !Lower frequency limit
|
||
|
|
nfb=min(nrxfreq+ntol,2500) !Upper frequency limit
|
||
|
|
nline=0
|
||
|
|
t=0.
|
||
|
|
|
||
|
|
if(newdat.eq.1 .or. nsubmode.ne.nsubmode0) then
|
||
|
|
call system_clock(count0,clkfreq)
|
||
|
|
call spec9f(id2,npts,nsps,s1,jz,nq) !Compute symbol spectra, s1
|
||
|
|
call system_clock(count1,clkfreq)
|
||
|
|
t(1)=t(1)+float(count1-count0)/float(clkfreq)
|
||
|
|
endif
|
||
|
|
|
||
|
|
nsubmode0=nsubmode
|
||
|
|
tmsg=nsps*85.0/12000.0
|
||
|
|
limit=2000
|
||
|
|
nlen0=0
|
||
|
|
i1=0
|
||
|
|
i2=0
|
||
|
|
ccfsave=0.
|
||
|
|
do ilength=1,14
|
||
|
|
nlen=1.4142136**(ilength-1)
|
||
|
|
if(nlen.gt.jz/340) nlen=jz/340
|
||
|
|
if(nlen.eq.nlen0) cycle
|
||
|
|
nlen0=nlen
|
||
|
|
|
||
|
|
db0=db(float(nlen))
|
||
|
|
jlen=nlen*340
|
||
|
|
jstep=jlen/4 !### Is this about right? ###
|
||
|
|
if(nsubmode.ge.6) jstep=jlen/2
|
||
|
|
|
||
|
|
do ja=1,jz-jlen,jstep
|
||
|
|
jb=ja+jlen-1
|
||
|
|
call system_clock(count0,clkfreq)
|
||
|
|
call foldspec9f(s1,nq,jz,ja,jb,s2) !Fold symbol spectra into s2
|
||
|
|
call system_clock(count1,clkfreq)
|
||
|
|
t(2)=t(2)+float(count1-count0)/float(clkfreq)
|
||
|
|
|
||
|
|
! Find sync; put sync'ed symbol spectra into ss2 and ss3
|
||
|
|
! Might want to do a peakup in DT and DF, then re-compute symbol spectra.
|
||
|
|
|
||
|
|
call system_clock(count0,clkfreq)
|
||
|
|
call sync9f(s2,nq,nfa,nfb,ss2,ss3,lagpk,ipk,ccfbest)
|
||
|
|
call system_clock(count1,clkfreq)
|
||
|
|
t(3)=t(3)+float(count1-count0)/float(clkfreq)
|
||
|
|
|
||
|
|
i1=i1+1
|
||
|
|
if(ccfbest.lt.30.0) cycle
|
||
|
|
call system_clock(count0,clkfreq)
|
||
|
|
call softsym9f(ss2,ss3,i1SoftSymbols) !Compute soft symbols
|
||
|
|
call system_clock(count1,clkfreq)
|
||
|
|
t(4)=t(4)+float(count1-count0)/float(clkfreq)
|
||
|
|
|
||
|
|
i2=i2+1
|
||
|
|
ccfsave(i2)=ccfbest
|
||
|
|
i1save(1:207,i2)=i1SoftSymbols
|
||
|
|
t0=(ja-1)*istep/12000.0
|
||
|
|
t1=(jb-1)*istep/12000.0
|
||
|
|
t0save(i2)=t0
|
||
|
|
t1save(i2)=t1
|
||
|
|
freq=ipk*df
|
||
|
|
freqSave(i2)=freq
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
nsaved=i2
|
||
|
|
|
||
|
|
ccfsave(1:nsaved)=-ccfsave(1:nsaved)
|
||
|
|
call system_clock(count0,clkfreq)
|
||
|
|
indx=0
|
||
|
|
call indexx(ccfsave,nsaved,indx)
|
||
|
|
call system_clock(count1,clkfreq)
|
||
|
|
t(5)=t(5)+float(count1-count0)/float(clkfreq)
|
||
|
|
|
||
|
|
ccfsave(1:nsaved)=-ccfsave(1:nsaved)
|
||
|
|
|
||
|
|
do iter=1,2
|
||
|
|
! do isave=1,nsaved
|
||
|
|
do isave=1,50
|
||
|
|
i2=indx(isave)
|
||
|
|
if(i2.lt.1 .or. i2.gt.nsaved) cycle !### Why needed? ###
|
||
|
|
t0=t0save(i2)
|
||
|
|
t1=t1save(i2)
|
||
|
|
if(iter.eq.1 .and. t1.lt.tmid) cycle
|
||
|
|
if(iter.eq.2 .and. t1.ge.tmid) cycle
|
||
|
|
ccfbest=ccfsave(i2)
|
||
|
|
i1SoftSymbols=i1save(1:207,i2)
|
||
|
|
freq=freqSave(i2)
|
||
|
|
call system_clock(count0,clkfreq)
|
||
|
|
call jt9fano(i1SoftSymbols,limit,nlim,msg) !Invoke Fano decoder
|
||
|
|
call system_clock(count1,clkfreq)
|
||
|
|
t(6)=t(6)+float(count1-count0)/float(clkfreq)
|
||
|
|
|
||
|
|
i=t0*12000.0
|
||
|
|
kz=(t1-t0)/0.02
|
||
|
|
smax=0.
|
||
|
|
do k=1,kz
|
||
|
|
sq=0.
|
||
|
|
do n=1,240
|
||
|
|
i=i+1
|
||
|
|
x=id2(i)
|
||
|
|
sq=sq+x*x
|
||
|
|
enddo
|
||
|
|
s(k)=sq/240.
|
||
|
|
smax=max(s(k),smax)
|
||
|
|
enddo
|
||
|
|
call pctile(s,kz,35,base)
|
||
|
|
snr=smax/(1.1*base) - 1.0
|
||
|
|
nsnr=-20
|
||
|
|
if(snr.gt.0.0) nsnr=nint(db(snr))
|
||
|
|
|
||
|
|
! write(72,3002) nutc,iter,isave,nlen,tmid,t0,t1,ccfbest, &
|
||
|
|
! nint(freq),nlim,msg
|
||
|
|
!3002 format(i6.6,i1,i4,i3,4f6.1,i5,i7,1x,a22)
|
||
|
|
|
||
|
|
if(msg.ne.' ') then
|
||
|
|
|
||
|
|
! Display multiple decodes only if they differ:
|
||
|
|
do n=1,nline
|
||
|
|
if(index(line(n),msg).gt.1) go to 100
|
||
|
|
enddo
|
||
|
|
!### Might want to use decoded message to get a complete estimate of S/N.
|
||
|
|
nline=nline+1
|
||
|
|
write(line(nline),1000) nutc,nsnr,t0,nint(freq),msg,char(0)
|
||
|
|
1000 format(i6.6,i4,f5.1,i5,1x,'@ ',1x,a22,a1)
|
||
|
|
ntot=ntot+1
|
||
|
|
! write(70,5001) nsaved,isave,nline,maxlines,ntot,nutc,msg
|
||
|
|
!5001 format(5i5,i7.6,1x,a22)
|
||
|
|
if(nline.ge.maxlines) go to 900
|
||
|
|
endif
|
||
|
|
100 continue
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
|
||
|
|
900 continue
|
||
|
|
! write(*,6001) t,t(6)/sum(t)
|
||
|
|
!6001 format(7f10.3)
|
||
|
|
|
||
|
|
return
|
||
|
|
end subroutine fast9
|