WSJT-X/lib/fsk4hf/ft4sd.f90

474 lines
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Fortran
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program ft4sd
! Decode ft4slow data read from *.c2 or *.wav files.
use packjt77
include 'ft4s_params.f90'
parameter (NSPS2=NSPS/32)
character arg*8,cbits*50,infile*80,fname*16,datetime*11
character ch1*1,ch4*4,cseq*31
character*22 decodes(100)
character*37 msg
character*120 data_dir
character*77 c77
complex c2(0:NMAX/32-1) !Complex waveform
complex cframe(0:144*NSPS2-1) !Complex waveform
complex cd(0:144*20-1) !Complex waveform
real*8 fMHz
real llr(240),llra(240),llrb(240),llrc(240),llrd(240)
real candidates(100,2)
real bitmetrics(288,4)
integer ihdr(11)
integer*2 iwave(NMAX) !Generated full-length waveform
integer*1 apmask(240),cw(240)
integer*1 hbits(288)
integer*1 message101(101)
logical badsync,unpk77_success
fs=12000.0/NDOWN !Sample rate
dt=1.0/fs !Sample interval (s)
tt=NSPS*dt !Duration of "itone" symbols (s)
txt=NZ*dt !Transmission length (s)
hmod=1.0
Keff=91
nargs=iargc()
if(nargs.lt.1) then
print*,'Usage: ft4sd [-a <data_dir>] [-f fMHz] [-h hmod] [-k Keff] file1 [file2 ...]'
go to 999
endif
iarg=1
data_dir="."
call getarg(iarg,arg)
if(arg(1:2).eq.'-a') then
call getarg(iarg+1,data_dir)
iarg=iarg+2
call getarg(iarg,arg)
endif
if(arg(1:2).eq.'-f') then
call getarg(iarg+1,arg)
read(arg,*) fMHz
iarg=iarg+2
call getarg(iarg,arg)
endif
if(arg(1:2).eq.'-h') then
call getarg(iarg+1,arg)
read(arg,*) hmod
iarg=iarg+2
call getarg(iarg,arg)
endif
if(arg(1:2).eq.'-k') then
call getarg(iarg+1,arg)
read(arg,*) Keff
iarg=iarg+2
endif
ngood=0
do ifile=iarg,nargs
call getarg(ifile,infile)
open(10,file=infile,status='old',access='stream')
j1=index(infile,'.c2')
j2=index(infile,'.wav')
if(j1.gt.0) then
read(10,end=999) fname,ntrmin,fMHz,c2
read(fname(8:11),*) nutc
write(datetime,'(i11)') nutc
else if(j2.gt.0) then
read(10,end=999) ihdr,iwave
read(infile(j2-4:j2-1),*) nutc
datetime=infile(j2-11:j2-1)
call ft4s_downsample(iwave,c2)
else
print*,'Wrong file format?'
go to 999
endif
close(10)
fa=-100.0
fb=100.0
fs=12000.0/32.0
npts=120*12000.0/32.0
call getcandidate_ft4s(c2,npts,hmod,fs,fa,fb,ncand,candidates) !First approx for freq
del=1.5*hmod*fs/300.0
ndecodes=0
do icand=1,ncand
fc0=candidates(icand,1)
xsnr=candidates(icand,2)
!write(*,*) 'candidates ',icand,fc0,xsnr
do isync=0,1
if(isync.eq.0) then
fc1=fc0-del
is0=375
ishw=350
isst=30
ifhw=10
df=.1
else if(isync.eq.1) then
fc1=fc2
is0=isbest
ishw=100
isst=10
ifhw=10
df=.02
endif
smax=0.0
do if=-ifhw,ifhw
fc=fc1+df*if
do istart=max(1,is0-ishw),is0+ishw,isst
call coherent_sync_ft4s(c2,istart,hmod,fc,1,sync)
if(sync.gt.smax) then
fc2=fc
isbest=istart
smax=sync
endif
enddo
enddo
! write(*,*) ifile,icand,isync,fc1+del,fc2+del,isbest,smax
enddo
! if(smax .lt. 100.0 ) cycle
!isbest=375
!fc2=-del
do ijitter=0,2
if(ijitter.eq.0) ioffset=0
if(ijitter.eq.1) ioffset=45
if(ijitter.eq.2) ioffset=-45
is0=isbest+ioffset
if(is0.lt.0) cycle
cframe=c2(is0:is0+144*300-1)
call downsample_ft4s(cframe,fc2+del,hmod,cd)
s2=sum(cd*conjg(cd))/(20*144)
cd=cd/sqrt(s2)
call get_ft4s_bitmetrics(cd,hmod,bitmetrics,badsync)
hbits=0
where(bitmetrics(:,1).ge.0) hbits=1
ns1=count(hbits( 1: 8).eq.(/0,0,0,1,1,0,1,1/))
ns2=count(hbits( 57: 64).eq.(/0,1,0,0,1,1,1,0/))
ns3=count(hbits(113:120).eq.(/1,1,1,0,0,1,0,0/))
ns4=count(hbits(169:176).eq.(/1,0,1,1,0,0,0,1/))
ns5=count(hbits(225:232).eq.(/0,0,1,1,1,0,0,1/))
ns6=count(hbits(281:288).eq.(/0,1,1,1,0,0,1,0/))
nsync_qual=ns1+ns2+ns3+ns4+ns5+ns6
! if(nsync_qual.lt. 20) cycle
scalefac=2.83
llra( 1: 48)=bitmetrics( 9: 56, 1)
llra( 49: 96)=bitmetrics( 65:112, 1)
llra( 97:144)=bitmetrics(121:168, 1)
llra(145:192)=bitmetrics(177:224, 1)
llra(193:240)=bitmetrics(233:280, 1)
llra=scalefac*llra
llrb( 1: 48)=bitmetrics( 9: 56, 2)
llrb( 49: 96)=bitmetrics( 65:112, 2)
llrb( 97:144)=bitmetrics(121:168, 2)
llrb(145:192)=bitmetrics(177:224, 2)
llrb(193:240)=bitmetrics(233:280, 2)
llrb=scalefac*llrb
llrc( 1: 48)=bitmetrics( 9: 56, 3)
llrc( 49: 96)=bitmetrics( 65:112, 3)
llrc( 97:144)=bitmetrics(121:168, 3)
llrc(145:192)=bitmetrics(177:224, 3)
llrc(193:240)=bitmetrics(233:280, 3)
llrc=scalefac*llrc
llrd( 1: 48)=bitmetrics( 9: 56, 4)
llrd( 49: 96)=bitmetrics( 65:112, 4)
llrd( 97:144)=bitmetrics(121:168, 4)
llrd(145:192)=bitmetrics(177:224, 4)
llrd(193:240)=bitmetrics(233:280, 4)
llrd=scalefac*llrd
apmask=0
max_iterations=40
do itry=4,1,-1
if(itry.eq.1) llr=llra
if(itry.eq.2) llr=llrb
if(itry.eq.3) llr=llrc
if(itry.eq.4) llr=llrd
nhardbp=0
nhardosd=0
dmin=0.0
call bpdecode240_101(llr,apmask,max_iterations,message101,cw,nhardbp,niterations,nchecks)
! if(nhardbp.lt.0) call osd240_101(llr,Keff,apmask,5,message101,cw,nhardosd,dmin)
maxsuperits=2
ndeep=3 ! use ndeep=3 with Keff=91
if(Keff.eq.77) ndeep=4
if(nhardbp.lt.0) then
! call osd240_101(llr,Keff,apmask,ndeep,message101,cw,nhardosd,dmin)
call decode240_101(llr,Keff,ndeep,apmask,maxsuperits,message101,cw,nhardosd,iter,ncheck,dmin,isuper)
endif
if(nhardbp.ge.0 .or. nhardosd.ge.0) then
write(c77,'(77i1)') message101(1:77)
call unpack77(c77,0,msg,unpk77_success)
if(unpk77_success .and. index(msg,'K9AN').gt.0) then
ngood=ngood+1
write(*,1100) ifile-2,icand,xsnr,isbest/375.0-1.0,1500.0+fc2+del,msg(1:20),itry,nhardbp,nhardosd,dmin,ijitter
1100 format(i5,2x,i5,2x,f6.1,2x,f6.2,2x,f8.2,2x,a20,i4,i4,i4,f7.2,i6)
goto 2002
else
cycle
endif
endif
enddo ! metrics
enddo ! istart jitter
enddo !candidate list
2002 continue
enddo !files
nfiles=nargs-iarg+1
write(*,*) 'nfiles: ',nfiles,' ngood: ',ngood
write(*,1120)
1120 format("<DecodeFinished>")
999 end program ft4sd
subroutine coherent_sync_ft4s(cd0,i0,hmod,f0,itwk,sync)
! Compute sync power for a complex, downsampled FT4s signal.
include 'ft4s_params.f90'
parameter(NP=NMAX/NDOWN,NSS=NSPS/NDOWN)
complex cd0(0:NP-1)
complex csynca(4*NSS),csyncb(4*NSS)
complex csyncc(4*NSS),csyncd(4*NSS)
complex csynce(4*NSS),csyncf(4*NSS)
complex csync2(4*NSS)
complex ctwk(4*NSS)
complex z1,z2,z3,z4,z5,z6
logical first
integer icos4a(0:3),icos4b(0:3)
integer icos4c(0:3),icos4d(0:3)
integer icos4e(0:3),icos4f(0:3)
data icos4a/0,1,3,2/
data icos4b/1,0,2,3/
data icos4c/2,3,1,0/
data icos4d/3,2,0,1/
data icos4e/0,2,3,1/
data icos4f/1,2,0,3/
data first/.true./
save first,twopi,csynca,csyncb,csyncc,csyncd,csynce,csyncf,fac
p(z1)=(real(z1*fac)**2 + aimag(z1*fac)**2)**0.5 !Statement function for power
if( first ) then
twopi=8.0*atan(1.0)
k=1
phia=0.0
phib=0.0
phic=0.0
phid=0.0
phie=0.0
phif=0.0
do i=0,3
dphia=twopi*hmod*icos4a(i)/real(NSS)
dphib=twopi*hmod*icos4b(i)/real(NSS)
dphic=twopi*hmod*icos4c(i)/real(NSS)
dphid=twopi*hmod*icos4d(i)/real(NSS)
dphie=twopi*hmod*icos4e(i)/real(NSS)
dphif=twopi*hmod*icos4f(i)/real(NSS)
do j=1,NSS
csynca(k)=cmplx(cos(phia),sin(phia))
csyncb(k)=cmplx(cos(phib),sin(phib))
csyncc(k)=cmplx(cos(phic),sin(phic))
csyncd(k)=cmplx(cos(phid),sin(phid))
csynce(k)=cmplx(cos(phie),sin(phie))
csyncf(k)=cmplx(cos(phif),sin(phif))
phia=mod(phia+dphia,twopi)
phib=mod(phib+dphib,twopi)
phic=mod(phic+dphic,twopi)
phid=mod(phid+dphid,twopi)
phie=mod(phie+dphie,twopi)
phif=mod(phif+dphif,twopi)
k=k+1
enddo
enddo
first=.false.
fac=1.0/(4.0*NSS)
endif
i1=i0 !four Costas arrays
i2=i0+28*NSS
i3=i0+56*NSS
i4=i0+84*NSS
i5=i0+112*NSS
i6=i0+140*NSS
z1=0.
z2=0.
z3=0.
z4=0.
z5=0.
z6=0.
if(itwk.eq.1) then
dt=1/(12000.0/32.0)
dphi=twopi*f0*dt
phi=0.0
do i=1,4*NSS
ctwk(i)=cmplx(cos(phi),sin(phi))
phi=mod(phi+dphi,twopi)
enddo
endif
if(itwk.eq.1) csync2=ctwk*csynca !Tweak the frequency
if(i1.ge.0 .and. i1+4*NSS-1.le.NP-1) then
z1=sum(cd0(i1:i1+4*NSS-1)*conjg(csync2))
elseif( i1.lt.0 ) then
npts=(i1+4*NSS-1)/2
if(npts.le.40) then
z1=0.
else
z1=sum(cd0(0:i1+4*NSS-1)*conjg(csync2(4*NSS-npts:)))
endif
endif
if(itwk.eq.1) csync2=ctwk*csyncb !Tweak the frequency
if(i2.ge.0 .and. i2+4*NSS-1.le.NP-1) then
z2=sum(cd0(i2:i2+4*NSS-1)*conjg(csync2))
endif
if(itwk.eq.1) csync2=ctwk*csyncc !Tweak the frequency
if(i3.ge.0 .and. i3+4*NSS-1.le.NP-1) then
z3=sum(cd0(i3:i3+4*NSS-1)*conjg(csync2))
endif
if(itwk.eq.1) csync2=ctwk*csyncd !Tweak the frequency
if(i4.ge.0 .and. i4+4*NSS-1.le.NP-1) then
z4=sum(cd0(i4:i4+4*NSS-1)*conjg(csync2))
endif
if(itwk.eq.1) csync2=ctwk*csynce !Tweak the frequency
if(i5.ge.0 .and. i5+4*NSS-1.le.NP-1) then
z5=sum(cd0(i5:i5+4*NSS-1)*conjg(csync2))
endif
if(itwk.eq.1) csync2=ctwk*csyncf !Tweak the frequency
if(i6.ge.0 .and. i6+4*NSS-1.le.NP-1) then
z6=sum(cd0(i6:i6+4*NSS-1)*conjg(csync2))
elseif( i6+4*NSS-1.gt.NP-1 ) then
npts=(NP-1-i6+1)
if(npts.le.40) then
z6=0.
else
z6=sum(cd0(i6:i6+npts-1)*conjg(csync2(1:npts)))
endif
endif
sync = p(z1) + p(z2) + p(z3) + p(z4) + p(z5) + p(z6)
return
end subroutine coherent_sync_ft4s
subroutine downsample_ft4s(ci,f0,hmod,co)
parameter(NI=144*300,NH=NI/2,NO=NI/15) ! downsample from 315 samples per symbol to 20
complex ci(0:NI-1),ct(0:NI-1)
complex co(0:NO-1)
fs=12000.0/32.0
df=fs/NI
ct=ci
call four2a(ct,NI,1,-1,1) !c2c FFT to freq domain
i0=nint(f0/df)
ct=cshift(ct,i0)
co=0.0
co(0)=ct(0)
b=16.0*hmod
do i=1,NO/2
arg=(i*df/b)**2
filt=exp(-arg)
co(i)=ct(i)*filt
co(NO-i)=ct(NI-i)*filt
enddo
co=co/NO
call four2a(co,NO,1,1,1) !c2c FFT back to time domain
return
end subroutine downsample_ft4s
subroutine getcandidate_ft4s(c,npts,hmod,fs,fa,fb,ncand,candidates)
parameter(NFFT1=120*12000/32,NH1=NFFT1/2,NFFT2=120*12000/320,NH2=NFFT2/2)
complex c(0:npts-1) !Complex waveform
complex cc(0:NFFT1-1)
complex csfil(0:NFFT2-1)
complex cwork(0:NFFT2-1)
real bigspec(0:NFFT2-1)
complex c2(0:NFFT1-1) !Short spectra
real s(-NH1+1:NH1) !Coarse spectrum
real ss(-NH1+1:NH1) !Smoothed coarse spectrum
real candidates(100,2)
integer indx(NFFT2-1)
logical first
data first/.true./
save first,w,df,csfil
if(first) then
df=10*fs/NFFT1
csfil=cmplx(0.0,0.0)
do i=0,NFFT2-1
! csfil(i)=exp(-((i-NH2)/32.0)**2) ! revisit this
csfil(i)=exp(-((i-NH2)/(hmod*28.0))**2) ! revisit this
enddo
csfil=cshift(csfil,NH2)
call four2a(csfil,NFFT2,1,-1,1)
first=.false.
endif
cc=cmplx(0.0,0.0)
cc(0:npts-1)=c;
call four2a(cc,NFFT1,1,-1,1)
cc=abs(cc)**2
call four2a(cc,NFFT1,1,-1,1)
cwork(0:NH2)=cc(0:NH2)*conjg(csfil(0:NH2))
cwork(NH2+1:NFFT2-1)=cc(NFFT1-NH2+1:NFFT1-1)*conjg(csfil(NH2+1:NFFT2-1))
call four2a(cwork,NFFT2,1,+1,1)
bigspec=cshift(real(cwork),-NH2)
il=NH2+fa/df
ih=NH2+fb/df
nnl=ih-il+1
call indexx(bigspec(il:il+nnl-1),nnl,indx)
xn=bigspec(il-1+indx(nint(0.3*nnl)))
bigspec=bigspec/xn
ncand=0
do i=il,ih
if((bigspec(i).gt.bigspec(i-1)).and. &
(bigspec(i).gt.bigspec(i+1)).and. &
(bigspec(i).gt.1.15).and.ncand.lt.100) then
ncand=ncand+1
candidates(ncand,1)=df*(i-NH2)
candidates(ncand,2)=10*log10(bigspec(i)-1)-26.5
endif
enddo
return
end subroutine getcandidate_ft4s
subroutine ft4s_downsample(iwave,c)
! Input: i*2 data in iwave() at sample rate 12000 Hz
! Output: Complex data in c(), sampled at 375 Hz
include 'ft4s_params.f90'
parameter (NFFT2=NMAX/32)
integer*2 iwave(NMAX)
complex c(0:NMAX/32-1)
complex c1(0:NFFT2-1)
complex cx(0:NMAX/2)
real x(NMAX)
equivalence (x,cx)
df=12000.0/NMAX
x=iwave
call four2a(x,NMAX,1,-1,0) !r2c FFT to freq domain
i0=nint(1500.0/df)
c1(0)=cx(i0)
do i=1,NFFT2/2
c1(i)=cx(i0+i)
c1(NFFT2-i)=cx(i0-i)
enddo
c1=c1/NFFT2
call four2a(c1,NFFT2,1,1,1) !c2c FFT back to time domain
c=c1(0:NMAX/32-1)
return
end subroutine ft4s_downsample