WSJT-X/lib/fsk4hf/wspr4d.f90
2020-04-15 15:45:07 -05:00

434 lines
12 KiB
Fortran

program wspr4d
! Decode WSPR4 data read from *.c2 or *.wav files.
use packjt77
include 'wspr4_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*32 uwbits
character*77 c77
complex c2(0:NMAX/32-1) !Complex waveform
complex cframe(0:105*NSPS2-1) !Complex waveform
complex cd(0:105*16-1) !Complex waveform
complex c1(0:9,0:3),c0(0:9,0:3)
complex ccor(0:3,103)
complex cp(0:3,0:1)
complex csum,cterm
complex ctwk(NSPS2*4)
real*8 fMHz
real rxdata(2*ND),llr(174),llra(174),llrb(174),llrc(174)
real sbits(174),sbits1(174),sbits3(174)
real ps(0:8191),psbest(0:8191)
real candidates(100,2)
real bitmetrics(206,3)
integer iuniqueword0
integer ihdr(11)
integer*2 iwave(NMAX) !Generated full-length waveform
integer*1 decoded(74),apmask(174),cw(174)
integer*1 hbits(206),hbits1(206),hbits3(206)
integer*1 message(50)
integer*1 rvec(77)
logical badsync,unpk77_success
data rvec/0,1,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,0,0,0,1,0,0,1,1,0,1,1,0, &
1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1, &
0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/
fs=12000.0/NDOWN !Sample rate
dt=1.0/fs !Sample interval (s)
tt=NSPS*dt !Duration of "itone" symbols (s)
baud=1.0/tt !Keying rate for "itone" symbols (baud)
txt=NZ*dt !Transmission length (s)
h=0.50 !h=0.8 seems to be optimum for AWGN sensitivity (not for fading)
twopi=8.0*atan(1.0)
pi=4.0*atan(1.0)
nargs=iargc()
if(nargs.lt.1) then
print*,'Usage: wspr4d [-a <data_dir>] [-f fMHz] [-c ncoh] [-h h] 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
endif
call getarg(iarg,arg)
if(arg(1:2).eq.'-f') then
call getarg(iarg+1,arg)
read(arg,*) fMHz
iarg=iarg+2
endif
ncoh=1
if(arg(1:2).eq.'-h') then
call getarg(iarg+1,arg)
read(arg,*) h
iarg=iarg+2
endif
open(13,file=trim(data_dir)//'/ALL_WSPR.TXT',status='unknown', &
position='append')
xs1=0.0
xs2=0.0
fr1=0.0
fr2=0.0
nav=0
ngood=0
fcsum=0.0
fcsum2=0.0
xsum=0.0
xsum2=0.0
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 wspr4_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
nsync=16
call getcandidate4(c2,npts,fs,fa,fb,ncand,candidates) !First approx for freq
ndecodes=0
do icand=1,1
fc0=candidates(icand,1)
xsnr=candidates(icand,2)
xmax=-1e32
smax=0.0
fc1=fc0-1.50*(fs/416.0)
do if=-20,20
df=if*0.02
fc=fc1+df
do is=300,450,5
call coherent_sync(c2,is,fc,1,sync)
if(sync.gt.smax) then
fc2=fc
isbest=is
smax=sync
endif
enddo
enddo
write(*,*) -1.50*(fs/416),fc1,fc2,isbest
fcsum=fcsum+fc2
fcsum2=fcsum2+fc2*fc2
xsum=xsum+isbest
xsum2=xsum2+isbest*isbest
istart=isbest
fcest=fc2
!genie sync
! istart=375
! fcest=0.0-1.50*(fs/416)
h=1.0
cframe=c2(istart:istart+105*416-1)
call downsample4(cframe,fcest,h,cd)
s2=sum(cd*conjg(cd))/(16*105)
cd=cd/sqrt(s2)
call get_wspr4_bitmetrics(cd,bitmetrics,badsync)
! if(badsync) cycle
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( 67: 74).eq.(/0,1,0,0,1,1,1,0/))
ns3=count(hbits(133:140).eq.(/1,1,1,0,0,1,0,0/))
ns4=count(hbits(199:206).eq.(/1,0,1,1,0,0,0,1/))
nsync_qual=ns1+ns2+ns3+ns4
! if(nsync_qual.lt. 20) cycle
scalefac=2.83
llra( 1: 58)=bitmetrics( 9: 66, 1)
llra( 59:116)=bitmetrics( 75:132, 1)
llra(117:174)=bitmetrics(141:198, 1)
llra=scalefac*llra
llrb( 1: 58)=bitmetrics( 9: 66, 2)
llrb( 59:116)=bitmetrics( 75:132, 2)
llrb(117:174)=bitmetrics(141:198, 2)
llrb=scalefac*llrb
llrc( 1: 58)=bitmetrics( 9: 66, 3)
llrc( 59:116)=bitmetrics( 75:132, 3)
llrc(117:174)=bitmetrics(141:198, 3)
llrc=scalefac*llrc
apmask=0
max_iterations=40
do itry=3,1,-1
if(itry.eq.1) llr=llra
if(itry.eq.2) llr=llrb
if(itry.eq.3) llr=llrc
nhardbp=0
nhardosd=0
call bpdecode174_74(llr,apmask,max_iterations,message,cw,nhardbp,niterations)
Keff=64
if(nhardbp.lt.0) call osd174_74(llr,Keff,apmask,5,message,cw,nhardosd,dmin)
!write(*,*) ifile,nhardosd,dmin
if(nhardbp.ge.0 .or. nhardosd.ge.0) then
write(c77,'(50i1)') message
c77(51:77)='000000000000000000000110000'
call unpack77(c77,0,msg,unpk77_success)
if(unpk77_success .and. index(msg,'K9AN').gt.0) then
write(*,1100) ifile,fc0,xsnr,msg(1:14),itry,nhardbp,nhardosd,dmin
1100 format(i5,2x,f8.2,2x,f8.2,2x,a14,i4,i4,i4,f7.2)
exit
else
cycle
endif
endif
enddo
enddo !candidate list
enddo !files
nfiles=nargs-iarg+1
fcav=fcsum/nfiles
fcvar=fcsum2/nfiles-fcav**2
fcstd=sqrt(fcvar)
xav=xsum/nfiles
xvar=xsum2/nfiles-xav**2
xstd=sqrt(xvar)
write(*,*) 'averages, nfiles: ',nfiles
write(*,*) ' avg freq std avg offset std'
write(*,'(f9.4,2x,f8.4,2x,f8.1,2x,f8.1,2x)') fcav,fcstd,xav,xstd
write(*,1120)
1120 format("<DecodeFinished>")
999 end program wspr4d
subroutine coherent_sync(cd0,i0,f0,itwk,sync)
! Compute sync power for a complex, downsampled FT4 signal.
include 'wspr4_params.f90'
parameter(NP=NMAX/NDOWN,NSS=NSPS/NDOWN)
complex cd0(0:NP-1)
complex csynca(4*NSS),csyncb(4*NSS),csyncc(4*NSS),csyncd(4*NSS)
complex csync2(4*NSS)
complex ctwk(4*NSS)
complex z1,z2,z3,z4
logical first
integer icos4a(0:3),icos4b(0:3),icos4c(0:3),icos4d(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 first/.true./
save first,twopi,csynca,csyncb,csyncc,csyncd,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
do i=0,3
dphia=twopi*icos4a(i)/real(NSS)
dphib=twopi*icos4b(i)/real(NSS)
dphic=twopi*icos4c(i)/real(NSS)
dphid=twopi*icos4d(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))
phia=mod(phia+dphia,twopi)
phib=mod(phib+dphib,twopi)
phic=mod(phic+dphic,twopi)
phid=mod(phid+dphid,twopi)
k=k+1
enddo
enddo
first=.false.
fac=1.0/(4.0*NSS)
endif
i1=i0 !four Costas arrays
i2=i0+33*NSS
i3=i0+66*NSS
i4=i0+99*NSS
z1=0.
z2=0.
z3=0.
z4=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
z1=0.
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.32) 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) z2=sum(cd0(i2:i2+4*NSS-1)*conjg(csync2))
if(itwk.eq.1) csync2=ctwk*csyncc !Tweak the frequency
if(i3.ge.0 .and. i3+4*NSS-1.le.NP-1) z3=sum(cd0(i3:i3+4*NSS-1)*conjg(csync2))
if(itwk.eq.1) csync2=ctwk*csyncd !Tweak the frequency
z4=0.
if(i4.ge.0 .and. i4+4*NSS-1.le.NP-1) then
z4=sum(cd0(i4:i4+4*NSS-1)*conjg(csync2))
elseif( i4+4*NSS-1.gt.NP-1 ) then
npts=(NP-1-i4+1)
if(npts.le.32) then
z4=0.
else
z4=sum(cd0(i4:i4+2*npts-1)*conjg(csync2(1:npts)))
endif
endif
sync = p(z1) + p(z2) + p(z3) + p(z4)
return
end subroutine coherent_sync
subroutine downsample4(ci,f0,h,co)
parameter(NI=105*416,NH=NI/2,NO=NI/26) ! downsample from 416 samples per symbol to 16
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=max(1.0,h)*8.0
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 downsample4
subroutine getcandidate4(c,npts,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
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)-26.0
endif
enddo
return
end subroutine getcandidate4
subroutine wspr4_downsample(iwave,c)
! Input: i*2 data in iwave() at sample rate 12000 Hz
! Output: Complex data in c(), sampled at 375 Hz
include 'wspr4_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 wspr4_downsample