mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-09-12 08:16:39 -04:00
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7701 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
500 lines
14 KiB
Fortran
500 lines
14 KiB
Fortran
program wspr5d
|
|
|
|
! Decode WSPR-LF data read from *.c5 or *.wav files.
|
|
|
|
! WSPR-LF is a potential WSPR-like mode intended for use at LF and MF.
|
|
! It uses an LDPC (300,60) code, OQPSK modulation, and 5 minute T/R sequences.
|
|
!
|
|
! Still to do: find and decode more than one signal in the specified passband.
|
|
|
|
! include 'wsprlf_params.f90'
|
|
|
|
parameter (NDOWN=30)
|
|
parameter (KK=60)
|
|
parameter (ND=300)
|
|
parameter (NS=109)
|
|
parameter (NR=3)
|
|
parameter (NN=NR+NS+ND)
|
|
parameter (NSPS0=8640)
|
|
parameter (NSPS=16)
|
|
parameter (N2=2*NSPS)
|
|
parameter (NZ=NSPS*NN)
|
|
parameter (NZ400=288*NN)
|
|
parameter (NMAX=300*12000)
|
|
|
|
character arg*8,message*22,cbits*50,infile*80,fname*16,datetime*11
|
|
character*120 data_dir
|
|
complex csync(0:NZ-1) !Sync symbols only, from cbb
|
|
complex c400(0:NZ400-1) !Complex waveform
|
|
complex c(0:NZ-1) !Complex waveform
|
|
complex cd(0:NZ-1) !Complex waveform
|
|
complex ca(0:NZ-1) !Complex waveform
|
|
complex zz
|
|
real*8 fMHz
|
|
real rxdata(ND),llr(ND) !Soft symbols
|
|
real pp(32) !Shaped pulse for OQPSK
|
|
real sbits(412),softbits(9)
|
|
real fpks(20)
|
|
integer id(NS+ND) !NRZ values (+/-1) for Sync and Data
|
|
integer isync(48) !Long sync vector
|
|
integer ib13(13) !Barker 13 code
|
|
integer ihdr(11)
|
|
integer*8 n8
|
|
integer*2 iwave(NMAX) !Generated full-length waveform
|
|
integer*1 idat(7)
|
|
integer*1 decoded(KK),apmask(ND),cw(ND)
|
|
integer*1 hbits(412),bits(13)
|
|
data ib13/1,1,1,1,1,-1,-1,1,1,-1,1,-1,1/
|
|
|
|
nargs=iargc()
|
|
if(nargs.lt.2) then
|
|
print*,'Usage: wspr5d [-a <data_dir>] [-f fMHz] 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
|
|
|
|
open(13,file=trim(data_dir)//'/ALL_WSPR.TXT',status='unknown', &
|
|
position='append')
|
|
maxn=8 !Default value
|
|
twopi=8.0*atan(1.0)
|
|
fs=NSPS*12000.0/NSPS0 !Sample rate
|
|
dt=1.0/fs !Sample interval (s)
|
|
tt=NSPS*dt !Duration of "itone" symbols (s)
|
|
ts=2*NSPS*dt !Duration of OQPSK symbols (s)
|
|
baud=1.0/tt !Keying rate for "itone" symbols (baud)
|
|
txt=NZ*dt !Transmission length (s)
|
|
|
|
do i=1,32 !Half-sine pulse shape
|
|
pp(i)=sin(0.5*(i-1)*twopi/(32))
|
|
enddo
|
|
n8=z'cbf089223a51'
|
|
do i=1,48
|
|
isync(i)=-1
|
|
if(iand(n8,1).eq.1) isync(i)=1
|
|
n8=n8/2
|
|
enddo
|
|
|
|
! Define array id() for sync symbols
|
|
id=0
|
|
do j=1,48 !First group of 48
|
|
id(2*j-1)=2*isync(j)
|
|
enddo
|
|
do j=1,13 !Barker 13 code
|
|
id(j+96)=2*ib13(j)
|
|
enddo
|
|
do j=1,48 !Second group of 48
|
|
id(2*j+109)=2*isync(j)
|
|
enddo
|
|
|
|
csync=0.
|
|
do j=1,205
|
|
if(abs(id(j)).eq.2) then
|
|
ia=nint((j-0.5)*N2)
|
|
ib=ia+N2-1
|
|
csync(ia:ib)=pp*id(j)/abs(id(j))
|
|
endif
|
|
enddo
|
|
|
|
do ifile=iarg,nargs
|
|
call getarg(ifile,infile)
|
|
open(10,file=infile,status='old',access='stream')
|
|
j1=index(infile,'.c5')
|
|
j2=index(infile,'.wav')
|
|
if(j1.gt.0) then
|
|
read(10,end=999) fname,ntrmin,fMHz,c400
|
|
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 wspr5_downsample(iwave,c400)
|
|
else
|
|
print*,'Wrong file format?'
|
|
go to 999
|
|
endif
|
|
close(10)
|
|
|
|
fa=100.0
|
|
fb=150.0
|
|
fs400=400.0
|
|
call getfc1(c400,fs400,fa,fb,fc1,xsnr) !First approx for freq
|
|
!write(*,*) datetime,'initial guess ',fc1
|
|
npeaks=5
|
|
call getfc2(c400,npeaks,fs400,fc1,fpks) !Refined freq
|
|
|
|
do idf=1,npeaks ! consider the top npeak peaks
|
|
fc2=fpks(idf)
|
|
call downsample(c400,fc1+fc2,cd)
|
|
s2=sum(cd*conjg(cd))/(16*412)
|
|
cd=cd/sqrt(s2)
|
|
do is=0,8 ! dt search range is narrow, to save time.
|
|
idt=is/2
|
|
if( mod(is,2).eq. 1 ) idt=-(is+1)/2
|
|
xdt=real(22+idt)/22.222 - 1.0
|
|
ca=cshift(cd,22+idt)
|
|
do iseq=1,3 ! try sequence estimation lengths of 3, 6, and 9 bits.
|
|
k=1-2*iseq
|
|
nseq=iseq*3
|
|
do i=1,408,iseq*4
|
|
k=k+iseq*2
|
|
j=(i+1)*16
|
|
call mskseqdet(nseq,ca(j),pp,id(k),softbits,1,phase)
|
|
hbits(i:i+iseq*4)=bits
|
|
sbits(i:i+iseq*4)=bits
|
|
|
|
sbits(i+1)=softbits(1)
|
|
sbits(i+2)=softbits(2)
|
|
if( id(k+1) .ne. 0 ) sbits(i+2)=id(k+1)*25
|
|
sbits(i+3)=softbits(3)
|
|
|
|
if( iseq .ge. 2 ) then
|
|
sbits(i+5)=softbits(4)
|
|
sbits(i+6)=softbits(5)
|
|
if( id(k+3) .ne. 0 ) sbits(i+6)=id(k+3)*25
|
|
sbits(i+7)=softbits(6)
|
|
if( iseq .eq. 3 ) then
|
|
sbits(i+9)=softbits(7)
|
|
sbits(i+10)=softbits(8)
|
|
if( id(k+5) .ne. 0 ) sbits(i+10)=id(k+5)*25
|
|
sbits(i+11)=softbits(9)
|
|
endif
|
|
endif
|
|
enddo
|
|
j=1
|
|
do i=1,205
|
|
if( abs(id(i)) .ne. 2 ) then
|
|
rxdata(j)=sbits(2*i-1)
|
|
j=j+1
|
|
endif
|
|
enddo
|
|
do i=1,204
|
|
rxdata(j)=sbits(2*i)
|
|
j=j+1
|
|
enddo
|
|
rxav=sum(rxdata)/ND
|
|
rx2av=sum(rxdata*rxdata)/ND
|
|
rxsig=sqrt(rx2av-rxav*rxav)
|
|
rxdata=rxdata/rxsig
|
|
! sigma=0.84
|
|
sigma=1.20
|
|
llr=2*rxdata/(sigma*sigma)
|
|
apmask=0
|
|
max_iterations=40
|
|
ifer=0
|
|
nbadcrc=0
|
|
call bpdecode300(llr,apmask,max_iterations,decoded,niterations,cw)
|
|
! niterations will be equal to the Hamming distance between hard received word and the codeword
|
|
if(niterations.lt.0) call osd300(llr,3,decoded,niterations,cw)
|
|
if(niterations.ge.0) call chkcrc10(decoded,nbadcrc)
|
|
if(niterations.lt.0 .or. nbadcrc.ne.0) ifer=1
|
|
if( ifer.eq.0 ) then
|
|
write(cbits,1200) decoded(1:50)
|
|
1200 format(50i1)
|
|
read(cbits,1202) idat
|
|
1202 format(6b8,b2)
|
|
idat(7)=ishft(idat(7),6)
|
|
call wqdecode(idat,message,itype)
|
|
nsnr=nint(xsnr)
|
|
freq=fMHz + 1.d-6*(fc1+fc2)
|
|
nfdot=0
|
|
write(13,1210) datetime,0,nsnr,xdt,freq,message,nfdot
|
|
1210 format(a11,2i4,f6.2,f12.7,2x,a22,i3)
|
|
write(*,1212) datetime(8:11),nsnr,xdt,freq,nfdot,message,'*',idf,nseq,is,niterations
|
|
1212 format(a4,i4,f5.1,f11.6,i3,2x,a22,a1,i3,i3,i3,i4)
|
|
goto 888
|
|
endif
|
|
enddo !iseq
|
|
enddo
|
|
enddo
|
|
888 continue
|
|
enddo
|
|
|
|
write(*,1120)
|
|
1120 format("<DecodeFinished>")
|
|
|
|
999 end program wspr5d
|
|
|
|
subroutine getmetric(ib,ps,xmet)
|
|
real ps(0:511)
|
|
xm1=0
|
|
xm0=0
|
|
do i=0,511
|
|
if( iand(i/ib,1) .eq. 1 .and. ps(i) .gt. xm1 ) xm1=ps(i)
|
|
if( iand(i/ib,1) .eq. 0 .and. ps(i) .gt. xm0 ) xm0=ps(i)
|
|
enddo
|
|
xmet=xm1-xm0
|
|
return
|
|
end subroutine getmetric
|
|
|
|
subroutine mskseqdet(ns,cdat,pp,bsync,softbits,ncoh,phase)
|
|
!
|
|
! Detect sequences of 3, 6, or 9 bits (ns).
|
|
! Sync bits are assumed to be known.
|
|
!
|
|
complex cdat(16*12),cbest(16*12),cideal(16*12)
|
|
complex cdf(16*12),cfac,zz
|
|
real cm(0:511),cmbest(0:511)
|
|
real pp(32),softbits(9)
|
|
integer bit(13),bestbits(13),sgn(13)
|
|
integer bsync(7)
|
|
|
|
twopi=8.0*atan(1.0)
|
|
dt=30.0*18.0/12000.0
|
|
cmax=0;
|
|
fbest=0.0;
|
|
np=2**ns-1
|
|
idfmax=40
|
|
if( ncoh .eq. 1 ) idfmax=0
|
|
do idf=0,idfmax
|
|
if( mod(idf,2).eq.1 ) deltaf=idf/2*0.02
|
|
if( mod(idf,2).eq.1 ) deltaf=-(idf+1)/2*0.02
|
|
dphi=twopi*deltaf*dt
|
|
cfac=cmplx(cos(dphi),sin(dphi))
|
|
cdf=1.0
|
|
do i=2,16*(ns-1)
|
|
cdf(i)=cdf(i-1)*cfac
|
|
enddo
|
|
|
|
cm=0
|
|
ibflag=0
|
|
do i=0,np
|
|
bit(1)=(bsync(1)+2)/4
|
|
bit(2)=iand(i/(2**(ns-1)),1)
|
|
bit(3)=iand(i/(2**(ns-2)),1)
|
|
if( bsync(2).ne.0 ) then ! force the barker bits
|
|
bit(3)=(bsync(2)+2)/4
|
|
endif
|
|
bit(4)=iand(i/(2**(ns-3)),1)
|
|
bit(5)=(bsync(3)+2)/4
|
|
|
|
if( ns .ge. 6 ) then
|
|
bit(6)=iand(i/(2**(ns-4)),1)
|
|
bit(7)=iand(i/(2**(ns-5)),1)
|
|
if( bsync(4).ne.0 ) then ! force the barker bits
|
|
bit(7)=(bsync(4)+2)/4
|
|
endif
|
|
bit(8)=iand(i/(2**(ns-6)),1)
|
|
bit(9)=(bsync(5)+2)/4
|
|
if( ns .eq. 9 ) then
|
|
bit(10)=iand(i/4,1)
|
|
bit(11)=iand(i/2,1)
|
|
if( bsync(6).ne.0 ) then ! force the barker bits
|
|
bit(11)=(bsync(6)+2)/4
|
|
endif
|
|
bit(12)=iand(i/1,1)
|
|
bit(13)=(bsync(7)+2)/4
|
|
endif
|
|
endif
|
|
|
|
sgn=2*bit-1
|
|
cideal(1:16) =cmplx(sgn(1)*pp(17:32),sgn(2)*pp(1:16))
|
|
cideal(17:32) =cmplx(sgn(3)*pp(1:16),sgn(2)*pp(17:32))
|
|
cideal(33:48) =cmplx(sgn(3)*pp(17:32),sgn(4)*pp(1:16))
|
|
cideal(49:64) =cmplx(sgn(5)*pp(1:16),sgn(4)*pp(17:32))
|
|
if( ns .ge. 6 ) then
|
|
cideal(65:80) =cmplx(sgn(5)*pp(17:32),sgn(6)*pp(1:16))
|
|
cideal(81:96) =cmplx(sgn(7)*pp(1:16),sgn(6)*pp(17:32))
|
|
cideal(97:112) =cmplx(sgn(7)*pp(17:32),sgn(8)*pp(1:16))
|
|
cideal(113:128)=cmplx(sgn(9)*pp(1:16),sgn(8)*pp(17:32))
|
|
if( ns .eq. 9 ) then
|
|
cideal(129:144) =cmplx(sgn(9)*pp(17:32),sgn(10)*pp(1:16))
|
|
cideal(145:160) =cmplx(sgn(11)*pp(1:16),sgn(10)*pp(17:32))
|
|
cideal(161:176) =cmplx(sgn(11)*pp(17:32),sgn(12)*pp(1:16))
|
|
cideal(177:192)=cmplx(sgn(13)*pp(1:16),sgn(12)*pp(17:32))
|
|
endif
|
|
endif
|
|
cideal=cideal*cdf
|
|
cm(i)=abs(sum(cdat(1:64*ns/3)*conjg(cideal(1:64*ns/3))))/1.e3
|
|
if( cm(i) .gt. cmax ) then
|
|
ibflag=1
|
|
cmax=cm(i)
|
|
bestbits=bit
|
|
cbest=cideal
|
|
fbest=deltaf
|
|
zz=sum(cdat*conjg(cbest))/1.e3
|
|
phase=atan2(imag(zz),real(zz))
|
|
endif
|
|
enddo
|
|
if( ibflag .eq. 1 ) then ! new best found
|
|
cmbest=cm
|
|
endif
|
|
enddo
|
|
softbits=0.0
|
|
call getmetric(1,cmbest,softbits(ns))
|
|
call getmetric(2,cmbest,softbits(ns-1))
|
|
call getmetric(4,cmbest,softbits(ns-2))
|
|
if( ns .ge. 6 ) then
|
|
call getmetric(8,cmbest,softbits(ns-3))
|
|
call getmetric(16,cmbest,softbits(ns-4))
|
|
call getmetric(32,cmbest,softbits(ns-5))
|
|
if( ns .eq. 9 ) then
|
|
call getmetric(64,cmbest,softbits(3))
|
|
call getmetric(128,cmbest,softbits(2))
|
|
call getmetric(256,cmbest,softbits(1))
|
|
endif
|
|
endif
|
|
end subroutine mskseqdet
|
|
|
|
subroutine downsample(ci,f0,co)
|
|
parameter(NI=412*288,NO=NI/18)
|
|
complex ci(0:NI-1),ct(0:NI-1)
|
|
complex co(0:NO-1)
|
|
|
|
df=400.0/NI
|
|
ct=ci
|
|
call four2a(ct,NI,1,-1,1) !c2c FFT to freq domain
|
|
i0=nint(f0/df)
|
|
co=0.0
|
|
co(0)=ct(i0)
|
|
b=3.0
|
|
do i=1,NO/2
|
|
arg=(i*df/b)**2
|
|
filt=exp(-arg)
|
|
co(i)=ct(i0+i)*filt
|
|
co(NO-i)=ct(i0-i)*filt
|
|
enddo
|
|
co=co/NO
|
|
call four2a(co,NO,1,1,1) !c2c FFT back to time domain
|
|
return
|
|
end subroutine downsample
|
|
|
|
subroutine getfc1(c,fs,fa,fb,fc1,xsnr)
|
|
|
|
! include 'wsprlf_params.f90'
|
|
parameter (NZ=288*412)
|
|
parameter (NSPS=288)
|
|
parameter (N2=2*NSPS)
|
|
parameter (NFFT1=16*NSPS)
|
|
parameter (NH1=NFFT1/2)
|
|
|
|
complex c(0:NZ-1) !Complex waveform
|
|
complex c2(0:NFFT1-1) !Short spectra
|
|
real s(-NH1+1:NH1) !Coarse spectrum
|
|
nspec=NZ/N2
|
|
df1=fs/NFFT1
|
|
s=0.
|
|
do k=1,nspec
|
|
ia=(k-1)*N2
|
|
ib=ia+N2-1
|
|
c2(0:N2-1)=c(ia:ib)
|
|
c2(N2:)=0.
|
|
call four2a(c2,NFFT1,1,-1,1)
|
|
do i=0,NFFT1-1
|
|
j=i
|
|
if(j.gt.NH1) j=j-NFFT1
|
|
s(j)=s(j) + real(c2(i))**2 + aimag(c2(i))**2
|
|
enddo
|
|
enddo
|
|
! call smo121(s,NFFT1)
|
|
smax=0.
|
|
ipk=0
|
|
fc1=0.
|
|
ia=nint(fa/df1)
|
|
ib=nint(fb/df1)
|
|
do i=ia,ib
|
|
f=i*df1
|
|
if(s(i).gt.smax) then
|
|
smax=s(i)
|
|
ipk=i
|
|
fc1=f
|
|
endif
|
|
! write(51,3001) f,s(i),db(s(i))
|
|
! 3001 format(f10.3,e12.3,f10.3)
|
|
enddo
|
|
|
|
! The following is for testing SNR calibration:
|
|
sp3n=(s(ipk-1)+s(ipk)+s(ipk+1)) !Sig + 3*noise
|
|
base=(sum(s)-sp3n)/(NFFT1-3.0) !Noise per bin
|
|
psig=sp3n-3*base !Sig only
|
|
pnoise=(2500.0/df1)*base !Noise in 2500 Hz
|
|
xsnr=db(psig/pnoise)
|
|
xsnr=xsnr+5.0
|
|
return
|
|
end subroutine getfc1
|
|
|
|
subroutine getfc2(c,npeaks,fs,fc1,fpks)
|
|
|
|
! include 'wsprlf_params.f90'
|
|
parameter (NZ=288*412)
|
|
parameter (NSPS=288)
|
|
parameter (N2=2*NSPS)
|
|
parameter (NFFT1=16*NSPS)
|
|
parameter (NH1=NFFT1/2)
|
|
|
|
complex c(0:NZ-1) !Complex waveform
|
|
complex cs(0:NZ-1) !For computing spectrum
|
|
real a(5)
|
|
real freqs(413),sp2(413),fpks(npeaks)
|
|
integer pkloc(1)
|
|
|
|
df=fs/NZ
|
|
baud=fs/NSPS
|
|
a(1)=-fc1
|
|
a(2:5)=0.
|
|
call twkfreq1(c,NZ,fs,a,cs) !Mix down by fc1
|
|
|
|
! Filter, square, then FFT to get refined carrier frequency fc2.
|
|
call four2a(cs,NZ,1,-1,1) !To freq domain
|
|
|
|
ia=nint(0.75*baud/df)
|
|
cs(ia:NZ-1-ia)=0. !Save only freqs around fc1
|
|
! do i=1,NZ/2
|
|
! filt=1/(1+((i*df)**2/(0.50*baud)**2)**8)
|
|
! cs(i)=cs(i)*filt
|
|
! cs(NZ+1-i)=cs(NZ+1-i)*filt
|
|
! enddo
|
|
call four2a(cs,NZ,1,1,1) !Back to time domain
|
|
cs=cs/NZ
|
|
cs=cs*cs !Square the data
|
|
call four2a(cs,NZ,1,-1,1) !Compute squared spectrum
|
|
! Find two peaks separated by baud
|
|
pmax=0.
|
|
fc2=0.
|
|
! ja=nint(0.3*baud/df)
|
|
ja=nint(0.5*baud/df)
|
|
k=1
|
|
sp2=0.0
|
|
do j=-ja,ja
|
|
f2=j*df
|
|
ia=nint((f2-0.5*baud)/df)
|
|
if(ia.lt.0) ia=ia+NZ
|
|
ib=nint((f2+0.5*baud)/df)
|
|
p=real(cs(ia))**2 + aimag(cs(ia))**2 + &
|
|
real(cs(ib))**2 + aimag(cs(ib))**2
|
|
if(p.gt.pmax) then
|
|
pmax=p
|
|
fc2=0.5*f2
|
|
endif
|
|
freqs(k)=0.5*f2
|
|
sp2(k)=p
|
|
k=k+1
|
|
! write(52,1200) f2,p,db(p)
|
|
!1200 format(f10.3,2f15.3)
|
|
enddo
|
|
|
|
do i=1,npeaks
|
|
pkloc=maxloc(sp2)
|
|
ipk=pkloc(1)
|
|
fpks(i)=freqs(ipk)
|
|
ipk0=max(1,ipk-2)
|
|
ipk1=min(413,ipk+2)
|
|
! ipk0=ipk
|
|
! ipk1=ipk
|
|
sp2(ipk0:ipk1)=0.0
|
|
enddo
|
|
return
|
|
end subroutine getfc2
|