mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-12-01 08:39:03 -05:00
75111eef66
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@8664 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
440 lines
12 KiB
Fortran
440 lines
12 KiB
Fortran
program wsprdpskd
|
|
|
|
! Decode WSPRDPSK data read from *.c2 or *.wav files.
|
|
|
|
! Currently configured to use (204,68) r=1/3 LDPC code, regular column weight 3.
|
|
! 50 data bits + 14 bit CRC + 4 "0" bits. The 4 "0" bits are unused bits that
|
|
! are not transmitted. At the decoder, these bits are treated as "AP" bits.
|
|
! This shortens the code to (200,64) r=0.32, slightly decreasing the code rate.
|
|
! Frame format is:
|
|
! d100 p32 d100 (232) channel symbols
|
|
!
|
|
use crc
|
|
include 'wsprdpsk_params.f90'
|
|
parameter(NMAX=120*12000)
|
|
character arg*8,message*22,cbits*50,infile*80,fname*16,datetime*11
|
|
character*22 decodes(100)
|
|
character*120 data_dir
|
|
character*32 uwbits
|
|
character*68 dmsg
|
|
complex c2(0:120*12000/30-1) !Complex waveform
|
|
complex cframe(0:232*200-1) !Complex waveform
|
|
complex cd(0:240*10-1) !Complex waveform
|
|
complex cs(0:240)
|
|
complex c1(0:9,0:1),c0(0:9,0:1)
|
|
complex ccor(0:1,232)
|
|
complex csum,cterm
|
|
real*8 fMHz
|
|
real rxdata(ND),llr(204) !Soft symbols
|
|
real sbits(232),sbits1(232),sbits3(232)
|
|
real ps(0:8191),psbest(0:8191)
|
|
real candidates(100,2)
|
|
integer iuniqueword0
|
|
integer isync(200) !Unique word
|
|
integer isync2(232)
|
|
integer ipreamble(16) !Preamble vector
|
|
integer ihdr(11)
|
|
integer*2 iwave(NMAX) !Generated full-length waveform
|
|
integer*1,target :: idat(9)
|
|
integer*1 decoded(68),apmask(204),cw(204)
|
|
integer*1 hbits(232),hbits1(232),hbits3(232)
|
|
integer*1 b(14),bbest(14)
|
|
data ipreamble/1,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1/
|
|
data iuniqueword0/z'30C9E8AD'/
|
|
|
|
write(uwbits,'(b32.32)') iuniqueword0
|
|
read(uwbits,'(32i1)') isync(1:32)
|
|
read(uwbits,'(32i1)') isync(33:64)
|
|
read(uwbits,'(32i1)') isync(65:96)
|
|
read(uwbits,'(32i1)') isync(97:128)
|
|
read(uwbits,'(32i1)') isync(129:160)
|
|
read(uwbits,'(32i1)') isync(161:192)
|
|
read(uwbits,'(8i1)') isync(193:200)
|
|
|
|
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=1.00 !h=0.8 seems to be optimum for AWGN sensitivity (not for fading)
|
|
twopi=8.0*atan(1.0)
|
|
|
|
isync2(1:100)=isync(1:100)
|
|
isync2(101:104)=0 ! This is *not* backwards.
|
|
isync2(105:112)=1
|
|
isync2(113:116)=0
|
|
isync2(117:216)=isync(101:200)
|
|
|
|
dphi=twopi*baud*(h/2.0)*dt*20 ! dt*20 is samp interval after downsample
|
|
do j=0,1
|
|
if(j.eq.0) then
|
|
dphi0=-3*dphi
|
|
dphi1=+1*dphi
|
|
else
|
|
dphi0=-1*dphi
|
|
dphi1=+3*dphi
|
|
endif
|
|
phi0=0.0
|
|
phi1=0.0
|
|
do i=0,9
|
|
c1(i,j)=cmplx(cos(phi1),sin(phi1))
|
|
c0(i,j)=cmplx(cos(phi0),sin(phi0))
|
|
phi1=mod(phi1+dphi1,twopi)
|
|
phi0=mod(phi0+dphi0,twopi)
|
|
enddo
|
|
enddo
|
|
|
|
nargs=iargc()
|
|
if(nargs.lt.1) then
|
|
print*,'Usage: wsprdpskd [-a <data_dir>] [-f fMHz] [-c ncoh] 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
|
|
npdi=16
|
|
if(arg(1:2).eq.'-c') then
|
|
call getarg(iarg+1,arg)
|
|
read(arg,*) ncoh
|
|
iarg=iarg+2
|
|
npdi=16/ncoh
|
|
endif
|
|
! write(*,*) 'ncoh: ',ncoh,' npdi: ',npdi
|
|
|
|
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
|
|
|
|
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 wsprdpsk_downsample(iwave,c2)
|
|
else
|
|
print*,'Wrong file format?'
|
|
go to 999
|
|
endif
|
|
close(10)
|
|
|
|
fa=-10.0
|
|
fb=10.0
|
|
fs=12000.0/30.0
|
|
npts=120*12000.0/30.0
|
|
! call getcandidate2(c2,npts,fs,fa,fb,ncand,candidates) !First approx for freq
|
|
ncand=1
|
|
candidates(1,1)=0.0
|
|
candidates(1,2)=-28
|
|
ndecodes=0
|
|
do icand=1,ncand
|
|
fc0=candidates(icand,1)
|
|
xsnr=candidates(icand,2)
|
|
call dsdpsk(c2,fc0,cd)
|
|
i0=40
|
|
do i=0,231
|
|
cs(i)=cd(i0+10*i)/5e4
|
|
enddo
|
|
! 2-bit differential detection
|
|
do i=1,231
|
|
! do i=1,232
|
|
sbits(i)=-real(cs(i)*conjg(cs(i-1))) !2 symbol dpsk
|
|
! sbits(i)=real(cs(i-1)) !for coherent dpsk
|
|
! sbits(i)=real(cs(i)) !for coherent bpsk
|
|
enddo
|
|
! do i=1,231
|
|
! sbits3(i)=-sbits(i+1)*sbits(i) ! for coherent dpsk
|
|
! enddo
|
|
|
|
! detect a differentially encoded block of symbols using the
|
|
! Divsalar and Simon approach, except that we estimate only
|
|
! the central symbol of the block and then step the block forward
|
|
! by one symbol.
|
|
!
|
|
sbits3=sbits
|
|
!goto 100
|
|
nbit=13 ! number of decoded bits to be derived from nbit+1 symbols
|
|
numseq=2**nbit
|
|
il=(nbit+1)/2
|
|
ih=231-nbit/2
|
|
do isym=il,ih
|
|
rmax=-1e32
|
|
b=0
|
|
do iseq=0,numseq-1
|
|
do i=1,nbit
|
|
b(i)=merge(1,0,iand(iseq,2**(nbit-i))>0)
|
|
enddo
|
|
b(1:nbit)=2*b(1:nbit)-1
|
|
i1=isym-(nbit+1)/2
|
|
csum=cs(i1)
|
|
do i=1,nbit
|
|
bb=1
|
|
do m=1,i
|
|
bb=bb*b(m)
|
|
enddo
|
|
csum=csum+bb*cs(i1+i)
|
|
enddo
|
|
! ps(iseq)=abs(csum)**2
|
|
ps(iseq)=abs(csum)
|
|
if(ps(iseq).gt.rmax) then
|
|
bbest=b
|
|
rmax=ps(iseq)
|
|
endif
|
|
enddo
|
|
if(isym.eq.il) then
|
|
do i=1,isym-1
|
|
call getmetric(2**(nbit-i),ps,numseq,xmet)
|
|
sbits3(i)=-xmet
|
|
enddo
|
|
endif
|
|
call getmetric(2**((nbit-1)/2),ps,numseq,xmet)
|
|
sbits3(isym)=-xmet
|
|
if(isym.eq.ih) then
|
|
do i=ih+1,231
|
|
call getmetric(2**(231-i),ps,numseq,xmet)
|
|
sbits3(i)=-xmet
|
|
enddo
|
|
endif
|
|
enddo
|
|
100 continue
|
|
rxdata(1:100)=sbits3(1:100)
|
|
rxdata(101:200)=sbits3(132:231);
|
|
rxav=sum(rxdata(1:200))/200.0
|
|
rx2av=sum(rxdata(1:200)*rxdata(1:200))/200.0
|
|
rxsig=sqrt(rx2av-rxav*rxav)
|
|
rxdata=rxdata/rxsig
|
|
sigma=0.90
|
|
llr(201:204)=-5.0
|
|
llr(1:200)=2*rxdata/(sigma*sigma)
|
|
apmask=0
|
|
apmask(201:204)=1
|
|
max_iterations=40
|
|
ifer=0
|
|
call bpdecode204(llr,apmask,max_iterations,decoded,cw,nharderror,niterations)
|
|
nhardmin=-1
|
|
if(nharderror.lt.0) call osd204(llr,apmask,5,decoded,cw,nhardmin,dmin)
|
|
if(sum(decoded).eq.0) cycle
|
|
if(nhardmin.ge.0 .or. nharderror.ge.0) then
|
|
idat=0
|
|
write(dmsg,'(68i1)') decoded
|
|
read(dmsg(1:50),'(6b8.8,b2.2)') idat(1:7)
|
|
idat(7)=idat(7)*64
|
|
read(dmsg(51:64),'(b14.14)') ndec_crc
|
|
ncalc_crc=iand(crc14(c_loc(idat),9),z'FFFF')
|
|
nbadcrc=1
|
|
if(ncalc_crc .eq. ndec_crc) nbadcrc=0
|
|
else
|
|
cycle
|
|
endif
|
|
if( nbadcrc.eq.0 ) then
|
|
write(cbits,1200) decoded(1:50)
|
|
1200 format(50i1)
|
|
read(cbits,1202) idat
|
|
1202 format(8b8,b4)
|
|
idat(7)=ishft(idat(7),6)
|
|
call wqdecode(idat,message,itype)
|
|
idupe=0
|
|
do i=1,ndecodes
|
|
if(decodes(i).eq.message) idupe=1
|
|
enddo
|
|
if(idupe.eq.1) goto 888
|
|
ndecodes=ndecodes+1
|
|
decodes(ndecodes)=message
|
|
nsnr=nint(xsnr)
|
|
freq=fMHz + 1.d-6*(fc1+fbest)
|
|
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,ijitter,nharderror,nhardmin
|
|
1212 format(a4,i4,f5.1,f11.6,i3,2x,a22,a1,i5,i5,i5,i5,i5)
|
|
goto 888
|
|
endif
|
|
888 continue
|
|
enddo !candidate list
|
|
enddo !files
|
|
|
|
write(*,1120)
|
|
1120 format("<DecodeFinished>")
|
|
|
|
999 end program wsprdpskd
|
|
|
|
subroutine getmetric(ib,ps,ns,xmet)
|
|
real ps(0:ns-1)
|
|
xm1=-1e32
|
|
xm0=-1e32
|
|
do i=0,ns-1
|
|
if( iand(i/ib,1) .eq. 1 .and. ps(i) .gt. xm1 ) then
|
|
xm1=ps(i)
|
|
endif
|
|
if( iand(i/ib,1) .eq. 0 .and. ps(i) .gt. xm0 ) then
|
|
xm0=ps(i)
|
|
endif
|
|
enddo
|
|
xmet=xm1-xm0
|
|
return
|
|
end subroutine getmetric
|
|
|
|
subroutine getmetric3(ib,ps,ns,xmet)
|
|
real ps(0:ns-1)
|
|
xm1=0
|
|
xm0=0
|
|
do i=0,ns-1
|
|
if( iand(i/ib,1) .eq. 1 ) then
|
|
xm1=xm1+ps(i)
|
|
endif
|
|
if( iand(i/ib,1) .eq. 0 ) then
|
|
xm0=xm0+ps(i)
|
|
endif
|
|
enddo
|
|
xmet=xm1-xm0
|
|
return
|
|
end subroutine getmetric3
|
|
|
|
subroutine dsdpsk(ci,f0,co)
|
|
parameter(NI=240*200,NH=NI/2,NO=NI/20) ! downsample from 200 samples per symbol to 10
|
|
complex ci(0:NI-1),ct(0:NI-1)
|
|
complex co(0:NO-1)
|
|
|
|
pi=4.0*atan(1.0)
|
|
fs=12000.0/30.0
|
|
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)
|
|
|
|
dt=20/fs
|
|
beta=1.0
|
|
tt=10*dt
|
|
baud=1/tt
|
|
bw=(1+beta)*baud/2.0
|
|
bf=(1-beta)*baud/2.0
|
|
iw=bw/df
|
|
if=bf/df
|
|
co=0.0
|
|
co(0)=ct(0)
|
|
do i=1,iw
|
|
filt=((1.0+cos(pi*(i-if)/(iw-if)))/2.0)**0.5
|
|
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 dsdpsk
|
|
|
|
subroutine getcandidate2(c,npts,fs,fa,fb,ncand,candidates)
|
|
parameter(NDAT=200,NFFT1=120*12000/30,NH1=NFFT1/2,NFFT2=120*12000/300,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)/20.0)**2)
|
|
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))-30.0
|
|
endif
|
|
enddo
|
|
! do i=1,ncand
|
|
! write(*,*) i,candidates(i,1),candidates(i,2)
|
|
! enddo
|
|
return
|
|
end subroutine getcandidate2
|
|
|
|
subroutine wsprdpsk_downsample(iwave,c)
|
|
|
|
! Input: i*2 data in iwave() at sample rate 12000 Hz
|
|
! Output: Complex data in c(), sampled at 400 Hz
|
|
|
|
include 'wsprdpsk_params.f90'
|
|
parameter (NMAX=120*12000,NFFT2=NMAX/30)
|
|
integer*2 iwave(NMAX)
|
|
complex c(0:NMAX/30-1)
|
|
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/30-1)
|
|
return
|
|
end subroutine wsprdpsk_downsample
|
|
|