mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-08-26 08:06:36 -04:00
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6922 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
459 lines
14 KiB
Fortran
459 lines
14 KiB
Fortran
subroutine detectmsk32(cbig,n,mycall,partnercall,lines,nmessages,nutc,ntol,t00)
|
|
use timer_module, only: timer
|
|
|
|
parameter (NSPM=192, NPTS=3*NSPM, MAXSTEPS=7500, NFFT=3*NSPM, MAXCAND=40)
|
|
character*4 rpt(0:31)
|
|
character*6 mycall,partnercall
|
|
character*22 msg,hashmsg,msgreceived,allmessages(20)
|
|
character*80 lines(100)
|
|
complex cbig(n)
|
|
complex cdat(NPTS) !Analytic signal
|
|
complex cdat2(NPTS)
|
|
complex c(NSPM)
|
|
complex ctmp(NFFT)
|
|
complex cb(42) !Complex waveform for sync word
|
|
complex cbr(42) !Complex waveform for reversed sync word
|
|
complex cfac,cca,ccb
|
|
complex cc(NPTS)
|
|
complex ccr(NPTS)
|
|
complex cc1(NPTS)
|
|
complex cc2(NPTS)
|
|
complex ccr1(NPTS)
|
|
complex ccr2(NPTS)
|
|
complex bb(6)
|
|
integer s8(8),s8r(8),hardbits(32)
|
|
integer, dimension(1) :: iloc
|
|
integer ihammd(0:4096-1)
|
|
integer indices(MAXSTEPS)
|
|
integer ipeaks(10)
|
|
integer ig24(0:4096-1)
|
|
integer likelymessages(0:31)
|
|
logical qsocontext
|
|
logical ismask(NFFT)
|
|
real cbi(42),cbq(42)
|
|
real cd(0:4095)
|
|
real detmet(-2:MAXSTEPS+3)
|
|
real detfer(MAXSTEPS)
|
|
real rcw(12)
|
|
real dd(NPTS)
|
|
real ddr(NPTS)
|
|
real ferrs(MAXCAND)
|
|
real pp(12) !Half-sine pulse shape
|
|
real snrs(MAXCAND)
|
|
real times(MAXCAND)
|
|
real tonespec(NFFT)
|
|
real*8 dt, df, fs, pi, twopi
|
|
real softbits(32)
|
|
logical first
|
|
data first/.true./
|
|
data s8/0,1,1,1,0,0,1,0/
|
|
data s8r/1,0,1,1,0,0,0,1/
|
|
data rpt /'-04 ','-02 ','+00 ','+02 ','+04 ','+06 ','+08 ','+10 ','+12 ', &
|
|
'+14 ','+16 ','+18 ','+20 ','+22 ','+24 ', &
|
|
'R-04','R-02','R+00','R+02','R+04','R+06','R+08','R+10','R+12', &
|
|
'R+14','R+16','R+18','R+20','R+22','R+24', &
|
|
'RRR ','73 '/
|
|
save df,first,cb,cbr,fs,pi,twopi,dt,s8,rcw,pp,nmatchedfilter,ig24
|
|
|
|
if(first) then
|
|
nmatchedfilter=1
|
|
! define half-sine pulse and raised-cosine edge window
|
|
pi=4d0*datan(1d0)
|
|
twopi=8d0*datan(1d0)
|
|
fs=12000.0
|
|
dt=1.0/fs
|
|
df=fs/NFFT
|
|
|
|
do i=1,12
|
|
angle=(i-1)*pi/12.0
|
|
pp(i)=sin(angle)
|
|
rcw(i)=(1-cos(angle))/2
|
|
enddo
|
|
|
|
! define the sync word waveforms
|
|
s8=2*s8-1
|
|
cbq(1:6)=pp(7:12)*s8(1)
|
|
cbq(7:18)=pp*s8(3)
|
|
cbq(19:30)=pp*s8(5)
|
|
cbq(31:42)=pp*s8(7)
|
|
cbi(1:12)=pp*s8(2)
|
|
cbi(13:24)=pp*s8(4)
|
|
cbi(25:36)=pp*s8(6)
|
|
cbi(37:42)=pp(1:6)*s8(8)
|
|
cb=cmplx(cbi,cbq)
|
|
s8r=2*s8r-1
|
|
cbq(1:6)=pp(7:12)*s8r(1)
|
|
cbq(7:18)=pp*s8r(3)
|
|
cbq(19:30)=pp*s8r(5)
|
|
cbq(31:42)=pp*s8r(7)
|
|
cbi(1:12)=pp*s8r(2)
|
|
cbi(13:24)=pp*s8r(4)
|
|
cbi(25:36)=pp*s8r(6)
|
|
cbi(37:42)=pp(1:6)*s8r(8)
|
|
cbr=cmplx(cbi,cbq)
|
|
|
|
call golay24_table(ig24)
|
|
|
|
first=.false.
|
|
endif
|
|
|
|
! Define the 32 likely messages
|
|
do irpt=0,31
|
|
hashmsg=trim(mycall)//' '//trim(partnercall)//' '//rpt(irpt)
|
|
call fmtmsg(hashmsg,iz)
|
|
call hash(hashmsg,22,ihash)
|
|
ihash=iand(ihash,127)
|
|
ig=32*ihash + irpt
|
|
likelymessages(irpt)=ig
|
|
! write(*,*) irpt,hashmsg,ig,ig24(ig)
|
|
enddo
|
|
qsocontext=.false.
|
|
|
|
! Fill the detmet, detferr arrays
|
|
nstepsize=48 ! 4ms steps
|
|
nstep=(n-NPTS)/nstepsize
|
|
detmet=0
|
|
detmax=-999.99
|
|
detfer=-999.99
|
|
do istp=1,nstep
|
|
ns=1+nstepsize*(istp-1)
|
|
ne=ns+NPTS-1
|
|
if( ne .gt. n ) exit
|
|
ctmp=cmplx(0.0,0.0)
|
|
ctmp(1:NPTS)=cbig(ns:ne)
|
|
|
|
! Coarse carrier frequency sync - seek tones at 2000 Hz and 4000 Hz in
|
|
! squared signal spectrum.
|
|
! search range for coarse frequency error is +/- 100 Hz
|
|
|
|
ctmp=ctmp**2
|
|
ctmp(1:12)=ctmp(1:12)*rcw
|
|
ctmp(NPTS-11:NPTS)=ctmp(NPTS-11:NPTS)*rcw(12:1:-1)
|
|
call four2a(ctmp,NFFT,1,-1,1)
|
|
tonespec=abs(ctmp)**2
|
|
|
|
ihlo=(4000-2*ntol)/df+1
|
|
ihhi=(4000+2*ntol)/df+1
|
|
ismask=.false.
|
|
ismask(ihlo:ihhi)=.true. ! high tone search window
|
|
iloc=maxloc(tonespec,ismask)
|
|
ihpk=iloc(1)
|
|
deltah=-real( (ctmp(ihpk-1)-ctmp(ihpk+1)) / (2*ctmp(ihpk)-ctmp(ihpk-1)-ctmp(ihpk+1)) )
|
|
ah=tonespec(ihpk)
|
|
illo=(2000-2*ntol)/df+1
|
|
ilhi=(2000+2*ntol)/df+1
|
|
ismask=.false.
|
|
ismask(illo:ilhi)=.true. ! window for low tone
|
|
iloc=maxloc(tonespec,ismask)
|
|
ilpk=iloc(1)
|
|
deltal=-real( (ctmp(ilpk-1)-ctmp(ilpk+1)) / (2*ctmp(ilpk)-ctmp(ilpk-1)-ctmp(ilpk+1)) )
|
|
al=tonespec(ilpk)
|
|
fdiff=(ihpk+deltah-ilpk-deltal)*df
|
|
i2000=2000/df+1
|
|
i4000=4000/df+1
|
|
ferrh=(ihpk+deltah-i4000)*df/2.0
|
|
ferrl=(ilpk+deltal-i2000)*df/2.0
|
|
if( ah .ge. al ) then
|
|
ferr=ferrh
|
|
else
|
|
ferr=ferrl
|
|
endif
|
|
detmet(istp)=max(ah,al)
|
|
detfer(istp)=ferr
|
|
! write(*,*) istp,ilpk,ihpk,ah,al
|
|
enddo ! end of detection-metric and frequency error estimation loop
|
|
|
|
call indexx(detmet(1:nstep),nstep,indices) !find median of detection metric vector
|
|
! xmed=detmet(indices(nstep/2))
|
|
xmed=detmet(indices(nstep/4))
|
|
detmet=detmet/xmed ! noise floor of detection metric is 1.0
|
|
ndet=0
|
|
|
|
!do i=1,nstep
|
|
!write(77,*) i,detmet(i),detfer(i)
|
|
!enddo
|
|
|
|
do ip=1,MAXCAND ! use something like the "clean" algorithm to find candidates
|
|
iloc=maxloc(detmet(1:nstep))
|
|
il=iloc(1)
|
|
if( (detmet(il) .lt. 4.2) ) exit
|
|
if( abs(detfer(il)) .le. ntol ) then
|
|
ndet=ndet+1
|
|
times(ndet)=((il-1)*nstepsize+NPTS/2)*dt
|
|
ferrs(ndet)=detfer(il)
|
|
snrs(ndet)=12.0*log10(detmet(il)-1)/2-8.0
|
|
endif
|
|
detmet(max(1,il-3):min(nstep,il+3))=0.0
|
|
! detmet(il)=0.0
|
|
enddo
|
|
|
|
! do ip=1,ndet
|
|
! write(*,*) ip,times(ip),snrs(ip),ferrs(ip)
|
|
! enddo
|
|
|
|
nmessages=0
|
|
allmessages=char(0)
|
|
lines=char(0)
|
|
|
|
imsgbest=-1
|
|
nbadsyncbest=99
|
|
nhammdbest=99
|
|
cdbest=1e32
|
|
cdratbest=0.0
|
|
|
|
do ip=1,ndet !run through the candidates and try to sync/demod/decode
|
|
imid=times(ip)*fs
|
|
if( imid .lt. NPTS/2 ) imid=NPTS/2
|
|
if( imid .gt. n-NPTS/2 ) imid=n-NPTS/2
|
|
t0=times(ip) + t00
|
|
cdat=cbig(imid-NPTS/2+1:imid+NPTS/2)
|
|
ferr=ferrs(ip)
|
|
nsnr=2*nint(snrs(ip)/2.0)
|
|
if( nsnr .lt. -4 ) nsnr=-4
|
|
if( nsnr .gt. 24 ) nsnr=24
|
|
|
|
! remove coarse freq error - should now be within a few Hz
|
|
call tweak1(cdat,NPTS,-(1500+ferr),cdat)
|
|
|
|
! attempt frame synchronization
|
|
! correlate with sync word waveforms
|
|
ccr=0
|
|
ccr1=0
|
|
ccr2=0
|
|
do i=1,NPTS-(32*6+41)
|
|
ccr1(i)=sum(cdat(i:i+41)*conjg(cbr))
|
|
ccr2(i)=sum(cdat(i+32*6:i+32*6+41)*conjg(cbr))
|
|
enddo
|
|
ccr=ccr1+ccr2
|
|
ddr=abs(ccr1)*abs(ccr2)
|
|
crmax=maxval(abs(ccr))
|
|
|
|
! Find 6 largest peaks
|
|
do ipk=1,6
|
|
iloc=maxloc(abs(ccr))
|
|
ic1=iloc(1)
|
|
iloc=maxloc(ddr)
|
|
ic2=iloc(1)
|
|
ipeaks(ipk)=ic1
|
|
ccr(max(1,ic1-7):min(NPTS-32*6-41,ic1+7))=0.0
|
|
enddo
|
|
|
|
do ipk=1,3
|
|
|
|
! we want ic to be the index of the first sample of the frame
|
|
ic0=ipeaks(ipk)
|
|
|
|
! fine adjustment of sync index
|
|
do i=1,6
|
|
if( ic0+11+NSPM .le. NPTS ) then
|
|
bb(i) = sum( ( cdat(ic0+i-1+6:ic0+i-1+6+NSPM:6) * conjg( cdat(ic0+i-1:ic0+i-1+NSPM:6) ) )**2 )
|
|
else
|
|
bb(i) = sum( ( cdat(ic0+i-1+6:NPTS:6) * conjg( cdat(ic0+i-1:NPTS-6:6) ) )**2 )
|
|
endif
|
|
enddo
|
|
iloc=maxloc(abs(bb))
|
|
ibb=iloc(1)
|
|
bba=abs(bb(ibb))
|
|
bbp=atan2(-imag(bb(ibb)),-real(bb(ibb)))/(2*twopi*6*dt)
|
|
if( ibb .le. 3 ) ibb=ibb-1
|
|
if( ibb .gt. 3 ) ibb=ibb-7
|
|
|
|
do id=1,1 ! slicer dither.
|
|
if( id .eq. 1 ) is=0
|
|
if( id .eq. 2 ) is=-1
|
|
if( id .eq. 3 ) is=1
|
|
|
|
! Adjust frame index to place peak of bb at desired lag
|
|
ic=ic0+ibb+is
|
|
if( ic .lt. 1 ) ic=ic+NSPM
|
|
|
|
! Estimate fine frequency error.
|
|
cca=sum(cdat(ic:ic+41)*conjg(cb))
|
|
if( ic+32*6+41 .le. NPTS ) then
|
|
ccb=sum(cdat(ic+32*6:ic+32*6+41)*conjg(cb))
|
|
cfac=ccb*conjg(cca)
|
|
ferr2=atan2(imag(cfac),real(cfac))/(twopi*32*6*dt)
|
|
else
|
|
ccb=sum(cdat(ic-32*6:ic-32*6+41)*conjg(cb))
|
|
cfac=cca*conjg(ccb)
|
|
ferr2=atan2(imag(cfac),real(cfac))/(twopi*32*6*dt)
|
|
endif
|
|
|
|
! Final estimate of the carrier frequency - returned to the calling program
|
|
fest=1500+ferr+ferr2
|
|
|
|
do idf=0,6 ! frequency jitter
|
|
if( idf .eq. 0 ) then
|
|
deltaf=0.0
|
|
elseif( mod(idf,2) .eq. 0 ) then
|
|
deltaf=2*idf
|
|
else
|
|
deltaf=-2*(idf+1)
|
|
endif
|
|
|
|
! Remove fine frequency error
|
|
call tweak1(cdat,NPTS,-(ferr2+deltaf),cdat2)
|
|
|
|
! place the beginning of frame at index NSPM+1
|
|
cdat2=cshift(cdat2,ic-(NSPM+1))
|
|
|
|
do iav=1,4 ! Frame averaging patterns
|
|
if( iav .eq. 1 ) then
|
|
c=cdat2(NSPM+1:2*NSPM)
|
|
elseif( iav .eq. 2 ) then
|
|
c=cdat2(1:NSPM)+cdat2(NSPM+1:2*NSPM)
|
|
elseif( iav .eq. 3 ) then
|
|
c=cdat2(NSPM+1:2*NSPM)+cdat2(2*NSPM+1:3*NSPM)
|
|
elseif( iav .eq. 4 ) then
|
|
c=cdat2(1:NSPM)+cdat2(NSPM+1:2*NSPM)+cdat2(2*NSPM+1:3*NSPM)
|
|
endif
|
|
|
|
! Estimate final frequency error and carrier phase.
|
|
cca=sum(c(1:1+41)*conjg(cb))
|
|
phase0=atan2(imag(cca),real(cca))
|
|
|
|
do ipha=1,3
|
|
if( ipha.eq.2 ) phase0=phase0-20*pi/180.0
|
|
if( ipha.eq.3 ) phase0=phase0+20*pi/180.0
|
|
|
|
! Remove phase error - want constellation rotated so that sample points lie on I/Q axes
|
|
cfac=cmplx(cos(phase0),sin(phase0))
|
|
c=c*conjg(cfac)
|
|
|
|
if( nmatchedfilter .eq. 0 ) then
|
|
do i=1, 16
|
|
softbits(2*i-1)=imag(c(1+(i-1)*12))
|
|
softbits(2*i)=real(c(7+(i-1)*12))
|
|
enddo
|
|
else ! matched filter
|
|
softbits(1)=sum(imag(c(1:6))*pp(7:12))+sum(imag(c(NSPM-5:NSPM))*pp(1:6))
|
|
softbits(2)=sum(real(c(1:12))*pp)
|
|
do i=2,16
|
|
softbits(2*i-1)=sum(imag(c(1+(i-1)*12-6:1+(i-1)*12+5))*pp)
|
|
softbits(2*i)=sum(real(c(7+(i-1)*12-6:7+(i-1)*12+5))*pp)
|
|
enddo
|
|
endif
|
|
|
|
hardbits=0 ! use sync word hard error weight to decide whether to send to decoder
|
|
do i=1, 32
|
|
if( softbits(i) .ge. 0.0 ) then
|
|
hardbits(i)=1
|
|
endif
|
|
enddo
|
|
nbadsync1=(8-sum( (2*hardbits(1:8)-1)*s8r ) )/2
|
|
nbadsync=nbadsync1
|
|
if( nbadsync .gt. 3 ) cycle
|
|
|
|
! normalize the softsymbols before submitting to decoder
|
|
sav=sum(softbits)/32
|
|
s2av=sum(softbits*softbits)/32
|
|
ssig=sqrt(s2av-sav*sav)
|
|
softbits=softbits/ssig
|
|
|
|
if( qsocontext ) then ! search only 32 likely messages.
|
|
cd=1e6
|
|
ihammd=99
|
|
do i=0,31
|
|
ncw=ig24(likelymessages(i))
|
|
cd(i)=0.0
|
|
ihammd(i)=0
|
|
do ii=1,24
|
|
ib=iand(1,ishft(ncw,1-ii))
|
|
ib=2*ib-1
|
|
if( ib*softbits(ii+8) .lt. 0 ) then
|
|
cd(i)=cd(i)+abs(softbits(ii+8))
|
|
ihammd(i)=ihammd(i)+1
|
|
endif
|
|
enddo
|
|
enddo
|
|
else ! exhaustive decoder, look at every codeword.
|
|
cd=1e6
|
|
ihammd=99
|
|
do i=0,4096-1
|
|
ncw=ig24(i)
|
|
cd(i)=0.0
|
|
ihammd(i)=0
|
|
do ii=1,24
|
|
ib=iand(1,ishft(ncw,1-ii))
|
|
ib=2*ib-1
|
|
if( ib*softbits(ii+8) .lt. 0 ) then
|
|
cd(i)=cd(i)+abs(softbits(ii+8))
|
|
ihammd(i)=ihammd(i)+1
|
|
endif
|
|
enddo
|
|
enddo
|
|
endif
|
|
cdm=minval(cd)
|
|
iloc=minloc(cd)
|
|
imsg=iloc(1)-1
|
|
cd(imsg)=1e6
|
|
cdm2=minval(cd)
|
|
iloc=minloc(cd)
|
|
imsg2=iloc(1)-1
|
|
cdrat=cdm2/(cdm+0.001)
|
|
cdrat2=cdm/(cdm2+0.0001)
|
|
if( (cdm .lt. cdbest) .or. ((cdm .eq. cdbest) .and. (ihammd(imsg) .lt. nhammdbest)) ) then
|
|
cdratbest = cdrat
|
|
cdrat2best = cdrat2
|
|
cdbest = cdm
|
|
imsgbest = imsg
|
|
imsg2best = imsg2
|
|
iavbest = iav
|
|
ipbest = ip
|
|
ipkbest = ipk
|
|
idfbest = idf
|
|
idbest = id
|
|
iphabest = ipha
|
|
nbadsyncbest = nbadsync
|
|
nhammdbest = ihammd(imsg)
|
|
if( ( nhammdbest .eq. 0 ) .and. (cdbest .eq. 0.0) .and. (cdratbest .gt. 2000.0) ) goto 999
|
|
endif
|
|
enddo ! phase loop
|
|
enddo ! frame averaging loop
|
|
enddo ! frequency dithering loop
|
|
enddo ! slicer dither loop
|
|
enddo ! time-sync correlation-peak loop
|
|
enddo ! candidate loop
|
|
999 continue
|
|
msgreceived=' '
|
|
if( imsgbest .gt. 0 ) then
|
|
if( ( nhammdbest+nbadsyncbest .le. 4 ) .and. cdratbest .gt. 10.0 ) then
|
|
if( qsocontext ) then
|
|
nrxrpt=iand(likelymessages(imsgbest),31)
|
|
nrxhash=(likelymessages(imsgbest)-nrxrpt)/32
|
|
imessage=likelymessages(imsgbest)
|
|
else
|
|
nrxrpt=iand(imsgbest,31)
|
|
nrxhash=(imsgbest-nrxrpt)/32
|
|
imessage=imsgbest
|
|
endif
|
|
|
|
! See if this message has a hash that is expected for a message sent to mycall by partnercall
|
|
hashmsg=trim(mycall)//' '//trim(partnercall)//' '//rpt(nrxrpt)
|
|
call fmtmsg(hashmsg,iz)
|
|
call hash(hashmsg,22,ihash)
|
|
ihash=iand(ihash,127)
|
|
|
|
if(nrxhash.eq.ihash .or. t00.gt.0.0) then
|
|
nmessages=1
|
|
if(nrxhash.eq.ihash) then
|
|
write(msgreceived,'(a1,a,1x,a,a1,1x,a4)') "<",trim(mycall), &
|
|
trim(partnercall),">",rpt(nrxrpt)
|
|
write(lines(nmessages),1020) nutc,nsnr,t0,nint(fest),msgreceived
|
|
1020 format(i6.6,i4,f5.1,i5,' & ',a22)
|
|
endif
|
|
if(nrxhash.ne.ihash .and. t00.gt.0.0 .and. nsnr.gt.-4) then
|
|
write(msgreceived,'(a5,1x,a4)') "<...>",rpt(nrxrpt)
|
|
write(lines(nmessages),1020) nutc,nsnr,t0,nint(fest),msgreceived
|
|
endif
|
|
|
|
! write(*,1022) nutc,ipbest,times(ipbest),snrs(ipbest),fest,nrxrpt,nrxhash, &
|
|
! rpt(nrxrpt),imessage,ig24(imessage),nhammdbest, &
|
|
! cdbest,cdratbest,cdrat2best,nbadsyncbest,ipkbest,idbest,idfbest,iavbest,iphabest
|
|
!1022 format(i4.4,2x,i4,f8.3,f8.2,f8.2,i6,i6,a6,i8,i10,i4,f8.3,f8.2,f8.2,i5,i5,i5,i5,i5,i5)
|
|
endif
|
|
endif
|
|
endif
|
|
return
|
|
end subroutine detectmsk32
|