mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-18 18:12:12 -05:00
07951f1a18
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6927 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
147 lines
3.2 KiB
Fortran
147 lines
3.2 KiB
Fortran
subroutine qra64a(dd,nf1,nf2,nfqso,ntol,mycall_12,sync,nsnr,dtx,nfreq, &
|
|
decoded,nft)
|
|
|
|
use packjt
|
|
parameter (NFFT=2*6912,NH=NFFT/2,NZ=5760)
|
|
character decoded*22,mycall_12*12,mycall*6
|
|
logical ltext
|
|
integer icos7(0:6)
|
|
integer ipk(1)
|
|
integer jpk(1)
|
|
integer dat4(12)
|
|
real dd(60*12000)
|
|
real s(NZ)
|
|
real savg(NZ)
|
|
real blue(0:25)
|
|
real red0(NZ)
|
|
real red(NZ)
|
|
real x(NFFT)
|
|
complex cx(0:NH)
|
|
equivalence (x,cx)
|
|
data icos7/2,5,6,0,4,1,3/ !Costas 7x7 pattern
|
|
common/qra64com/ss(NZ,194),s3(0:63,1:63),ccf(NZ,0:25)
|
|
save
|
|
|
|
decoded=' '
|
|
nft=99
|
|
nsnr=-30
|
|
nsps=6912
|
|
istep=nsps/2
|
|
nsteps=52*12000/istep - 2
|
|
ia=1-istep
|
|
savg=0.
|
|
df=12000.0/NFFT
|
|
do j=1,nsteps
|
|
ia=ia+istep
|
|
ib=ia+nsps-1
|
|
x(1:nsps)=1.2e-4*dd(ia:ib)
|
|
x(nsps+1:)=0.0
|
|
call four2a(x,nfft,1,-1,0) !r2c FFT
|
|
do i=1,NZ
|
|
s(i)=real(cx(i))**2 + aimag(cx(i))**2
|
|
enddo
|
|
ss(1:NZ,j)=s
|
|
savg=savg+s
|
|
enddo
|
|
savg=savg/nsteps
|
|
|
|
fa=max(nf1,nfqso-ntol)
|
|
fb=min(nf2,nfqso+ntol)
|
|
ia=nint(fa/df)
|
|
ib=nint(fb/df)
|
|
call pctile(savg(ia),ib-ia+1,45,base)
|
|
savg=savg/base - 1.0
|
|
ss=ss/base
|
|
|
|
red0=0.
|
|
fac=1.0/sqrt(21.0)
|
|
sync=0.
|
|
do if0=ia,ib
|
|
red0(if0)=0.
|
|
do j=0,25
|
|
t=-3.0
|
|
do n=0,6
|
|
i=if0 + 2*icos7(n)
|
|
t=t + ss(i,1+2*n+j) + ss(i,1+2*n+j+78) + ss(i,1+2*n+j+154)
|
|
enddo
|
|
ccf(if0,j)=fac*t
|
|
if(ccf(if0,j).gt.red0(if0)) then
|
|
red0(if0)=ccf(if0,j)
|
|
if(red0(if0).gt.sync) then
|
|
sync=red0(if0)
|
|
f0=if0*df
|
|
dtx=j*istep/12000.0 - 1.0
|
|
i0=if0
|
|
j0=j
|
|
endif
|
|
endif
|
|
enddo
|
|
enddo
|
|
|
|
! red(ia:ib)=0.
|
|
! rewind 73
|
|
! do i=ia+3,ib-3
|
|
! r1=red0(i)
|
|
! red0(i)=0.
|
|
! r0=max(red0(i-3),red0(i-2),red0(i+2),red0(i+3))
|
|
! red0(i)=r1
|
|
! red(i)=max(0.0,r1-r0)
|
|
! write(73,3001) i*df,red(i),red0(i),r0
|
|
!3001 format(4f12.3)
|
|
! enddo
|
|
! flush(73)
|
|
|
|
red0=red0-4.0
|
|
write(17) ia,ib,red0(ia:ib)
|
|
close(17)
|
|
|
|
if0=nint(f0/df)
|
|
nfreq=nint(f0)
|
|
blue(0:25)=ccf(if0,0:25)
|
|
jpk=maxloc(blue)
|
|
xpk=jpk(1) + 1.0
|
|
call slope(blue,26,xpk)
|
|
|
|
! Insist on at least 10 correct hard decisions in the 21 Costas bins.
|
|
nhard=0
|
|
do n=0,6
|
|
ipk=maxloc(ss(i0:i0+63,1+j0+2*n)) - 1
|
|
i=abs(ipk(1)-2*icos7(n))
|
|
if(i.le.1) nhard=nhard+1
|
|
|
|
ipk=maxloc(ss(i0:i0+63,1+j0+2*n+78)) - 1
|
|
i=abs(ipk(1)-2*icos7(n))
|
|
if(i.le.1) nhard=nhard+1
|
|
|
|
ipk=maxloc(ss(i0:i0+63,1+j0+2*n+154)) - 1
|
|
i=abs(ipk(1)-2*icos7(n))
|
|
if(i.le.1) nhard=nhard+1
|
|
enddo
|
|
! print*,'a',nhard,nhard,nhard
|
|
if(nhard.lt.6) go to 900
|
|
|
|
do i=0,63
|
|
k=i0 + 2*i
|
|
jj=j0+13
|
|
do j=1,63
|
|
jj=jj+2
|
|
s3(i,j)=ss(k,jj)
|
|
if(j.eq.32) jj=jj+14 !Skip over the middle Costas array
|
|
enddo
|
|
enddo
|
|
|
|
if(sync.gt.1.0) nsnr=nint(10.0*log10(sync) - 38.0)
|
|
! if(sync.lt.12.8) go to 900 !### Temporary ###
|
|
|
|
mycall=mycall_12(1:6) !### May need fixing ###
|
|
call packcall(mycall,nmycall,ltext)
|
|
call qra64_dec(s3,nmycall,dat4,irc) !Attempt decoding
|
|
if(irc.ge.0) then
|
|
call unpackmsg(dat4,decoded) !Unpack the user message
|
|
call fmtmsg(decoded,iz)
|
|
nft=100 + irc
|
|
endif
|
|
|
|
900 return
|
|
end subroutine qra64a
|