mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2025-10-30 20:40:28 -04:00
117 lines
3.0 KiB
Fortran
117 lines
3.0 KiB
Fortran
subroutine get_ft4_bitmetrics(cd,bitmetrics,badsync)
|
|
|
|
include 'ft4_params.f90'
|
|
parameter (NSS=NSPS/NDOWN,NDMAX=NMAX/NDOWN)
|
|
complex cd(0:NN*NSS-1)
|
|
complex cs(0:3,NN)
|
|
complex csymb(NSS)
|
|
integer icos4a(0:3),icos4b(0:3),icos4c(0:3),icos4d(0:3)
|
|
integer graymap(0:3)
|
|
integer ip(1)
|
|
logical one(0:255,0:7) ! 256 4-symbol sequences, 8 bits
|
|
logical first
|
|
logical badsync
|
|
real bitmetrics(2*NN,3)
|
|
real s2(0:255)
|
|
real s4(0:3,NN)
|
|
|
|
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 graymap/0,1,3,2/
|
|
data first/.true./
|
|
save first,one
|
|
|
|
if(first) then
|
|
one=.false.
|
|
do i=0,255
|
|
do j=0,7
|
|
if(iand(i,2**j).ne.0) one(i,j)=.true.
|
|
enddo
|
|
enddo
|
|
first=.false.
|
|
endif
|
|
|
|
do k=1,NN
|
|
i1=(k-1)*NSS
|
|
csymb=cd(i1:i1+NSS-1)
|
|
call four2a(csymb,NSS,1,-1,1)
|
|
cs(0:3,k)=csymb(1:4)
|
|
s4(0:3,k)=abs(csymb(1:4))
|
|
enddo
|
|
|
|
! Sync quality check
|
|
is1=0
|
|
is2=0
|
|
is3=0
|
|
is4=0
|
|
badsync=.false.
|
|
ibmax=0
|
|
|
|
do k=1,4
|
|
ip=maxloc(s4(:,k))
|
|
if(icos4a(k-1).eq.(ip(1)-1)) is1=is1+1
|
|
ip=maxloc(s4(:,k+33))
|
|
if(icos4b(k-1).eq.(ip(1)-1)) is2=is2+1
|
|
ip=maxloc(s4(:,k+66))
|
|
if(icos4c(k-1).eq.(ip(1)-1)) is3=is3+1
|
|
ip=maxloc(s4(:,k+99))
|
|
if(icos4d(k-1).eq.(ip(1)-1)) is4=is4+1
|
|
enddo
|
|
nsync=is1+is2+is3+is4 !Number of correct hard sync symbols, 0-16
|
|
if(nsync .lt. 8) then
|
|
badsync=.true.
|
|
return
|
|
endif
|
|
|
|
do nseq=1,3 !Try coherent sequences of 1, 2, and 4 symbols
|
|
if(nseq.eq.1) nsym=1
|
|
if(nseq.eq.2) nsym=2
|
|
if(nseq.eq.3) nsym=4
|
|
nt=2**(2*nsym)
|
|
do ks=1,NN-nsym+1,nsym !87+16=103 symbols.
|
|
amax=-1.0
|
|
do i=0,nt-1
|
|
i1=i/64
|
|
i2=iand(i,63)/16
|
|
i3=iand(i,15)/4
|
|
i4=iand(i,3)
|
|
if(nsym.eq.1) then
|
|
s2(i)=abs(cs(graymap(i4),ks))
|
|
elseif(nsym.eq.2) then
|
|
s2(i)=abs(cs(graymap(i3),ks)+cs(graymap(i4),ks+1))
|
|
elseif(nsym.eq.4) then
|
|
s2(i)=abs(cs(graymap(i1),ks ) + &
|
|
cs(graymap(i2),ks+1) + &
|
|
cs(graymap(i3),ks+2) + &
|
|
cs(graymap(i4),ks+3) &
|
|
)
|
|
else
|
|
print*,"Error - nsym must be 1, 2, or 4."
|
|
endif
|
|
enddo
|
|
ipt=1+(ks-1)*2
|
|
if(nsym.eq.1) ibmax=1
|
|
if(nsym.eq.2) ibmax=3
|
|
if(nsym.eq.4) ibmax=7
|
|
do ib=0,ibmax
|
|
bm=maxval(s2(0:nt-1),one(0:nt-1,ibmax-ib)) - &
|
|
maxval(s2(0:nt-1),.not.one(0:nt-1,ibmax-ib))
|
|
if(ipt+ib.gt.2*NN) cycle
|
|
bitmetrics(ipt+ib,nseq)=bm
|
|
enddo
|
|
enddo
|
|
enddo
|
|
|
|
bitmetrics(205:206,2)=bitmetrics(205:206,1)
|
|
bitmetrics(201:204,3)=bitmetrics(201:204,2)
|
|
bitmetrics(205:206,3)=bitmetrics(205:206,1)
|
|
|
|
call normalizebmet(bitmetrics(:,1),2*NN)
|
|
call normalizebmet(bitmetrics(:,2),2*NN)
|
|
call normalizebmet(bitmetrics(:,3),2*NN)
|
|
return
|
|
|
|
end subroutine get_ft4_bitmetrics
|