mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-26 14:18:38 -05:00
124 lines
3.2 KiB
Fortran
124 lines
3.2 KiB
Fortran
subroutine get_fst240_bitmetrics(cd,nss,hmod,nmax,bitmetrics,s4,badsync)
|
|
|
|
include 'fst240_params.f90'
|
|
complex cd(0:NN*nss-1)
|
|
complex cs(0:3,NN)
|
|
complex csymb(nss)
|
|
complex, allocatable, save :: c1(:,:) ! ideal waveforms, 20 samples per symbol, 4 tones
|
|
complex cp(0:3) ! accumulated phase shift over symbol types 0:3
|
|
complex csum,cterm
|
|
integer icos8(0:7)
|
|
integer graymap(0:3)
|
|
integer ip(1)
|
|
integer hmod
|
|
logical one(0:65535,0:15) ! 65536 8-symbol sequences, 16 bits
|
|
logical first
|
|
logical badsync
|
|
real bitmetrics(2*NN,4)
|
|
real s2(0:65535)
|
|
real s4(0:3,NN)
|
|
data icos8/0,1,3,2,1,0,2,3/
|
|
data graymap/0,1,3,2/
|
|
data first/.true./,nss0/-1/
|
|
save first,one,cp,nss0
|
|
|
|
if(nss.ne.nss0 .and. allocated(c1)) deallocate(c1)
|
|
if(first .or. nss.ne.nss0) then
|
|
allocate(c1(nss,0:3))
|
|
one=.false.
|
|
do i=0,65535
|
|
do j=0,15
|
|
if(iand(i,2**j).ne.0) one(i,j)=.true.
|
|
enddo
|
|
enddo
|
|
twopi=8.0*atan(1.0)
|
|
dphi=twopi*hmod/nss
|
|
do itone=0,3
|
|
dp=(itone-1.5)*dphi
|
|
phi=0.0
|
|
do j=1,nss
|
|
c1(j,itone)=cmplx(cos(phi),sin(phi))
|
|
phi=mod(phi+dp,twopi)
|
|
enddo
|
|
cp(itone)=cmplx(cos(phi),sin(phi))
|
|
enddo
|
|
first=.false.
|
|
endif
|
|
|
|
do k=1,NN
|
|
i1=(k-1)*NSS
|
|
csymb=cd(i1:i1+NSS-1)
|
|
do itone=0,3
|
|
cs(itone,k)=sum(csymb*conjg(c1(:,itone)))
|
|
enddo
|
|
s4(0:3,k)=abs(cs(0:3,k))
|
|
enddo
|
|
|
|
! Sync quality check
|
|
is1=0
|
|
is2=0
|
|
is3=0
|
|
badsync=.false.
|
|
ibmax=0
|
|
|
|
do k=1,8
|
|
ip=maxloc(s4(:,k))
|
|
if(icos8(k-1).eq.(ip(1)-1)) is1=is1+1
|
|
ip=maxloc(s4(:,k+38))
|
|
if(icos8(k-1).eq.(ip(1)-1)) is2=is2+1
|
|
ip=maxloc(s4(:,k+76))
|
|
if(icos8(k-1).eq.(ip(1)-1)) is3=is3+1
|
|
ip=maxloc(s4(:,k+114))
|
|
if(icos8(k-1).eq.(ip(1)-1)) is4=is4+1
|
|
ip=maxloc(s4(:,k+152))
|
|
if(icos8(k-1).eq.(ip(1)-1)) is5=is5+1
|
|
enddo
|
|
nsync=is1+is2+is3+is4+is5 !Number of correct hard sync symbols, 0-40
|
|
|
|
badsync=.false.
|
|
if(nsync .lt. 8) then
|
|
badsync=.true.
|
|
return
|
|
endif
|
|
|
|
bitmetrics=0.0
|
|
do nseq=1,nmax !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
|
|
if(nseq.eq.4) nsym=8
|
|
nt=4**nsym
|
|
do ks=1,NN-nsym+1,nsym
|
|
s2=0
|
|
do i=0,nt-1
|
|
csum=0
|
|
cterm=1
|
|
do j=0,nsym-1
|
|
ntone=mod(i/4**(nsym-1-j),4)
|
|
csum=csum+cs(graymap(ntone),ks+j)*cterm
|
|
cterm=cterm*conjg(cp(graymap(ntone)))
|
|
enddo
|
|
s2(i)=abs(csum)
|
|
enddo
|
|
ipt=1+(ks-1)*2
|
|
if(nsym.eq.1) ibmax=1
|
|
if(nsym.eq.2) ibmax=3
|
|
if(nsym.eq.4) ibmax=7
|
|
if(nsym.eq.8) ibmax=15
|
|
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
|
|
|
|
call normalizebmet(bitmetrics(:,1),2*NN)
|
|
call normalizebmet(bitmetrics(:,2),2*NN)
|
|
call normalizebmet(bitmetrics(:,3),2*NN)
|
|
call normalizebmet(bitmetrics(:,4),2*NN)
|
|
return
|
|
|
|
end subroutine get_fst240_bitmetrics
|