mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-09-08 22:36:40 -04:00
Code cleanup and optimization still to be done! git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2970 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
177 lines
4.8 KiB
Fortran
177 lines
4.8 KiB
Fortran
subroutine decode24(dat,npts,dtx,dfx,flip,mode,mode4,decoded,ncount, &
|
|
deepbest,qbest,submode)
|
|
|
|
! Decodes JT65 data, assuming that DT and DF have already been determined.
|
|
|
|
parameter (MAXAVE=120)
|
|
real dat(npts) !Raw data
|
|
character decoded*22,deepmsg*22,deepbest*22
|
|
character*12 mycall,hiscall
|
|
character*6 hisgrid
|
|
character*72 c72
|
|
character submode*1
|
|
real*8 dt,df,phi,f0,dphi,twopi,phi1,dphi1
|
|
complex*16 cz,cz1,c0,c1
|
|
integer*1 symbol(207)
|
|
real*4 rsymbol(207,7)
|
|
real*4 sym(207)
|
|
integer nsum(7)
|
|
integer*1 data1(13) !Decoded data (8-bit bytes)
|
|
integer data4a(9) !Decoded data (8-bit bytes)
|
|
integer data4(12) !Decoded data (6-bit bytes)
|
|
integer amp,delta
|
|
integer mettab(0:255,0:1) !Metric table
|
|
integer nch(7)
|
|
integer npr2(207)
|
|
common/ave/ppsave(207,7,MAXAVE),nflag(MAXAVE),nsave,iseg(MAXAVE)
|
|
data mode0/-999/
|
|
data nsum/7*0/,rsymbol/1449*0.0/
|
|
data npr2/ &
|
|
0,0,0,0,1,1,0,0,0,1,1,0,1,1,0,0,1,0,1,0,0,0,0,0,0,0,1,1,0,0, &
|
|
0,0,0,0,0,0,0,0,0,0,1,0,1,1,0,1,1,0,1,0,1,1,1,1,1,0,1,0,0,0, &
|
|
1,0,0,1,0,0,1,1,1,1,1,0,0,0,1,0,1,0,0,0,1,1,1,1,0,1,1,0,0,1, &
|
|
0,0,0,1,1,0,1,0,1,0,1,0,1,0,1,1,1,1,1,0,1,0,1,0,1,1,0,1,0,1, &
|
|
0,1,1,1,0,0,1,0,1,1,0,1,1,1,1,0,0,0,0,1,1,0,1,1,0,0,0,1,1,1, &
|
|
0,1,1,1,0,1,1,1,0,0,1,0,0,0,1,1,0,1,1,0,0,1,0,0,0,1,1,1,1,1, &
|
|
1,0,0,1,1,0,0,0,0,1,1,0,0,0,1,0,1,1,0,1,1,1,1,0,1,0,1/
|
|
|
|
data nch/1,2,4,9,18,36,72/
|
|
save mettab,mode0,nsum,rsymbol
|
|
|
|
if(mode.ne.mode0) call getmet24(mode,mettab)
|
|
mode0=mode
|
|
twopi=8*atan(1.d0)
|
|
dt=2.d0/11025 !Sample interval (2x downsampled data)
|
|
df=11025.d0/2520.d0
|
|
nsym=206
|
|
amp=15
|
|
istart=nint(dtx/dt) !Start index for synced FFTs
|
|
if(istart.lt.0) istart=0
|
|
nchips=0
|
|
ich=0
|
|
qbest=0.
|
|
deepmsg=' '
|
|
ichbest=-1
|
|
|
|
! Should amp be adjusted according to signal strength?
|
|
|
|
! Compute soft symbols using differential BPSK demodulation
|
|
c0=0. !### C0=amp ???
|
|
k=istart
|
|
phi=0.d0
|
|
phi1=0.d0
|
|
|
|
40 ich=ich+1
|
|
nchips=nch(ich)
|
|
nspchip=1260/nchips
|
|
k=istart
|
|
phi=0.d0
|
|
phi1=0.d0
|
|
fac2=1.e-8 * sqrt(float(mode4))
|
|
do j=1,nsym+1
|
|
if(flip.gt.0.0) then
|
|
f0=1270.46 + dfx + (npr2(j)-1.5)*mode4*df
|
|
f1=1270.46 + dfx + (2+npr2(j)-1.5)*mode4*df
|
|
else
|
|
f0=1270.46 + dfx + (1-npr2(j)-1.5)*mode4*df
|
|
f1=1270.46 + dfx + (3-npr2(j)-1.5)*mode4*df
|
|
endif
|
|
dphi=twopi*dt*f0
|
|
dphi1=twopi*dt*f1
|
|
sq0=0.
|
|
sq1=0.
|
|
do nc=1,nchips
|
|
phi=0.d0
|
|
phi1=0.d0
|
|
c0=0.
|
|
c1=0.
|
|
do i=1,nspchip
|
|
k=k+1
|
|
phi=phi+dphi
|
|
phi1=phi1+dphi1
|
|
cz=dcmplx(cos(phi),-sin(phi))
|
|
cz1=dcmplx(cos(phi1),-sin(phi1))
|
|
if(k.le.npts) then
|
|
c0=c0 + dat(k)*cz
|
|
c1=c1 + dat(k)*cz1
|
|
endif
|
|
enddo
|
|
sq0=sq0 + real(c0)**2 + aimag(c0)**2
|
|
sq1=sq1 + real(c1)**2 + aimag(c1)**2
|
|
enddo
|
|
sq0=fac2*sq0
|
|
sq1=fac2*sq1
|
|
rsym=amp*(sq1-sq0)
|
|
r=rsym+128.
|
|
if(r.gt.255.0) r=255.0
|
|
if(r.lt.0.0) r=0.0
|
|
i4=nint(r)
|
|
if(i4.gt.127) i4=i4-256
|
|
if(j.ge.1) then
|
|
symbol(j)=i4
|
|
! rsymbol(j,ich)=rsymbol(j,ich) + rsym
|
|
rsymbol(j,ich)=rsym
|
|
sym(j)=rsym
|
|
endif
|
|
enddo
|
|
|
|
!### The following does simple message averaging:
|
|
! nsum(ich)=nsum(ich)+1
|
|
! do j=1,207
|
|
! sym(j)=rsymbol(j,ich)/nsum(ich)
|
|
! r=sym(j) + 128.
|
|
! if(r.gt.255.0) r=255.0
|
|
! if(r.lt.0.0) r=0.0
|
|
! i4=nint(r)
|
|
! if(i4.gt.127) i4=i4-256
|
|
! symbol(j)=i4
|
|
! enddo
|
|
!###
|
|
|
|
call extract4(sym,nadd,ncount,decoded) !Do the KV decode
|
|
|
|
qual=0. !Now try deep search
|
|
neme=1
|
|
mycall='VK7MO'
|
|
hiscall='W5LUA'
|
|
hisgrid='EM13'
|
|
call deep24(sym(2),neme,flip,mycall,hiscall,hisgrid,deepmsg,qual)
|
|
if(qual.gt.qbest) then
|
|
qbest=qual
|
|
deepbest=deepmsg
|
|
ichbest=ich
|
|
endif
|
|
|
|
if(ncount.ge.0) go to 100
|
|
if(mode.eq.7 .and. nchips.lt.mode4) go to 40
|
|
|
|
100 continue
|
|
!100 do i=1,9
|
|
! i4=data1(i)
|
|
! if(i4.lt.0) i4=i4+256
|
|
! data4a(i)=i4
|
|
! enddo
|
|
! write(c72,1100) (data4a(i),i=1,9)
|
|
!1100 format(9b8.8)
|
|
! read(c72,1102) data4
|
|
!1102 format(12b6)
|
|
|
|
! decoded=' '
|
|
! submode=' '
|
|
|
|
if(ncount.lt.0) then
|
|
decoded=deepbest
|
|
submode=char(ichar('A')+ichbest-1)
|
|
qual=qbest
|
|
endif
|
|
! if(decoded(1:6).eq.'000AAA') then
|
|
! decoded='***WRONG MODE?***'
|
|
! ncount=-1
|
|
! endif
|
|
|
|
! Save symbol spectra for possible decoding of average.
|
|
ppsave(1:207,1:7,nsave)=rsymbol(1:207,1:7)
|
|
|
|
return
|
|
end subroutine decode24
|