WSJT-X/lib/gen24.f90
Joe Taylor da63d02038 Code for JT4 deep search now working well. (Needs some fine tuning, though.)
Message averaging has been tested, works well also.
Next: need to integrate these features and back-port into WSJT9.


git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2969 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2013-01-23 16:25:07 +00:00

87 lines
2.3 KiB
Fortran

subroutine gen24(message,mode4,samfac,ntxdf,iwave,nwave,sendingsh,msgsent,nmsg)
! Encode a JT4 message into a wavefile.
parameter (NMAX=60*11025) !Max length of wave file
character*22 message !Message to be generated
character*22 msgsent !Message as it will be received
character*3 cok !' ' or 'OOO'
real*8 t,dt,phi,f,f0,dfgen,dphi,pi,twopi,samfac,tsymbol
integer*2 iwave(NMAX) !Generated wave file
integer sendingsh
integer dgen(13)
integer*1 data0(13),symbol(216)
logical first
include 'prcom2.f'
data first/.true./
save
nsym=207 !Symbols per transmission
if(first) then
do i=1,nsym
pr2(i)=2*npr2(i)-1
enddo
pi=4.d0*atan(1.d0)
twopi=2.d0*pi
first=.false.
endif
call chkmsg(message,cok,nspecial,flip)
call packmsg(message,dgen) !Pack 72-bit message into 12 six-bit symbols
call entail(dgen,data0)
call unpackmsg(dgen,msgsent)
nbytes=(72+31+7)/8
call encode(data0,nbytes,symbol(2)) !Convolutional encoding
symbol(1)=0 !Reference phase
sendingsh=0
if(iand(dgen(10),8).ne.0) sendingsh=-1 !Plain text flag
call interleave24(symbol(2),1) !Apply JT4 interleaving
! Set up necessary constants
tsymbol=2520.d0/11025.d0
dt=1.d0/(samfac*11025.d0)
f0=118*11025.d0/1024 + ntxdf
dfgen=11025.d0/2520 !4.375 Hz
t=0.d0
phi=0.d0
j0=0
ndata=(nsym*11025.d0*samfac*tsymbol)/2
ndata=2*ndata
do i=1,ndata
t=t+dt
j=int(t/tsymbol) + 1 !Symbol number, 1-207
if(j.ne.j0) then
f=f0 + (npr2(j)+2*symbol(j)-1.5) * dfgen * mode4
if(flip.lt.0.0) f=f0+((1-npr2(j))+2*symbol(j)-1.5)*dfgen*mode4
dphi=twopi*dt*f
j0=j
endif
phi=phi+dphi
iwave(i)=32767.0*sin(phi)
enddo
do j=1,5512 !Put another 0.5 sec of silence at end
i=i+1
iwave(i)=0
enddo
nwave=i
if(flip.lt.0.0) then
do i=22,1,-1
if(msgsent(i:i).ne.' ') goto 10
enddo
10 msgsent=msgsent(1:i)//' OOO'
endif
do i=22,1,-1
if(msgsent(i:i).ne.' ') goto 20
enddo
20 nmsg=i
! write(*,3002) (symbol(i),i=1,207)
! 3002 format(70i1)
return
end subroutine gen24