WSJT-X/libm65/cgen65.f90

100 lines
2.8 KiB
Fortran
Raw Normal View History

subroutine cgen65(message,mode65,samfac,nsendingsh,msgsent,cwave,nwave)
! Encodes a JT65 message into a wavefile.
! Executes in 17 ms on opti-745.
use packjt
parameter (NMAX=60*96000) !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,twopi,samfac,tsymbol
complex cwave(NMAX) !Generated complex wave file
integer dgen(12)
integer sent(63)
logical first
integer nprc(126)
real pr(126)
data nprc/1,0,0,1,1,0,0,0,1,1,1,1,1,1,0,1,0,1,0,0, &
0,1,0,1,1,0,0,1,0,0,0,1,1,1,0,0,1,1,1,1, &
0,1,1,0,1,1,1,1,0,0,0,1,1,0,1,0,1,0,1,1, &
0,0,1,1,0,1,0,1,0,1,0,0,1,0,0,0,0,0,0,1, &
1,0,0,0,0,0,0,0,1,1,0,1,0,0,1,0,1,1,0,1, &
0,1,0,1,0,0,1,1,0,0,1,0,0,1,0,0,0,0,1,1, &
1,1,1,1,1,1/
data twopi/6.283185307179586476d0/,first/.true./
save
if(first) then
do i=1,126
pr(i)=2*nprc(i)-1
enddo
first=.false.
endif
call chkmsg(message,cok,nspecial,flip) !See if it's a shorthand
if(nspecial.eq.0) then
call packmsg(message,dgen,itype) !Pack message into 72 bits
nsendingsh=0
if(iand(dgen(10),8).ne.0) nsendingsh=-1 !Plain text flag
call rs_encode(dgen,sent)
call interleave63(sent,1) !Apply interleaving
call graycode(sent,63,1) !Apply Gray code
nsym=126 !Symbols per transmission
tsymbol=4096.d0/11025.d0 !Time per symbol
else
nsendingsh=1 !Flag for shorthand message
nsym=32
tsymbol=16384.d0/11025.d0
endif
! Set up necessary constants
dt=1.d0/(samfac*96000.d0)
f0=118*11025.d0/1024
dfgen=mode65*11025.d0/4096.d0
t=0.d0
phi=0.d0
k=0
j0=0
ndata=nsym*96000.d0*samfac*tsymbol
do i=1,ndata
t=t+dt
j=int(t/tsymbol) + 1 !Symbol number, 1-126
if(j.ne.j0) then
f=f0
if(nspecial.ne.0 .and. mod(j,2).eq.0) f=f0+10*nspecial*dfgen
if(nspecial.eq.0 .and. flip*pr(j).lt.0.0) then
k=k+1
f=f0+(sent(k)+2)*dfgen
endif
dphi=twopi*dt*f
j0=j
endif
phi=phi+dphi
if(phi.gt.twopi) phi=phi-twopi
xphi=phi
cwave(i)=cmplx(cos(xphi),-sin(xphi))
enddo
cwave(ndata+1:)=0
nwave=ndata + 48000
call unpackmsg(dgen,msgsent)
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
if(nsendingsh.eq.1) then
if(nspecial.eq.2) msgsent='RO'
if(nspecial.eq.3) msgsent='RRR'
if(nspecial.eq.4) msgsent='73'
endif
return
end subroutine cgen65